加藤 卓

BACKGROUND/AIM: De-differentiation is a key step for the progression of cancer cells. This study investigated the anti-tumor effect of kartogenin (KGN), which has the ability to differentiate cells, on prostate cancer (PC) cells. MATERIALS AND METHODS: The effects of KGN on androgen receptor (AR) nuclear localization, prostate-specific antigen (PSA) expression, and Smad2 activation as well as the growth of PC cell lines (LNCaP, 22Rv1 and PC-3) were analyzed. RESULTS: KGN significantly inhibited growth of AR-expressing LNCaP and 22Rv1 cells but not of AR-lacking PC-3 cells. KGN decreased AR nuclear localization and PSA expression, but did not enhance the anti-tumor effect of bicalutamide in LNCaP cells. KGN activated Smad2 both in the absence and presence of TGF-β1. KGN also inhibited growth of docetaxel-resistant PC cells, 22Rv1DR, and re-sensitized them to the agent. CONCLUSION: KGN has a potential as a novel therapeutic for PC patients after treatment failure.

We aimed to develop a sandwich ELISA to detect prostate-specific membrane antigen (PSMA) on small extracellular vesicles (EVs) using T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) as a capture molecule for EVs and to evaluate its diagnostic potential in urologic malignancies. First, we optimized the conditions for sandwich ELISA measuring the PSMA level on EVs captured from serum by Tim4 and found that the use of highly-purified EVs released from Tim4 that had captured EVs in serum reduced the background. Second, we confirmed its validity by studying mouse xenograft model for prostate cancer (PC). Lastly, we measured PSMA-EVs in serum of patients with urologic malignancies. The PSMA-EV levels were significantly higher in metastatic PC and castration-resistant PC (CRPC) patients than in therapy-naïve PC patients. In renal cell carcinoma (RCC) patients, PSMA-EVs were elevated in those with metastasis compared with those without metastasis, which may reflect the development of the neovasculature positive for PSMA in tumors. In conclusion, we developed a sandwich ELISA for detection of PSMA-EVs using highly-purified EVs isolated from serum by Tim4. Our results suggest that PSMA-EVs may be useful to diagnose and monitor not only PC but also RCC and possibly other hypervascular solid tumors.

BACKGROUND: Cabazitaxel (CBZ) is now widely used for prostate cancer (PC) patients resistant to docetaxel (DOC), however, most patients eventually acquire resistance. It will, therefore, be of great benefit to discover novel therapeutic target for the resistance. We aimed to identify candidate therapeutic targets for CBZ-resistance by proteomic analysis of extracellular vesicles (EVs) isolated from serum of DOC-resistant PC patients who later developed CBZ-resistance as well as those harvested from culture medium of DOC- and CBZ-resistant PC cell lines. METHODS: Using T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) conjugated to magnetic beads, EVs were purified from serum of PC patients with DOC-resistance that was collected before and after acquiring CBZ-resistance and conditioned medium of DOC-resistant (22Rv1DR) and CBZ-resistant (22Rv1CR) PC cell lines. Protein analysis of EVs was performed by nanoLC-MS/MS, followed by a comparative analysis of protein expression and network analysis. The cytotoxic effect of a phosphatidylinositol-3-kinase (PI3K) inhibitor, ZSTK474, was evaluated by WST-1 assay. The expression and phosphorylation of PI3K and PTEN were examined by western blot analysis. RESULTS: Among differentially regulated proteins, 77 and 61 proteins were significantly increased in EVs from CBZ-resistant PC cell line and patients, respectively. A comparison between the two datasets revealed that six proteins, fructose-bisphosphate aldolase, cytosolic nonspecific dipeptidase, CD63, CD151, myosin light chain 9, and peroxiredoxin-6 were elevated in EVs from both cell line and patients. Network analysis of the increased EV proteins identified pathways associated with CBZ-resistance including PI3K signaling pathway. ZSTK474 significantly inhibited growth of 22Rv1CR cells and improved their sensitivity to CBZ. In 22Rv1CR cells, PI3K was activated and PTEN that inhibits PI3K was deactivated. CONCLUSIONS: Proteomic analysis of serum EVs was successfully accomplished by using Tim-4 as a tool to isolate highly purified EVs. Our results suggest that the combination use of CBZ and PI3K inhibitor could be a promising treatment option for CBZ-resistant PC patients.

BACKGROUND/AIM: To identify novel biomarkers for prostate cancer (PC), we evaluated changes of miRNAs contained in serum small extracellular vesicles (EVs) in patients who received low dose rate prostate brachytherapy (BT). MATERIALS AND METHODS: EVs were isolated from the pooled serum of 10 PC patients prior to and 1 month after BT. miRNA profiling and quantitation in EVs was performed by microarray analysis and RT-digital PCR, respectively. Expression of miRNA-93 in prostate tissue was evaluated using the TCGA database and its level in EVs was determined in 25 patients before and 1, 3, 6 and 12 months after BT. RESULTS: Profiling and quantitation identified miRNA-93 as significantly down-regulated in EVs after BT. TCGA database analysis showed that miRNA-93 was increased in PC tissue. miRNA-93 in EVs significantly decreased in 3, 6 and 12 months after BT. CONCLUSION: miRNA-93 contained in serum EVs may be a novel diagnostic and monitoring biomarker for PC.

BACKGROUND: This study aimed to evaluate the association between clinical covariates or the prescribed radiation dose for the prostate and rectal hemorrhage in patients with prostate cancer (PCa) who received iodine-125 low-dose-rate brachytherapy (LDR-BT group) or the combination of LDR-BT and external beam radiation therapy (CMT group). METHODS AND MATERIALS: In this retrospective study, we reviewed the clinical records of 298 consecutive PCa patients with clinical stage T1c/T2 who underwent LDR-BT between August 2004 and August 2016 at a single institution. The prescribed minimum peripheral doses were 145 Gy for the LDR-BT group and 104 Gy for the CMT group. The dosimetric parameters analyzed were minimal dose received by 90% of the prostate gland, biologically effective dose, and rectal volume receiving 100% (RV100) or 150% of the prescribed dose. The endpoint of this study was the onset of any-grade clinical rectal hemorrhage after treatment. RESULTS: The median follow-up period was 6.8 years. The 5-year overall survival rate was found to be 98.3%, and two patients (0.7%) reported biochemical recurrence during follow-up period. A total of 33 patients (11%) experienced rectal hemorrhage. However, ≥ grade 2 rectal hemorrhage occurred in eight patients (2.7%). On multivariate analysis, CMT, RV100 ≥ 0.66 mL, and hemorrhoids before treatment were identified as predictors of rectal hemorrhage after radiation therapy. CONCLUSIONS: Maximal reduction of the rectal dose seems very important to prevent serious rectal hemorrhage. In addition, we should consider the risk of rectal toxicities in patients with abnormalities in the rectal mucosa, especially hemorrhoids.

70歳男。主訴は右下肢痛であった。FDG-PET検査で上行結腸、恥骨および右大腿骨に異常集積を認め、腫瘍マーカーはPSA 20.57ng/ml、CEA 108.5ng/ml、CA19-9 1002.1U/mlと高値であった。大腸内視鏡検査で上行結腸に腺癌group 5と診断され、単孔式腹腔鏡下結腸右半切除術を施行し、病理組織学的診断はステージIIIAの高異型度腺癌であった。恥骨の開放骨生検では前立腺癌恥骨転移と診断し、前立腺癌に対しビカルタミド、リュープロレリンによる治療を開始した。大腿骨骨転移に対してはデノスマブ併用放射線治療を施行し、以降PSAは測定感度以下でコントロール良好であった。初診2年後よりCEA、CA19-9の上昇を認め、FDG-PET検査で恥骨病変の集積の増大を認めたためCTガイド下骨生検を再度施行し、上行結腸癌骨転移の診断となった。カペシタビンおよびオキサリプラチンによる治療を開始したが徐々に病状が進行し、初診から3年9ヵ月の経過で死亡した。

A 70-year-old man visited a private hospital with the chief complaint of right lower limb pain. Fluorodeoxyglucose-emission tomography (FDG-PET) showed abnormal uptake in the pubic bone, right femur, and ascending colon. The patient was referred to our hospital for further evaluation. The following tumor marker levels were found : prostate-specific antigen (PSA) 20.57 ng/ml, carcinoembryonic antigen (CEA) 108.5 ng/ml, carbohydrate antigen 19-9 (CA19-9) 1,002.1 U/ml. An open pubic bone biopsy was performed. The pathological diagnosis was metastatic adenocarcinoma from prostate cancer. Prostate and ascending colon cancers were clinically diagnosed as T2bN0M1b and T2N0M0, respectively. Laparoscopic colectomy was performed. Androgen deprivation therapy started immediately and the serum PSA level was maintained at <0.2 ng/ml during the follow-up period. However, the CEA and CA19-9 were higher than the normal level 2 years after the surgery. In addition, the FDG-PET revealed abnormal uptake in the pubic bone. Thus, a pubic bone biopsy was performed again. The histological diagnosis was metastatic adenocarcinoma from the ascending colon cancer. Although the patient received combination chemotherapy, he died of colon cancer.

OBJECTIVE: To investigate long-term changes in lower urinary tract symptoms in patients with prostate cancer (PCa) who underwent low-dose-rate brachytherapy with iodine-125 (LDR-BT). PATIENTS AND METHODS: In this retrospective study, 313 patients with localized PCa underwent LDR-BT at Gifu University hospital between August 2004 and December 2013. The International Prostate Symptom Score (IPSS), Overactive Bladder Symptom Score (OABSS), and quality of life due to urinary symptoms (IPSS-QOL) were measured before LDR-BT; at 1, 3, 6, 9, 12, 24, 36, 48, and 60 months after LDR-BT; and annually thereafter. Study endpoints were chronological changes in IPSS, OABSS, and IPSS-QOL compared to pretreatment values. A multivariable nonlinear regression model with robust sandwich estimator evaluated association between outcomes and time with adjustment for covariates. RESULTS: All scores worsened immediately after LDR-BT compared to preoperative scores. However, symptoms improved with time and returned to baseline in 18-36 months. After a 5-year follow-up after LDR-BT, OABSS significantly worsened in almost all patients compared to baseline although there were gradual improvements in less than 5 years after LDR-BT. CONCLUSIONS: Our results may be of clinical importance in selecting treatment modalities for patients with localized PCa and long-term survival after definitive therapy.

Background: Docetaxel is first-line chemotherapy for castration-resistant prostate cancer (CRPC), but most patients acquire docetaxel resistance. CD44 has been shown to be involved in drug resistance of cancers including prostate cancer. We hypothesized that CD44 in serum exosomes could be a diagnostic marker for docetaxel resistance in CRPC patients. In this study, we examined CD44 protein and mRNA expression in cell lysates and exosomes isolated from prostate cancer cells, evaluated the effect of CD44v8-10 knockdown on docetaxel sensitivity and measured CD44 mRNA copy numbers contained in serum exosomes in prostate cancer patients. Materials and methods: Docetaxel-sensitive PC-3 prostate cancer cells and docetaxel-resistant PC-3R cells established previously from parental PC-3 cells were used. CD44v8-10 knockdown was performed by siRNA transfection. Blood was collected from 50 docetaxel-naïve and 10 docetaxel-resistant patients and 15 control males. CD44 protein expression was evaluated by Western blotting. CD44 mRNA expression was measured by RT-digital PCR. Results: The levels of CD44v8-10 protein and mRNA in cell lysates and exosomes were higher in PC-3R cells than in PC-3 cells. CD44v8-10 knockdown significantly increased docetaxel sensitivity of PC-3R cells. The CD44v8-10 mRNA copy numbers in serum exosomes were higher in docetaxel-resistant patients than in docetaxel-naïve patients and control males (median 46, 12 and 17 copies/mL serum, respectively, P = 0.032). In contrast, the serum exosomal mRNA copy numbers of CD44 standard isoform (CD44s) were not different among 3 groups (median 25, 14 and 13 copies/mL serum, respectively, P = 0.150). Conclusions: CD44v8-10 may be involved in docetaxel resistance in prostate cancer and serum exosomal CD44v8-10 mRNA could be a diagnostic marker for docetaxel-resistant CRPC.

Granulocyte colony-stimulating factor (G-CSF)-producing bladder cancer is a rare variant subtype of bladder cancer with a poor prognosis. Pembrolizumab has improved overall survival in bladder cancer and is widely used as a standard second-line treatment. However, no reports on G-CSF-producing cancer treated by pembrolizumab are available. We report a case of the pathologically evaluated antitumor effect of pembrolizumab, a programmed death-1 immune checkpoint inhibitor antibody, in G-CSF-producing bladder cancer. A 53-year-old male patient underwent 4 courses chemotherapy with a combination of gemcitabine and carboplatin before a radical cystectomy with ileal neobladder. Four months after the surgery, local recurrence was detected in the pelvis and therefore pembrolizumab was used. One week after its administration, the patient showed increased mucus in his urine. A computed tomography scan and cystoscopy revealed a fistula between the ileum and the neobladder. He subsequently underwent partial ileectomy and repair of the neobladder-ileum fistula. Pathology-diagnosed tumor response to pembrolizumab in the metastatic tumor showed predominant infiltration by lymphocytes, unlike that in the primary bladder cancer. The patient has shown complete response and no recurrence at 1 year after the beginning of treatment, and therapy is still continuing. Although many questions still remain regarding the treatment of G-CSF-producing bladder cancer, pathologic evaluation of the present case suggests that treatment with pembrolizumab may be one option for G-CSF-producing bladder cancer that has failed chemotherapy treatment, similar to non-G-CSF-producing bladder cancer.

Ten years ago, a seventy-year-old female underwent extirpation of a left retroperitoneal tumor that was 58×36 mm in size. The pathological diagnosis was malignant peripheral nerve sheath tumor (MPNST) at that time. The patients visited our hospital with the chief complaint of back pain at ten years after surgery. Computer tomography (CT) showed recurrent tumors at the pancreas and the left kidney. Fine-needle aspiration biopsy was performed because of the possibility of pancreatic tumor. The pathological diagnosis was the recurrence of MPNST. The patient underwent extirpation of the recurrent tumors along with the pancreatic body and tail, transverse colon, spleen and left kidney. The definitive diagnosis was dedifferentiated liposarcoma with murine double minute 2 (MDM2) gene amplification and positive of p16Ink4 (p16). The previously resected tumor also revealed MDM2 gene amplification and positive of p16. Based on these results, our diagnosis in this case was recurrence of dedifferentiated liposarcoma. At 6 months after surgery, the patient had no local recurrence or distant metastases.

Radiation therapy with permanent iodine-125 implant brachytherapy is well established for curable prostate cancer. To maximize the therapeutic potential of brachytherapy, delivered radiation doses have been increased accompanied by refined intraoperative procedures of radioactive seeds placement. However, dose escalation is a double-edged sword in prostate brachytherapy; it could induce rectal toxicity, yet is successful in curable treatment in prostate cancer. To reduce irradiation of the rectum, the SpaceOAR® system has been used to inject synthetic polyethylene glycol hydrogel between the prostate and the rectum. The present report describes a case of spontaneous healing of rectal penetration associated with SpaceOAR® hydrogel.

BACKGROUND: The risk of malignant neoplasms increases in kidney transplantation (KT) recipients (KTRs). However, Japanese registry studies have not been reported since 2000. METHODS: We retrospectively reviewed the medical records of 346 patients who underwent KT at Gifu University Hospital, Japan since 2000. Patients were divided into two groups based on whether they developed malignancy after KT or not. The incidence, type of malignancy, risk factors, and prognosis for malignancy were examined. RESULTS: In this study, 22 de novo malignant neoplasms were identified in 20 KTRs (7.3%), with a median follow-up period of 8.2 years. Cumulative incidence of any malignant neoplasms was 1.1% within 1 year and 4.4% within 5 years. The 5-year overall survival (OS) rates were 71.8% in KTRs with malignant neoplasms and 98.6% in KTRs without malignant neoplasms. Uni- and multivariate analysis revealed that age at KT and acute rejection (AR) episode were significant predictors for incidence of malignancy. CONCLUSIONS: The development of malignant neoplasms was associated with poor OS and graft survival. We consider that appropriate screening and investigation of symptoms are important for KTRs, particularly for older KTRs at transplantation and those with AR episode.

Prostate cancer incidence and mortality rates are higher in African-American (AA) than in European-American (EA) men. The main objective of this study was to elucidate the role of miR-130b as a contributor to prostate cancer health disparity in AA patients. We also determined whether miR-130b is a prognostic biomarker and a new therapeutic candidate for AA prostate cancer. A comprehensive approach of using cell lines, tissue samples, and the TCGA database was employed. We performed a series of functional assays such as cell proliferation, migration, invasion, RT2-PCR array, qRT-PCR, cell cycle, luciferase reporter, immunoblot, and IHC. Various statistical approaches such as Kaplan-Meier, uni-, and multivariate analyses were utilized to determine the clinical significance of miR-130b. Our results showed that elevated levels of miR-130b correlated with race disparity and PSA levels/failure and acted as an independent prognostic biomarker for AA patients. Two tumor suppressor genes, CDKN1B and FHIT, were validated as direct functional targets of miR-130b. We also found race-specific cell-cycle pathway activation in AA patients with prostate cancer. Functionally, miR-130b inhibition reduced cell proliferation, colony formation, migration/invasion, and induced cell-cycle arrest. Inhibition of miR-130b modulated critical prostate cancer-related biological pathways in AA compared with EA prostate cancer patients. In conclusion, attenuation of miR-130b expression has tumor suppressor effects in AA prostate cancer. miR-130b is a significant contributor to prostate cancer racial disparity as its overexpression is a risk factor for poor prognosis in AA patients with prostate cancer. Thus, regulation of miR-130b may provide a novel therapeutic approach for the management of prostate cancer in AA patients.

Appropriate protocol for the sequential treatment of metastatic renal cell carcinoma (mRCC) has not been established yet. Some mRCC cases with favorable risk were reported to achieve complete remission and durable response using interferon alfa (IFNα) + low dose interleukin-2 (IL-2). Cytokine therapies may be suitable for some patients with mRCC as first-line therapy. The present study is a phase III, investigator-initiated, multicenter, prospective randomized controlled trial investigating patients with low and intermediate risk mRCC classified by Memorial Sloan-Kettering Cancer Center risk criteria to evaluate the efficacy and safety of sequential treatment with cytokine (IFNα + IL-2) as first-line and axitinib as second-line therapy versus sequential treatment with sunitinib as first-line and axitinib as second-line therapy, which is the current standard treatment for patients with favorable risk. The target sample size was set at 72 patients per group (total 144 cases). The study duration is 7 years, and the duration for recruitment is 4 years. Our expectation of this trial is to clarify first- and second-line sequential treatment for mRCC better, especially in patients with favorable risk and some with intermediate risk. The results of this trial will certainly contribute to new information for the strategy of first- and second-line sequential treatment for mRCC. Trial registration: University hospital Medical Information Network (UMIN) Center identifier UMIN 000012522.

2018年にロボット支援膀胱全摘除術が保険収載となったことにより、今後施行症例が増加すると思われる。しかし、膀胱全摘除術は、周術期合併症および死亡率とも未だ高い術式である。そのため、導入初期はプロクターによる指導や、適応の是非について慎重に検討する必要がある。一方尿変向術は、体腔内で尿路変向を行う。いわゆるICUDはあまり行われていない。ICUD普及のために、術式の標準化が必要と思われる。(著者抄録)

Unlike urinary tract infection (UTI), asymptomatic bacteriuria (ABU) should not be treated, with some exceptions such as pregnant women and patients who will undergo traumatic urologic interventions. However, there has been no clinically available marker for their differential diagnosis. Exosomes or small extracellular vesicles carry proteins contained in cells from which they are derived, thus having the potential as a biomarker of several diseases. On the basis of the hypothesis that the molecular signature of exosomes in urine may differ between UTI and ABU patients, we examined if urinary exosomes could serve as a marker for their differential diagnosis. Exosomes were isolated by ultracentrifugation or affinity-based method from cell culture medium of monocytic THP-1 and uroepithelial SV-HUC-1 cells and human urine. Protein expression was examined by Western blot analysis, ELISA, and CLEIA. The results showed that the levels of intracellular signalling molecules Akt and ERK and transcription factor NF-κB increased in exosomes isolated from THP-1 and SV-HUC-1 cells cocultured with Escherichia coli and/or treated with lipopolysaccharide. In urinary exosomes of UTI patients, Akt significantly diminished, and an exosomal marker CD9 showed a trend to decrease after treatment with antimicrobial agents. More importantly, Akt and CD9 levels in urinary exosomes were higher in UTI patients than in ABU patients, which was also observed after correction by urine creatinine. Collectively, these results suggest that Akt and CD9 in urinary exosomes could be useful markers for differential diagnosis of UTI and ABU.

The patient underwent laparoscopic left radical nephrectomy for clear cell renal cell carcinoma (ccRCC). After surgery, the patient had multiple lung metastases and underwent the combination therapy of radiofrequency ablation, interferon-alpha, and inteleukin-2. Thereafter, computed tomography showed multiple lymph node and brain metastases. The patient was administered targeted therapy and radiation. Eventually, the patient suddenly complained of dyspnea. An echocardiogram, coronary angiography and magnetic resonance imaging suggested acute heart failure and pericardial effusion due to a metastatic tumor in the cardiac anteroseptal and posterior wall. Nivolumab was administered for cardiac metastases. The patient has been in stable condition with no progression of cardiac metastases after the administration of nivolumab for 22 months.

Radical cystectomy remains the gold standard for treatment of muscle-invasive bladder cancer. Robot-assisted radical cystectomy has technical advantages over laparoscopic radical cystectomy and has emerged as an alternative to open radical cystectomy. Despite the advancements in robotic surgery, experience with total intracorporeal reconstruction of urinary diversion remains limited. Most surgeons have carried out the hybrid approach of robot-assisted radical cystectomy and extracorporeal reconstruction of urinary diversion, as intracorporeal reconstruction of urinary diversion remains technically challenging. However, intracorporeal reconstruction of urinary diversion might potentially proffer additional benefits, such as decreased fluid loss, reduction in estimated blood loss and a quicker return of bowel function. The adoption of intracorporeal ileal neobladder reconstruction has hitherto been limited to high-volume academic institutions. In the present review, we compare the totally intracorporeal robot-assisted radical cystectomy approach with open radical cystectomy and robot-assisted radical cystectomy + extracorporeal reconstruction of urinary diversion in muscle-invasive bladder cancer patients.

OBJECTIVE: To examine the association between human papillomavirus (HPV) infection and penile cancer among Japanese patients. METHODS: Thirty-four patients with penile cancer were enrolled in this study. DNA was extracted from paraffin-embedded tumor tissue samples, and HPV-DNA tests and genotyping were performed. For all of the samples, in situ hybridization (ISH) was performed to locate HPV-DNA in tumor tissue. Furthermore, expression levels of p16-INK4a, mini-chromosome maintenance protein 7(mcm-7), HPV-L1, and Ki-67 were analyzed using immunohistochemical methods. RESULTS: HPV and high-risk (HR)-HPV were detected in 14 (41.1%; 95% confidence interval (CI) 24.6-57.7%) and 12 (35.2%; 95% CI 19.2-51.4%) cases, respectively. HPV16 was the most frequently detected HPV type. Among the HR-HPV-positive cases, a punctate HR-HPV-DNA signal pattern was detected by ISH in tumor cell nuclei. P16-INK4a was expressed in 66.7% (95% CI 42.8-90.1%) of HR-HPV-positive cases and was significantly more frequent and stronger in HR-HPV-positive cases than in HPV-negative cases. There was no significant difference in the occurrence or distribution of mcm-7 or Ki-67 expression between HPV-positive and HPV-negative cases. HPV-L1 expression was not observed in any of the cases examined. CONCLUSIONS: HPV infection may have had an etiological role in 41% of the examined cases of penile cancer in Japan.

Cytochrome P450 1B1 (CYP1B1) converts xenobiotics to carcinogens and how lifestyle choices may interact with CYP1B1 polymorphisms and affect prostate cancer risk was assessed. Blood genomic DNA from a Caucasian population was analysed at polymorphic sites of the 5' untranslated region of CYP1B1 using TaqMan genotyping assays. Overall, drinker status and minor alleles at rs2551188, rs2567206 and rs10175368 were associated with prostate cancer. Linkage was observed between rs2551188, rs2567206, rs2567207 and rs10175368, and the G-C-T-G haplotype (major allele at respective sites) was decreased in cancer. Interestingly when classified by lifestyle factors, no associations of genotypes were found for non-smokers and non-drinkers, whereas on the contrary, minor type at rs2567206 and rs10175368 increased and major G-C-T-G decreased risk for cancer among smokers and drinkers. Interestingly, rs2551188, rs2567206 and rs10175368 minor genotypes correlated with increased tissue CYP1B1 as determined by immunohistochemistry. Further, rs10175368 enhanced luciferase activity and mobility shift show stronger binding of nuclear factor for the minor allele. These results demonstrate smoking and alcohol consumption to modify the risks of CYP1B1 polymorphisms for prostate cancer which may be through rs10175368, and this is of importance in understanding their role in the pathogenesis and as a biomarker for this disease.

miRNAs are implicated in regulating cancer progression and metastasis. Here, we show that miR-720 is positively associated with renal cell carcinoma (RCC). Elevated levels of miR-720 were observed in a panel of RCC cell lines and clinical tissues compared with nonmalignant cell line and normal samples. Loss of miR-720 function inhibited proliferation, migration, and invasion and induced apoptosis in RCC cell lines in vitro and repressed tumor growth in xenograft mouse models. Conversely, gain of miR-720 function in nonmalignant HK-2 cells induced procancerous characteristics. Silencing of miR-720 caused a marked induction in the levels of endogenous αE-catenin and E-cadherin protein levels in anti720 transfected cells compared with control, whereas miR-720 overexpression in RCC cell lines reduced activity of a luciferase reporter gene fused to the wild-type αE-catenin or E-cadherin 3'UTR compared with nonspecific 3'UTR control, indicating that αE-catenin-E-cadherin complex is a direct and functional target of miR-720 in RCC. We also observed attenuation of β-catenin, CD44, and Akt expression in RCC cells transfected with miR-720 inhibitor compared with control. Furthermore, miR-720 exhibited clinical significance in RCC. Expression of miR-720 significantly distinguished malignant from normal samples. Elevated miR-720 levels positively correlated with higher Fuhrman grade, pathologic stage, and poor overall survival of RCC patients. These findings uncover a new regulatory network in RCC involving metastasis-promoting miR-720 that directly targets expression of key metastasis-suppressing proteins E-cadherin and αE-catenin complex. These results suggest that therapeutic regulation of miR-720 may provide an opportunity to regulate EMT and metastasis in RCC. Mol Cancer Ther; 16(12); 2840-8. ©2017 AACR.

The proteoglycan versican (VCAN) promotes tumor progression and enhances metastasis in several cancers; however, its role in clear cell renal cell carcinoma (ccRCC) remains unknown. Recent evidence suggests that VCAN is an important target of chromosomal 5q gain, one of the most prevalent genetic abnormalities in ccRCC. Thus, we investigated whether VCAN expression is associated with the pathogenesis of ccRCC. VCAN expression was analyzed using three RCC and normal kidney cell lines as well as a clinical cohort of 84 matched ccRCC and normal renal tissues. Functional analyses on growth and progression properties were performed using VCAN-depleted ccRCC cells. Microarray expression profiling was employed to investigate the target genes and biologic pathways involved in VCAN-mediated ccRCC carcinogenesis. ccRCC had elevated VCAN expression in comparison with normal kidney in both cell lines and clinical specimens. The elevated expression of VCAN was significantly correlated with metastasis (P < 0.001) and worse 5-year overall survival after radical nephrectomy (P = 0.014). In vitro, VCAN knockdown significantly decreased cell proliferation and increased apoptosis in Caki-2 and 786-O cells, and this was associated with alteration of several TNF signaling-related genes such as TNFα, BID, and BAK Furthermore, VCAN depletion markedly decreased cell migration and invasion which correlated with reduction of MMP7 and CXCR4. These results demonstrate that VCAN promotes ccRCC tumorigenesis and metastasis and thus is an attractive target for novel diagnostic, prognostic, and therapeutic strategies.Implications: This study highlights the oncogenic role of VCAN in renal cell carcinogenesis and suggests that this gene has therapeutic and/or biomarker potential for renal cell cancer. Mol Cancer Res; 15(7); 884-95. ©2017 AACR.

BACKGROUND: Exosomes or extracellular vesicles have the potential as a diagnostic marker for various diseases including cancer. In order to identify novel exosomal markers for prostate cancer (PC), we performed proteomic analysis of exosomes isolated from PC cell lines and examined the usefulness of the marker in patients. METHODS: Exosomes isolated by differential centrifugation from the culture medium of androgen-dependent LNCaP prostate cancer cell line and its sublines of partially androgen-independent C4, androgen-independent C4-2 and bone metastatic C4-2B were subjected to iTRAQ-based proteomic analysis. Exosomes were also isolated by immunocapture and separated by size exclusion chromatography and density gradient centrifugation. Protein expression was determined by Western blot analysis. GGT activity was measured using a fluorescent probe, γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG). Immunohistochemical analysis of tissues was performed using anti-GGT1 antibody. RESULTS: Among proteins upregulated in C4-2 and C4-2B cells than in LNCaP cells, we focused on gamma-glutamyltransferase 1 (GGT1), a cell-surface enzyme that regulates the catabolism of extracellular glutathione. The levels of both GGT1 large and small subunits were elevated in exosomes isolated from C4-2 and C4-2B cells by differential centrifugation and by immunocapture with anti-CD9 or -prostate-specific membrane antigen (PSMA) antibody. In cell lysates and exosomes, GGT1 expression correlated with GGT activity. Size exclusion chromatography of human serum demonstrated the presence of GGT activity and GGT1 subunits in fractions positive for CD9. Density gradient centrifugation revealed the co-presence of GGT1 subunits with CD9 in exosomes isolated by differential centrifugation from human serum. Since GGT activity correlated with GGT1 expression in serum exosomes isolated by differential centrifugation, we measured serum exosomal GGT activity in patients. Unexpectedly, we found that serum exosomal GGT activity was significantly higher in PC patients than in benign prostatic hyperplasia (BPH) patients. In support of this finding, immunohistochemical analysis showed increased GGT1 expression in PC tissues compared with BPH tissues. CONCLUSIONS: Our results suggest that serum exosomal GGT activity could be a useful biomarker for PC.

The incidence of prostate cancer (PCa) among African-Americans (AfA) is significantly higher than Caucasian-Americans (CaA) but the genetic basis for this disparity is not known. To address this problem, we analyzed miRNA expression in AfA (n = 81) and CaA (n = 51) PCa patients. Here, we found that miR-24 is differentially expressed in AfA and CaA PCa patients and attempt to clarify its role in AfA patients. Also, the public sequencing data of the miR-24 promoter confirmed that it was highly methylated and down-regulated in PCa patients. Utilizing a VAMCSF and NDRI patient cohorts, we discovered that miR-24 expression was linked to a racial difference between AfA/CaA PCa patients. Interestingly, miR-24 was restored after treatment of PCa cells with 5Aza-CdR in an AfA cell line (MDA-PCa-2b), while restoration of miR-24 was not observed in CaA cells, DU-145. Ectopic expression of miR-24 showed decreased growth and induced apoptosis, though the effect was less in the CaA cell line compared to the AfA cell line. Finally, we found unique changes in biological pathways and processes associated with miR-24 transfected AfA cells by quantitative PCR-based gene expression array. Evaluation of the altered pathways showed that AR, IGF1, IGFBP5 and ETV1 were markedly decreased in the AfA derived cell line compared with CaA cells, and there was a reciprocal regulatory relationship of miR-24/target expression in prostate cancer patients. These results demonstrate that miR-24 may be a central regulator of key events that contribute to race-related tumorigenesis and has potential to be a therapeutic agent for PCa treatment.

African-Americans are diagnosed with more aggressive prostate cancers and have worse survival than Caucasians, however a comprehensive understanding of this health disparity remains unclear. To clarify the mechanisms leading to this disparity, we analyzed the potential involvement of miR-34b expression in African-Americans and Caucasians. miR-34b functions as a tumor suppressor and has a multi-functional role, through regulation of cell proliferation, cell cycle and apoptosis. We found that miR-34b expression is lower in human prostate cancer tissues from African-Americans compared to Caucasians. DNA hypermethylation of the miR-34b-3p promoter region showed significantly higher methylation in prostate cancer compared to normal samples. We then sequenced the promoter region of miR-34b-3p and found a chromosomal deletion in miR-34b in African-American prostate cancer cell line (MDA-PCA-2b) and not in Caucasian cell line (DU-145). We found that AR and ETV1 genes are differentially expressed in MDA-PCa-2b and DU-145 cells after overexpression of miR-34b. Direct interaction of miR-34b with the 3' untranslated region of AR and ETV1 was validated by luciferase reporter assay. We found that miR-34b downregulation in African-Americans is inversely correlated with high AR levels that lead to increased cell proliferation. Overexpression of miR-34b in cell lines showed higher inhibition of cell proliferation, apoptosis and G1 arrest in the African-American cells (MDA-PCa-2b) compared to Caucasian cell line (DU-145). Taken together, our results show that differential expression of miR-34b and AR are associated with prostate cancer aggressiveness in African-Americans.

Advanced bladder cancer is treated mainly with gemcitabine and cisplatin, but most patients eventually become resistance. Androgen receptor (AR) signaling has been implicated in bladder cancer as well as other types of cancer including prostate cancer. In this study, we investigated the expression and role of AR in gemcitabine-resistant bladder cancer cells and also the potential of enzalutamide, an AR inhibitor, as a therapeutic for the chemoresistance. First of all, we established gemcitabine-resistant T24 cells (T24GR) from T24 bladder cancer cells and performed gene expression profiling. Microarray analysis revealed upregulation of AR expression in T24GR cells compared with T24 cells. AR mRNA and protein expression was confirmed to be increased in T24GR cells, respectively, by quantitative RT-PCR and western blot analysis, which was associated with more potent AR transcriptional activity as measured by luciferase reporter assay. The copy number of AR gene in T24GR cells determined by PCR was twice as many as that of T24 cells. AR silencing by siRNA transfection resulted in inhibition of proliferation of T24GR cells. Cell culture in charcoal-stripped serum and treatment with enzalutamide inhibited growth of T24GR cells, which was accompanied by cell cycle arrest. AR transcriptional activity was found to be reduced in T24GR cells by enzalutamide treatment. Lastly, enzalutamide also inhibited cell proliferation of HTB5 bladder cancer cells that express AR and possess intrinsic resistance to gemcitabine. Our results suggest that enzalutamide may have the potential to treat patients with advanced gemcitabine-resistant bladder cancer with increased AR expression.

Prostate carcinogenesis involves alterations in several signaling pathways, the most prominent being the PI3K/AKT pathway. This pathway is constitutively active and drives prostate cancer (PCa) progression to advanced metastatic disease. PTEN, a critical tumor and metastasis suppressor gene negatively regulates cell survival, proliferation, migration and angiogenesis via the PI3K/Akt pathway. PTEN is mutated, downregulated/dysfunctional in many cancers and its dysregulation correlates with poor prognosis in PCa. Here, we demonstrate that microRNA-4534 (miR-4534) is overexpressed in PCa and show that miR-4534 is hypermethylated in normal tissues and cell lines compared to PCa tissues/cells. miR-4534 exerts its oncogenic effects partly by downregulating the tumor suppressor PTEN gene. Knockdown of miR-4534 impaired cell proliferation, migration/invasion and induced G0/G1 cell cycle arrest and apoptosis in PCa. Suppression of miR-4534 and its effects on tumor growth was confirmed in a xenograft mouse model. We performed parallel experiments in non-cancer RWPE1 cells by overexpessing miR-4534 followed by functional assays. Overexpression of miR-4534 induced pro-cancerous characteristics in this non-cancer cell line. Statistical analyses revealed that miR-4534 has potential to independently distinguish malignant from normal tissues and positively correlated with poor overall and PSA recurrence free survival. Taken together, our results show that depletion of miR-4534 in PCa induces a tumor suppressor phenotype partly through induction of PTEN. These results have important implications for identifying and defining the role of new PTEN regulators such as microRNAs in prostate tumorigenesis. Understanding aberrantly overexpressed miR-4534 and its downregulation of PTEN will provide mechanistic insight and therapeutic targets for PCa therapy.

Cytochrome P450 (CYP) 1A1 is a phase I enzyme that can activate various compounds into reactive forms and thus, may contribute to carcinogenesis. In this study, we investigated the expression, methylation status, and functional role of CYP1A1 on prostate cancer cells. Increased expression of CYP1A1 was observed in all cancer lines (PC-3, LNCaP, and DU145) compared to BPH-1 (P < 0.05); and was enhanced further by 5-aza-2'-deoxycytidine treatment (P < 0.01). Methylation-specific PCR (MSP) and sequencing of bisulfite-modified DNA of the xenobiotic response element (XRE) enhancer site XRE-1383 indicated promoter methylation as a regulator of CYP1A1 expression. In tissue, microarrays showed higher immunostaining of CYP1A1 in prostate cancer than normal and benign prostatic hyperplasia (BPH; P < 0.001), and methylation analyses in clinical specimens revealed significantly lower methylation levels in cancer compared to BPH at all enhancer sites analyzed (XRE-1383, XRE-983, XRE-895; P < 0.01). Interestingly, smoking affected the XRE-1383 site where the methylation level was much lower in cancer tissues from smokers than non-smokers (P < 0.05). CYP1A1 levels are thus increased in prostate cancer and to determine the functional effect of CYP1A1 on cells, we depleted the gene in LNCaP and DU145 by siRNA. We observe that CYP1A1 knockdown decreased cell proliferation (P < 0.05) and increased apoptosis (P < 0.01) in both cell lines. We analyzed genes affected by CYP1A1 silencing and found that apoptosis-related BCL2 was significantly down-regulated. This study supports an oncogenic role for CYP1A1 in prostate cancer via promoter hypomethylation that is influenced by tobacco smoking, indicating CYP1A1 to be a promising target for prostate cancer treatment.

BACKGROUND/AIM: Advanced renal cell carcinoma is treated with mammalian target of rapamycin (mTOR) inhibitors or tyrosine kinase inhibitors (TKIs). The effects of these drugs are, however, limited and novel treatment strategies are required. Clear-cell type renal cell carcinoma (ccRCC) is chemo-resistant, in part, due to expression of multidrug resistance proteins such as p-glycoprotein. Cabazitaxel, a tubulin-binding taxane drug used for castration-resistant prostate cancer, has less affinity for p-glycoprotein compared to docetaxel. In the current study, the effects of docetaxel and cabazitaxel on ccRCC cells were investigated. MATERIALS AND METHODS: The expression of p-glycoprotein was evaluated in the ccRCC cell lines, Caki-1, KMRC-1 and OS-RC-2 by western blotting. Cells were treated with cabazitaxel or docetaxel, and growth kinetics and tubulin polymerization were determined by the WST-1 assay and cell-based tubulin polymerization assay, respectively. Intracellular drug concentrations were measured by chromatography. AKT activation after treatment was examined by western blotting. RESULTS: All ccRCC cell lines expressed p-glycoprotein. Cabazitaxel inhibited cell growth and induced tubulin polymerization more potently than docetaxel. The intracellular concentration of cabazitaxel was much higher than docetaxel in all cell lines. Both docetaxel and cabazitaxel inhibit AKT phosphorylation at 5 min among three cells. CONCLUSION: Cabazitaxel inhibits growth of ccRCC cells expressing p-glycoprotein and could thus be possibly used for advanced ccRCC patients in combination with targeted-therapy enhancing their effects.

症例1は69歳男で、左腎癌に対する左腎摘除術後、局所再発、骨・肝・肺転移出現のためソラフェニブ内服を開始した。転移巣の完全消失(CR)後も継続したが、心筋梗塞を発症し、左冠動脈回旋枝と右冠動脈に経皮的冠動脈ステントを留置した。ソラフェニブ内服は中止し、1年8ヵ月経過して腎癌はCRを維持している。症例2は69歳男で、右腎癌に対し右腎摘除術後、多発肺転移を認め、ソラフェニブを10ヵ月継続したが、急性心筋梗塞を発症した。右冠動脈および左冠動脈前下行枝に対しカテーテル治療を行ったが、心不全が進行し第10病日に死亡した。症例3は59歳男で、右腎癌に対し右腎摘除術後、肺転移を認め、ソラフェニブを8ヵ月間継続したが、心筋梗塞を発症した。右冠動脈および左冠動脈前下行枝に冠動脈ステントを留置した。ソラフェニブを中止しtemsirolimus投与を開始したが、副作用のため中止となり、その後緩和治療へ移行した。

Sorafenib is a tyrosine kinase inhibitor (TKI) of the vascular endothelial growth factor receptor (VEGFR) used for advanced renal cell carcinoma. Treatment with sorafenib prolongs progression-free survival in patients with advanced clear-cell renal cell carcinoma. However, in spite of its therapeutic efficacy, sorafenib causes a wide range of adverse events. Cardiovascular adverse events have been observed when sorafenib was used with targeted agents. Although these adverse events like hypertension, reduced left ventricular ejection fraction, cardiac ischemia or infarction were manageable with standard medical therapies in most cases, some had a poor clinical outcome. We report three cases of acute myocardial infarction associated with sorafenib in patients with metastatic renal cell carcinoma.

OBJECTIVES: Docetaxel is used as the first-line chemotherapy for castration-resistant prostate cancer (CRPC), but docetaxel resistance occurs in part owing to induction of P-glycoprotein (P-gp) encoded by multidrug resistance protein 1 (MDR1) gene. A recently developed taxane-cabazitaxel-has poor affinity for P-gp and is thereby effective in docetaxel-resistant CRPC. It has been recently demonstrated that exosomes in the body fluids could serve as a diagnostic marker because they contain proteins and RNAs specific to the cells from which they are derived. In this study, we aimed to investigate if P-gp in blood exosomes could be a marker to diagnose docetaxel resistance and select a taxoid for patients with CRPC. METHODS AND MATERIALS: Exosomes were isolated by differential centrifugation from docetaxel-resistant prostate cancer (PC-3) cells (PC-3R) and their parental PC-3 cells and from the serum of patients. Silencing of P-gp was performed by small interfering RNA transfection. Protein expression was examined by Western blot analysis. Viability of cells treated with docetaxel or cabazitaxel was determined by water soluble tetrazolium salt (WST) assay. RESULTS: The level of P-gp was higher in exosomes as well as cell lysates from PC-3R cells than in those from PC-3 cells. Cabazitaxel effectively killed PC-3R cells, and MDR1 knockdown improved the sensitivity of PC-3R cells to docetaxel but not to cabazitaxel. The P-gp level in blood exosomes was relatively higher in clinically docetaxel-resistant patients than in therapy-naïve patients. CONCLUSIONS: Our results suggest that detection of P-gp in blood exosomes, which is involved in resistance to docetaxel but not to cabazitaxel, could be useful to diagnose docetaxel resistance and select an appropriate taxoid for patients with CRPC-docetaxel or cabazitaxel.