KIF2C promotes clear cell renal cell carcinoma progression via activating JAK2/STAT3 signaling pathway

KIF2C promotes paclitaxel resistance by depolymerizing polyglutamylated microtubules

The long-term effectiveness of paclitaxel is limited by chemoresistance. In this study, we elucidate the molecular mechanism by which kinesin family member 2C (KIF2C), a well-known microtubule depolymerase, contributes to the development of chemoresistance in triple-negative breast cancer (TNBC). We observed elevated levels of KIF2C, tubulin tyrosination, and polyglutamylation in human and mouse breast cancer cells resistant to paclitaxel. Additionally, these chemoresistant cells possessed cross-resistance to diverse microtubule-targeting agents (MTAs). We demonstrated that KIF2C preferentially depolymerizes polyglutamylated tubulin, even in the presence of paclitaxel. To counter this, we developed 7S9, a chemical inhibitor of KIF2C, that prohibits the dissociation of KIF2C from microtubules. The combination of 7S9 and paclitaxel significantly reduced tumorigenesis in chemoresistant TNBC model in mice. Moreover, 7S9 diminished cancer cell chemoresistance to several clinically available MTAs. Our findings elucidate the molecular mechanism of KIF2C-mediated chemoresistance and highlight KIF2C as a promising target for combating cross-resistance in TNBC.

Overexpression of KIF2C amplifies tamoxifen resistance and lung metastasis of breast cancer through PLK1/C-Myc pathway

We highlighted the importance of KIF2C in the development of resistance to tamoxifen and its role in promoting lung metastasis in breast cancer, as well as the mechanisms that underpin these processes. KIF2C overexpression and knockdown lentiviruses were transfected into MCF-7 and MCF-7/TAM cells. A nude mouse model of MCF-7/TAM tumors and lung metastasis was established. The PLK1 inhibitor BI2536 was used to explore the underlying mechanism. KIF2C is elevated in tamoxifen-resistant breast cancer. KIF2C knockdown MCF7/TAM cells show increased sensitivity to tamoxifen, indicated by fewer cell clones, invasive cells, migration area, and lumen count, as well as a higher rate of cell apoptosis. KIF2C is linked to the PLK1/c-Myc signaling pathway, and BI2536 inhibits its enhancement of tamoxifen resistance. Results from an in situ experiment on breast cancer in mice are consistent with in vitro findings. KIF2C upregulation is linked to greater tamoxifen resistance in breast cancer, facilitating progression and lung metastasis in resistant cases. KIF2C's potential mechanism of action is linked to the PLK1/c-Myc signaling pathway.

RNF19A inhibits bladder cancer progression by regulating ILK ubiquitination and inactivating the AKT/mTOR signalling pathway

BACKGROUND

The role of the RING finger protein superfamily in carcinogenesis has been widely studied, but one member of this family, RNF19A, has not yet been thoroughly explored in bladder cancer (BCa).

METHODS

The expression levels of RNF19A in BCa samples and cell lines were analysed through data mining of public resources and further experiments. BCa cells in which RNF19A was stably overexpressed or knocked down were generated through lentivirus infection. The effects of RNF19A on cell proliferation, migration, and invasion were explored by performing a series of in vitro experiments, including CCK-8, colony formation, wound healing, and Transwell invasion assays. Using bioinformatics methods and multiple experiments, including western blot, qRT‒PCR, immunoprecipitation, cycloheximide, ubiquitination, and rescue assays, the mechanism underlying the effect of RNF19A on the progression of BCa was investigated.

RESULTS

Here, we found that RNF19A expression was reduced in BCa samples and cell lines and that lower RNF19A expression predicted shorter overall survival of BCa patients. Functionally, forced expression of RNF19A suppressed BCa cell proliferation, migration, and invasion by inactivating the AKT/mTOR signalling pathway, whereas silencing RNF19A had the opposite effects. Mechanistically, RNF19A could directly interact with ILK and promote its ubiquitination and degradation. Rescue experiments revealed that forced ILK expression partially rescued the decreased phosphorylation of AKT, mTOR, and S6K1 caused by RNF19A overexpression and that the increased levels of the p-AKT, p-mTOR, and p-S6K1 proteins induced by RNF19A knockdown were eliminated after silencing ILK. Similarly, the effects of RNF19A overexpression or knockdown on the phenotypes of cell proliferation, migration, and invasion could also be restored by forced or decreased ILK expression.

CONCLUSIONS

RNF19A suppressed the proliferation, migration, and invasion abilities of BCa cells by regulating ILK ubiquitination and inactivating the AKT/mTOR signalling pathway. RNF19A might be a potential prognostic biomarker and promising therapeutic target for BCa.

Overexpression of cyclin F/CCNF as an independent prognostic factor for poor survival in clear cell renal cell carcinoma

Cyclin F (encoded by CCNF gene) has been reported to be implicated in the pathobiology of several human cancers. However, its potential clinical significance in clear cell renal cell carcinoma (ccRCC) remains unknown. The present study aimed to evaluate the potential significance of cyclin F, assessed by immunohistochemical (IHC) staining and molecular (bioinformatics) techniques, as a prognostic marker in ccRCC in relation to clinicopathological features and outcomes. IHC staining was performed using two independent ccRCC tissue array cohorts, herein called tissue macroarray (TMA)_1 and tissue microarray (TMA)_2, composed of 108 ccRCCs and 37 histologically normal tissues adjacent to the tumor (NAT) and 192 ccRCCs and 16 normal kidney samples, respectively. The mRNA expression data were obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) public datasets, followed by bioinformatics analysis of biological mechanisms underlying prognosis. The relationship between immune cell infiltration level and CCNF expression in ccRCC was investigated using the Tumor Immune Estimation Resource 2.0 (TIMER2) and Gene Expression Profiling Interactive Analysis 2 (GEPIA2). Cyclin F expression was significantly elevated in ccRCC lesions compared to both NAT and normal renal tissues. Likewise, CCNF mRNA was markedly increased in ccRCCs relative to non-cancerous tissues. In all analyzed cohorts, tumors with features of more aggressive behavior were more likely to display cyclin F/CCNF-high expression than low. Furthermore, patients with high cyclin F/CCNF expression had shorter overall survival (OS) times than those with low expression. In addition, multivariable analysis revealed that cyclin F/CCNF-high expression was an independent prognostic factor for poor OS in ccRCC. Enrichment analysis for mechanistically relevant processes showed that CCNF and its highly correlated genes initiate the signaling pathways that eventually result in uncontrolled cell proliferation. CCNF expression was also correlated with immune cell infiltration and caused poor outcomes depending on the abundance of tumor-infiltrating immune cells in ccRCC. Our findings suggest that cyclin F/CCNF expression is likely to have an essential role in ccRCC pathobiology through regulating multiple oncogenic signaling pathways and affecting the tumor immune microenvironment and may serve as prognostic biomarker and promising therapeutic target in ccRCC.

KIF2C: An important factor involved in signaling pathways, immune infiltration, and DNA damage repair in tumorigenesis

BACKGROUNDS

Poorly regulated mitosis and chromosomal instability are common characteristics in malignant tumor cells. Kinesin family member 2 C (KIF2C), also known as mitotic centromere-associated kinesin (MCAK) is an essential component during mitotic regulation. In recent years, KIF2C was shown to be dysregulated in several tumors and was involved in many aspects of tumor self-regulation. Research on KIF2C may be a new direction and target for anti-tumor therapy.

OBJECT

The article aims at reviewing current literatures and summarizing the research status of KIF2C in malignant tumors as well as the oncogenic signaling pathways associated with KIF2C and its role in immune infiltration.

RESULT

In this review, we summarize the KIF2C mechanisms and signaling pathways in different malignant tumors, and briefly describe its involvement in pathways related to classical chemotherapeutic drug resistance, such as MEK/ERK, mTOR, Wnt/β-catenin, P53 and TGF-β1/Smad pathways. KIF2C upregulation was shown to promote tumor cell migration, invasion, chemotherapy resistance and inhibit DNA damage repair. It was also highly correlated with microRNAs, and CD4 +T cell and CD8 +T cell tumor immune infiltration.

CONCLUSION

This review shows that KIF2C may function as a new anticancer drug target with great potential for malignant tumor treatment and the mitigation of chemotherapy resistance.