Treatment of metastatic renal cell carcinoma and renal pelvic cancer

Fisetin enhances cisplatin sensitivity in renal cell carcinoma via the CDK6/PI3K/Akt/mTOR signaling pathway

Cisplatin resistance is ubiquitous among patients with renal cell carcinoma (RCC). The present study assessed the role of fisetin in regulating cisplatin sensitivity and increasing the efficacy of chemotherapy for patients with RCC. Cell Counting Kit-8 and colony formation assays were used to assess the proliferation of RCC cells after fisetin and cisplatin treatment. The mRNA expression levels of cyclin-dependent kinase (CDK)6 were evaluated using reverse transcription-quantitative PCR. The expression levels of CDK6 and key proteins of the PI3K/Akt/mTOR signaling pathway were assessed using western blotting. The present study demonstrated that fisetin inhibited the proliferation and colony-forming ability of RCC cells, and induced apoptosis and cell cycle arrest in a dose-dependent manner. Additionally, fisetin enhanced the antineoplastic effects of cisplatin, as demonstrated by the increase in proliferation inhibition and apoptosis promotion after fisetin and cisplatin combination treatment. Furthermore, fisetin regulated the PI3K/Akt/mTOR signaling pathway through CDK6 inhibition, which enhanced cisplatin sensitivity. Overexpression of CDK6 neutralized the positive effects of fisetin on the improvement of cisplatin sensitivity in RCC cells. In conclusion, fisetin may enhance the sensitivity of RCC cells to cisplatin via the CDK6/PI3K/Akt/mTOR signaling pathway.

Dynamic Predictive Models with Visualized Machine Learning for Assessing the Risk of Lung Metastasis in Kidney Cancer Patients

OBJECTIVE

To establish and verify the clinical prediction model of lung metastasis in renal cancer patients.

METHOD

Kidney cancer patients from January 1, 2010, to December 31, 2017, in the SEER database were enrolled in this study. In the first section, LASSO method was adopted to select variables. Independent influencing factors were identified after multivariate logistic regression analysis. In the second section, machine learning (ML) algorithms were implemented to establish models and 10-foldcross-validation was used to train the models. Finally, receiver operating characteristic curves, probability density functions, and clinical utility curve were applied to estimate model's performance. The final model was shown by a website calculator.

RESULT

Lung metastasis was confirmed in 7.43% (3171 out of 42650) of study population. In multivariate logistic regression, bone metastasis, brain metastasis, grade, liver metastasis, N stage, T stage, and tumor size were independent risk factors of lung metastasis in renal cancer patients. Primary site and sequence number were independent protection factors of LM in renal cancer patients. The above 9 impact factors were used to develop the prediction models, which included random forest (RF), naive Bayes classifier (NBC), decision tree (DT), xgboost (XGB), gradient boosting machine (GBM), and logistic regression (LR). In 10-foldcross-validation, the average area under curve (AUC) ranked from 0.907 to 0.934. In ROC curve analysis, AUC ranged from 0.879-0.922. We found that the XGB model performed best, and a Web-based calculator was done according to XGB model.

CONCLUSION

This study provided preliminary evidence that the ML algorithm can be used to predict lung metastases in patients with kidney cancer. This low cost, noninvasive and easy to implement diagnostic method is useful for clinical work. Of course this model still needs to undergo more real-world validation.

Lefty A is involved in sunitinib resistance of renal cell carcinoma cells via regulation of IL-8

Renal cell carcinoma (RCC) is the third most frequent malignancy within urological oncology. Sunitinib has been used as the standard of treatment for first-line RCC therapy. Understanding mechanisms of sunitinib resistance in RCC cell is important for clinical therapy and drug development. We established sunitinib resistant RCC cells by treating cells with increasing concentrations of sunitinib and named resistant cells as RCC/SR. Lefty A, an important embryonic morphogen, was increased in RCC/SR cells. Targeted inhibition of Lefty via its siRNAs restored the sensitivity of renal resistant cells to sunitinib treatment. It was due to that si-Lefty can decrease the expression of interleukin-8 (IL-8) in RCC/SR cells. Knockdown of IL-8 abolished Lefty-regulated sunitinib sensitivity of RCC cells. Mechanistically, Lefty can regulate IL-8 transcription via activation of p65, one major transcription factor of IL-8. Collectively, our present revealed that Lefty A can regulate sunitinib sensitivity of RCC cells of via NF-κB/IL-8 signals. It indicated that targeted inhibition of Lefty might be a potent approach to overcome sunitinib resistance of RCC.

TBOPP enhances the anticancer effect of cisplatin by inhibiting DOCK1 in renal cell carcinoma

The treatment of renal cell carcinoma (RCC) with chemotherapy remains a challenge; therefore, improving the knowledge of the molecular mechanisms underlying RCC chemoresistance and developing novel therapeutic strategies is important. Dedicator of cytokinesis 1 (DOCK1), the first member of the DOCK family to be discovered, displays various roles during tumorigenesis; however, its role during RCC progression is not completely understood. Therefore, the present study aimed to clarify the function of DOCK1 and 1‑[2‑(3'‑(trifluoromethyl)‑(1,1'‑biphenyl)‑4‑yl)‑2‑oxoethyl]‑5‑pyrrolidinylsulfonyl‑2 (1H)‑pyridone (TBOPP), a DOCK1‑sensitive inhibitor, during RCC development and chemoresistance. The results of CCK‑8 and EdU assay indicated that TBOPP decreased RCC cell viability and proliferation compared with the control group, and sensitized RCC cells to cisplatin. Moreover, RCC cells with high DOCK1 expression levels displayed increased resistance to cisplatin, whereas DOCK1 knockdown enhanced the lethal effects of cisplatin on RCC cells. Furthermore, the results determined by western blotting, CCK‑8 and cell apoptosis assay indicated that TBOPP effectively reduced DOCK1 expression levels compared with the control group, and the TBOPP‑mediated cisplatin sensitizing effect was mediated by DOCK1 inhibition. The present study suggests that DOCK1 plays a vital role in RCC cell chemoresistance to cisplatin; therefore, TBOPP may serve as a novel therapeutic agent for RCC chemoresistance.

Sperm-associated antigen 4, a novel hypoxia-inducible factor 1 target, regulates cytokinesis, and its expression correlates with the prognosis of renal cell carcinoma

Hypoxia plays a crucial role in many pathophysiological conditions, including cancer biology, and hypoxia-inducible factor (HIF) regulates transcriptional responses under hypoxia. To elucidate the cellular responses to hypoxia, we performed chromatin immunoprecipitation with deep sequencing in combination with microarray analysis and identified HIF-1 targets. We focused on one of the novel targets, sperm-associated antigen 4 (SPAG4), whose function was unknown. SPAG4, an HIF-1-specific target, is up-regulated in various cultured cells under hypoxia. Examination of SPAG4 expression using a tissue microarray consisting of 190 human renal cell carcinoma (RCC) samples revealed that SPAG4 is an independent prognostic factor of cancer-specific mortality. Live-cell imaging revealed localization of SPAG4 at the intercellular bridge in telophase. We also studied cells in which SPAG4 was knocked down. Hypoxia enhances tetraploidy, which disturbs cell proliferation, and knockdown of SPAG4 increased tetraploid formation and decreased cell proliferation under both normoxic and hypoxic conditions. Studies using deletion mutants of SPAG4 also suggested the involvement of SPAG4 in cytokinesis. Microarray analysis confirmed dysregulation of cytokinesis-related genes by knockdown of SPAG4. In conclusion, SPAG4 is an independent prognostic factor in RCC and plays a crucial role in cytokinesis to defend against hypoxia-induced tetraploid formation. This defensive mechanism may promote survival of cancer cells under hypoxic conditions, thus leading to poor prognosis.

Endothelial follicle stimulating hormone receptor in primary kidney cancer correlates with subsequent response to sunitinib

Sunitinib is an anti-angiogenic receptor tyrosine kinase inhibitor used to treat advanced metastatic renal cell carcinoma and other types of cancer. Sutent is effective in only approximately 70% of clear cell renal cell carcinoma (CCRCC) patients, has significant adverse side effects and no method is available to predict which patients will not respond. Our purpose was to explore the possibility of introducing an effective prediction method based on a marker of the tumour vasculature, the follicle stimulating hormone receptor (FSHR). Fifty patients diagnosed with advanced metastatic CCRCC have been subjected to surgery for removal of the primary tumour and were subsequently treated with sunitinib. After three months of therapy the patients were categorized as 'responsive', 'stable' or 'non-responsive' based on the RECIST guidelines. The blood vessel density and the percentage of FSHR-positive vessels were determined by immunofluorescence on sections from the primary tumours removed by surgery, prior to the sunitinib treatment. The percentage of FSHR-stained vessels was on average fivefold higher for the patients who responded to the treatment in comparison with the stable group and almost eightfold higher than in the non-responsive group. The percentage allowed the detection of responders with 87-100% sensitivity and specificity. No significant differences were detected in the total density of vessels among the three groups. The data suggest that FSHR expression levels in the blood vessels of CCRCC primary tumours can be used to predict, with high sensitivity and specificity, the patients who will respond to sunitinib therapy.

Serum markers of apoptosis in the early period of heart transplantation

CONTEXT AND OBJECTIVE

To assess the relationship between levels of serum markers of apoptosis and rejection grades in heart transplant (HTx).

MATERIALS AND METHODS

A prospective study was conducted in 91 HTx. We correlated apoptosis markers and biopsy samples. The apoptosis markers were: TRAIL, TRAIL-R1, TRAIL-R2, TRAIL-R3, TRAIL-R4, sFas, sTNF-R1 and sTNF-R2.

RESULTS

The only significant correlation with rejection grade was sFas (r=0.329; p=0.005). Cyclosporine showed a proapoptotic effect (sTNF-R1 0.02 and sTNF-R2 0.02) and everolimus an antiapoptotic effect (sTNF-R1 r= -0.523; p=0.0001 and sTNF-R2 r= -0.405; p=0.0001).

CONCLUSIONS

The utility of specific apoptosis markers in peripheral blood for diagnosis of acute cellular rejection is low. Everolimus may have an anti-apoptotic effect.