Gαi1 Promoted Proliferation, Migration and Invasion via Activating the Akt-mTOR/Erk-MAPK Signaling Pathway in Renal Cell Carcinoma

Pterostilbene and 6-shogaol exhibit inhibitory effects on sunitinib resistance and motility by suppressing the RLIP76-initiated Ras/ERK and Akt/mTOR pathways in renal cancer cells

Sunitinib (SUN) is the first-line targeted therapeutic drug for advanced renal cell carcinoma (RCC). However, SUN resistance is frequently observed to result in tumor metastasis, with a poor survival rate. Therefore, finding an effective and safe adjuvant to reduce drug resistance is important for RCC treatment. Pterostilbene (PTE) and 6-shogaol (6-S) are natural phytochemicals found in edible sources and have potential applications against various cancers. However, the biological mechanisms of PTE and 6-S in SUN-resistant RCC are still unclear. Accordingly, this study investigated the regulatory effects of PTE and 6-S on cell survival, drug resistance, and cell invasion in 786-O and SUN-resistant 786-O (786-O SUNR) cells, respectively. The results demonstrated that PTE and 6-S induced apoptosis in both cell lines by upregulating the Bax/Bcl-2 ratio. Additionally, PTE and 6-S increased SUN sensitivity by inhibiting the expression of the RLIP76 transport protein, reduced cell invasion and downregulated MMP expression in both 786-O and 786-O SUNR cells. Mechanistically, PTE, and 6-S significantly and dose-dependently suppressed the RLIP76-initiated Ras/ERK and Akt/mTOR pathways. In summary, PTE and 6-S induce apoptosis, enhance SUN sensitivity, and inhibit migration in both 786-O and 786-O SUNR cells. These novel findings demonstrate the potential of PTE and 6-S as target therapeutic adjuvants for RCC treatment.

Smoking enhanced the expression of c-kit in chromophobe renal cell carcinoma

INTRODUCTION

Smoking is an important risk factor for inducing renal cell carcinoma (RCC), but its specific mechanism affecting the development of RCC remains to be elucidated. Chromophobe RCC (ChRCC) is a subtype of RCC. Many studies have shown smoking is closely associated with RCC occurrence and c-kit plays a critical role in the progression of RCC, however, few studies focus on ChRCC. This study investigated the molecular mechanism between smoking and the c-kit pathway in ChRCC.

METHODS

Differentially expressed genes (DEGs) were obtained from The Cancer Genome Atlas (TCGA) in ChRCC and the expression of KIT in ChRCC was analyzed through the TCGA database combined with Gene Expression Omnibus (GEO) and oncomine databases. Moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and Protein Protein Interaction (PPI) network analysis were performed to explore the function of KIT and correlated DEGs as well as its co-expression genes in ChRCC. Finally, ChRCC patient samples were used to verify the effect of smoking on the c-kit expression.

RESULTS

The results showed that KIT is one of the DEGs and plays a vital role in ChRCC tumorigenesis. Interestingly, the expression of c-kit in cancer tissues of 27 smoking patients was significantly higher than that of 25 non-smoking patients (p<0.05), which suggests smoking might enhance the expression of c-kit in ChRCC patients.

CONCLUSIONS

Our results demonstrate that smoking might play a pivotal role in the ChRCC tumorigenesis via a pathway related to c-kit, and provided new insight into the relationship between smoking and the c-kit pathway in ChRCC.

Radix Actinidia chinensis Suppresses Renal Cell Carcinoma Progression: Network Pharmacology Prediction and In Vivo Experimental Validation

Background

Renal cell carcinoma (RCC) is a frequent disease with limited curative methods. This study is aimed at investigating the role and mechanism of Radix Actinidia chinensis (RAC) on RCC.

Methods

The ingredients, target, and crucial pathways of RAC in RCC therapy were analyzed by network pharmacology. Then, an RCC animal model was established by subcutaneously injecting A498 cell suspension to BALB/c nude mice. After 1 week, the mice in the RAC-L/M/H groups were administered with RAC at 5, 10, and 20 mg/kg/d, respectively. The histopathology of the tumor was evaluated. The contents of tumor inflammatory cytokines and serum oxidative stress factors were detected by ELISA. The apoptosis of tumor tissues was assessed by TUNEL staining. The expressions of apoptosis-, proliferate-, autophagy-, and MAPK-related proteins were measured.

Results

There were 13 active ingredients, and 20 RCC-relevant targets were selected from RAC; KEGG pathway indicated that these targets were enriched in the PI3K/AKT/mTOR and MAPK pathway. In in vivo experiments, RAC not only obviously damaged tumor cells and decreased the release of inflammatory cytokines and oxidative stress factors but also enhanced the apoptosis of the tumor cell in RCC mice. Besides, the expressions of apoptosis-, proliferate-, autophagy-, PI3K/AKT/mTOR path-, and MAPK path-related proteins were all affected by RAC.

Conclusion

RAC attenuated RCC by regulating inflammation response, oxidative stress, apoptosis, proliferation, and autophagy, and its effects were partly linked to the PI3K/AKT/mTOR and MAPK pathway, which indicated that RAC may be a candidate drug for RCC.