Wenbin Song

Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis

The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down‐regulation of the c‐Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer.

The Expression and Evaluation of Androgen Receptor in Human Renal Cell Carcinoma

OBJECTIVE To investigate the expression of androgen receptor (AR) with clinical and pathologic features in patients with renal cell carcinoma (RCC) and to explore the function of AR using human RCC cells. MATERIALS AND METHODS The expression of AR was detected by immunohistochemistry in 44 adjacent normal kidney tissues of 120 RCC patients and also in 16 metastatic RCC patients with their respective primary and metastatic tissue samples. The expression of AR was examined by western blot in commonly used human RCC cell lines and normal kidney epithelial cells, and the luciferase assay was performed in those AR-positive RCC cells. RESULTS The expression rate of AR was higher in adjacent normal kidney (90.9%) than in RCC tissues (30.0%, P <.001), and it was negatively associated with pT stage and Fuhrmans grade. Specifically, there were 40.7% AR-positive cases in pT1 compared with 8.0% in pT3 (P = .013), and 50.0% of grade I cases were found to be AR positive compared with 12.9% in grade III (P = .008). AR expression was slightly higher in primary RCC tissues (12.5%) than their respective metastases (0%, P = .484). AR strongly expressed in CAKI-2 and OSRC-2 cells with little transactivation, which might indicate that AR in those 2 RCC cells has little function. CONCLUSION Our results suggest that any attempt to investigate the roles of AR in RCC progression might need to combine the detection of AR expression in tissue samples with examining its function to make a correct correlation between AR and RCC progression.

Replication and Fine Mapping for Association of the C2orf43, FOXP4, GPRC6A and RFX6 Genes with Prostate Cancer in the Chinese Population

Background Prostate cancer represents the leading cause of male death across the world. A recent genome-wide association study (GWAS) identified five novel susceptibility loci for prostate cancer in the Japanese population. This study is to replicate and fine map the potential association of these five loci with prostate cancer in the Chinese Han population. Methods In Phase I of the study, we tested the five single nucleotide polymorphisms (SNPs) which showed the strongest association evidence in the original GWAS in Japanese. The study sample consists of 1,169 Chinese Hans, comprising 483 patients and 686 healthy controls. Then in phase II, flanking SNPs of the successfully replicated SNPs in Phase I were genotyped and tested for association with prostate cancer to fine map those significant association signals. Results We successfully replicated the association of rs13385191 (located in the C2orf43 gene, P = 8.60×10−5), rs12653946 (P = 1.33×10−6), rs1983891 (FOXP4, P = 6.22×10−5), and rs339331 (GPRC6A/RFX6, P = 1.42×10−5) with prostate cancer. The most significant odds ratio (OR) was recorded as 1.41 (95% confidence interval 1.18–1.68) for rs12653946. Rs9600079 did not show significant association (P = 8.07×10−2) with prostate cancer in this study. The Phase II study refined these association signals, and identified several SNPs showing more significant association with prostate cancer than the very SNPs tested in Phase I. Conclusions Our results provide further support for association of the C2orf43, FOXP4, GPRC6A and RFX6 genes with prostate cancer in Eastern Asian populations. This study also characterized the novel loci reported in the original GWAS with more details. Further work is still required to determine the functional variations and finally clarify the underlying biological mechanisms.

Kaempferol induces cell cycle arrest and apoptosis in renal cell carcinoma through EGFR/p38 signaling.

Kaempferol has been shown to inhibit cell growth, induce apoptosis and cell cycle arrest in several tumors, but not in renal cell carcinoma (RCC). In the present study, we investigated the effects of kaempferol and the underlying mechanism(s) on the cell growth of RCC cells. MTT assay and colony formation assay were used to study cell growth, and flow cytometry was used to study apoptosis and cell cycles in different RCC cells treated with various doses of kaempferol. A significant inhibition on cell growth, induction of apoptosis and cell cycle arrest were observed in 786-O and 769-P cells after kaempferol treatment compared with the control group. Moreover, the results clearly showed that kaempferol causes a strong inhibition of the activation of the EGFR/p38 signaling pathways, upregulation of p21 expression and downregulation of cyclin B1 expression in human RCC cells, together with activation of PARP cleavages, induction of apoptotic death and inhibition of cell growth. Collectively, our results suggest that kaempferol may serve as a candidate for chemo-preventive or chemotherapeutic agents for RCC.

Overexpression of FABP7 promotes cell growth and predicts poor prognosis of clear cell renal cell carcinoma

OBJECTIVES Renal cell carcinoma (RCC) is one of the most lethal urologic malignancies; however, the molecular events supporting RCC carcinogenesis remain poorly understood. The aim of the present study was to determine the differential expression of genes between normal kidney and clear cell RCC (ccRCC) samples and investigate the biological function of the most frequently altered gene in RCC cells. MATERIALS AND METHODS The gene expression profiles of 60 ccRCC and matched normal kidney samples from The Cancer Genome Atlas were analyzed. The altered genes were subjected to functional annotation clustering and integrative pathway analysis. The expression of one of the most frequently altered gene, fatty acid-binding protein (FABP) 7, in ccRCC and matched normal kidney samples was verified by immunohistochemistry and the association between FABP7 level and patient survival was investigated. Furthermore, FABP7 DNA copy number alteration, methylation, and mutation status in ccRCC from The Cancer Genome Atlas were analyzed. Finally, FABP7-overexpressing RCC cells were generated to determine the function of FABP7 in cell growth and the potential mechanisms of action. RESULTS FABP7 was significantly up-regulated in ccRCC, and the expression of FABP7 positively correlated with advanced clinical stage and poor survival of patients with ccRCC. FABP7 DNA copy number alteration was not frequently detected in ccRCC, and no mutation of FABP7 was found. FABP7 messenger RNA expression inversely correlated with its DNA methylation. Overexpression of FABP7 in RCC cells enhanced cell growth, clonogenicity, cell cycle progression and activated both extracellular-signal-regulated kinases (ERK) and signal transducer and activator of transcription 3 (Stat3) signaling. CONCLUSION FABP7 is overexpressed in ccRCC and promotes cell growth by the activation of ERK and Stat3 signaling pathways. Evidence from the clinical observations and experimental data suggests that FABP7 is a novel prognostic marker and potential therapeutic target for ccRCC.

Reciprocal regulation of hypoxia-inducible factor 2α and GLI1 expression associated with the radioresistance of renal cell carcinoma.

PURPOSE Renal cell carcinoma (RCC) is often considered a radioresistant tumor, but the molecular mechanism underlying its radioresistance is poorly understood. This study explored the roles of hypoxia-inducible factor 2α (HIF2α) and sonic hedgehog (SHH)-GLI1 signaling in mediating the radioresistance of RCC cells and to unveil the interaction between these 2 signaling pathways. METHODS AND MATERIALS The activities of SHH-GLI1 signaling pathway under normoxia and hypoxia in RCC cells were examined by real-time polymerase chain reaction, Western blot, and luciferase reporter assay. The expression of HIF2α and GLI1 in RCC patients was examined by immunohistochemistry, and their correlation was analyzed. Furthermore, RCC cells were treated with HIF2α-specific shRNA (sh-HIF2α), GLI1 inhibitor GANT61, or a combination to determine the effect of ionizing radiation (IR) on RCC cells based on clonogenic assay and double-strand break repair assay. RESULTS RCC cells exhibited elevated SHH-GLI1 activities under hypoxia, which was mediated by HIF2α. Hypoxia induced GLI1 activation through SMO-independent pathways that could be ablated by PI3K inhibitor or MEK inhibitor. Remarkably, the SHH-GLI1 pathway also upregulated HIF2α expression in normoxia. Apparently, there was a positive correlation between HIF2α and GLI1 expression in RCC patients. The combination of sh-HIF2α and GLI1 inhibitor significantly sensitized RCC cells to IR. CONCLUSIONS Cross-talk between the HIF2α and SHH-GLI1 pathways was demonstrated in RCC. Cotargeting these 2 pathways, significantly sensitizing RCC cells to IR, provides a novel strategy for RCC treatment.

Priapism as the Initial Manifestation of a Penile and Lower Limb Cutaneous Metastasis of Prostate Adenocarcinoma With Low Serum PSA Level

Penile and/or cutaneous metastases from prostate adenocarcinoma rarely occur. Here, we detail the case of a 78-year-old man suffering from priapism caused by metastatic prostate cancer with both penile and lower limb cutaneous spread. His serum prostate-specific antigen level was 0.09 μg/L when priapism developed. Corpora cavernosa biopsy was refused by the patient and radical penectomy was performed. Postoperative pathologic and immunohistochemical studies revealed undifferentiated prostate adenocarcinoma cells growing in corpora cavernosa. Two months later, the patient presented with multiple, erythematous nodules over the right lower leg. The prostate-specific antigen level was found to be 0.264 μg/L. Biopsy of a skin nodule revealed neoplastic cells consistent with metastatic prostate adenocarcinoma. This is the first known case of metastatic prostate cancer found in both penis and skin with a low serum prostate-specific antigen level. Priapism presented as the initial clinical manifestation of metastatic prostate cancer.

Infiltrating neutrophils promote renal cell carcinoma (RCC) proliferation via modulating androgen receptor (AR) → c-Myc signals

Early studies found critical roles for neutrophils in renal cell carcinoma (RCC) progression. However, detailed mechanisms of how infiltrating neutrophils in the kidney tumor microenvironment impact RCC progression remain unclear. Here we found more neutrophils were infiltrated in human RCC lesions than those found in surrounding normal kidney tissues. Similarly, in vitro studies also revealed that RCC cells recruited more neutrophil HL-60N cells than normal kidney epithelial cells. Furthermore, in vitro and in vivo experiments also showed that the infiltrated neutrophils could promote RCC cell growth. Mechanism studies showed that co-culture of RCC cells with neutrophil HL-60N cells could selectively upregulate the androgen receptor (AR) signals, which might then alter the c-Myc signals. Interruption approaches using AR-siRNA to knock down AR in RCC cells blocked neutrophil-enhanced RCC cell proliferation. In vivo data using an orthotopically xenografted RCC mouse model also confirmed that infiltrated neutrophils could promote RCC proliferation via modulating the expressions of related cytokines. Together, these results conclude that infiltrated neutrophils may function through modulating the AR → c-Myc signals to promote RCC cell proliferation. Targeting this newly identified infiltrating neutrophil → AR → c-Myc signal pathway in the kidney tumor microenvironment may provide a new potential therapy to better suppress RCC progression.

The Retroperitoneal Laparoscopic Renal Capsulectomy for Spontaneous Renal Subcapsular Fluid Collection: A Case-Series Report and Literature Review.

AbstractSpontaneous renal subcapsular fluid collection may occur as a rare presentation of nephritic syndrome, and distension of the renal capsula and Gerota fascia due to massive fluid accumulation may cause pain. In addition, hypertension secondary to renal ischemia and activation of renin–angiotensin–aldosterone system may also occur. The objective of this study is to evaluate the surgical outcome of retroperitoneal laparoscopic renal capsulectomy for patients with this disease.We retrospectively analyzed the clinical data of 10 female patients with spontaneous renal subcapsular fluid collection, diagnosed with B ultrasound and enhanced computed tomography (CT) scan. Eight patients first underwent percutaneous renal subcapsular drainage, which seemed to be less effective, and then all patients underwent retroperitoneal laparoscopic renal capsulectomy. The volume of renal subcapsular fluid was documented, the fluid was examined by routine biochemical tests, and the excised renal capsules underwent pathological examination individually. The postoperative drainage time for each patient was documented, and follow-up was conducted 1, 3, 6, 12 months, and 2 years postoperatively.Retroperitoneal laparoscopic renal capsulectomy was successfully performed in all patients with no major complications. The average volume of renal subcapsular fluid was 436 milliliter (mL, 180–880 mL) in light yellow color, and the concentration of creatinine and urea nitrogen was quite similar to that of serum. The pathological findings revealed fibrous dysplasia of the renal capsule with chronic infiltration of inflammatory cells. The average drainage time was 11.5 days (5–30 days) postoperatively. All patients recovered 1 month after the operation and there were no recurrences with a mean follow-up period of 12 months (6–24 months).The reason for spontaneous renal subcapsular fluid collection is unknown, and the aim of treatment is mainly to alleviate symptoms. In our experience, retroperitoneal laparoscopic renal capsulectomy is an effective surgical treatment, especially for patients who were refractory to percutaneous renal subcapsular drainage, with no observed recurrence.

Targeting newly identified ERβ/TGFβ‐1/SMAD3 signals with the FDA‐approved antiestrogen Faslodex or an ERβ selective antagonist in renal cell carcinoma

Renal cell carcinoma (RCC) has the third highest mortality rate among urological tumors, and 20–30% of RCC patients present with metastatic RCC at the time of diagnosis. Although recent studies have indicated that estrogen receptor β (ERβ) could play promoting roles in RCC progression, the detailed mechanisms remain to be clarified. In the present study, we found that expression of ERβ, but not ERα, increases with tumor stage and grade, and also observed that modification of ERβ signals using estrogens/anti‐estrogens, shRNA knockdown of ERβ and overexpression of ERβ using ectopic cDNA affects RCC cell proliferation, migration and invasion. Mechanism analysis revealed that ERβ can promote RCC cell invasion via an increase in transforming growth factor β1 (TGF‐β1)/SMAD3 signals, and interrupting TGF‐β1/SMAD3 signals with a TGFβR1 inhibitor can reverse/block ERβ‐increased RCC cell migration. Importantly, preclinical analyses using in vivo mouse models of RCC revealed that targeting of this newly identified ERβ/TGF‐β1/SMAD3 pathway with either the FDA‐approved anti‐estrogen ICI182,780 (Faslodex) or a selective ERβ antagonist 4‐[2‐phenyl‐5,7 bis(trifluoromethyl)pyrazolo[1,5‐a]pyrimidin‐3‐yl]phenol can significantly reduce RCC tumor growth and invasion, which may be suitable as the basis for novel therapies to more effectively suppress metastatic RCC.