Smac combined with DDP can inhibit drug resistance of ovarian cancer through regulation of Survivin expression

Upregulation of TIMM8A is correlated with prognosis and immune regulation in BC

Backgrounds

Breast cancer is a common malignant tumors in women. TIMM8A was up-regulated in different cancers. The aim of this work was to clarify the value of TIMM8A in the diagnosis, prognosis of Breast Cancer (BC), and its association with immune cells and immune detection points. Gene mutations.

Methods

The transcription and expression profile of TIMM8A between BC and normal tissues was downloaded from The Cancer Genome atlas (TCGA). The expression of TIMM8A protein was evaluated by human protein map. The correlation between TIMM8A and clinical features was analyzed using the R package to establish a ROC diagnostic curve. cBioPortal and MethSurv were used to identify gene alterations and DNA methylation and their effects on prognosis. The tumor immune estimation resource (TIMER) database and tumor immune system interaction database (TISIDB) database were used to determine the relationship between TIMM8A gene expression levels and immune infiltration. The CTD database was used to predict related drugs that inhibit TIMM8A, and the PubChem database was used to determine the molecular structure of potentially effective drug small molecules.

Results

The expression of TIMM8A in breast cancer tissues was significantly higher than that in normally adjacent tissues to cancer. ROC curve analysis showed that the AUC value of TIMM8A was 0.679. Kaplan-Meier method showed that patients with high TIMM8A had a lower prognosis (Overall Survival HR = 1.83 (1.31 − 2.54), P < 0.001) than patients with low TIMM8A expression of breast cancer (148.5 months vs. 115.4 months, P < 0.001). Methylation levels at seven CpG were associated with prognosis. Correlation analysis showed that TIMM8A expression was associated with tumor immune cell infiltration. There was a significant positive correlation of TIMM8A with PDL-1, and CTLA-4 in BC. In addition, CTD database analysis identified 15 small molecular drugs that target TIMM8A, such as Cyclosporine, Leflunomide, and Tretinoin, which might be effective therapies for targeted inhibition of TIMM8A.

Conclusion

In breast cancer, up-regulated TIMM 8A was significantly related to lower survival rate and higher immune invasiveness. Our research showed that TIMM 8A could be used as a biomarker for poor prognosis of breast cancer and a potential target of immunotherapy.

Long Non-coding RNA CCAT1 Sponges miR-454 to Promote Chemoresistance of Ovarian Cancer Cells to Cisplatin by Regulation of Surviving

Purpose

Colon cancer-associated transcript 1 (CCAT1) was identified as an oncogenic long non-coding RNA (lncRNA) in a variety of cancers. However, there was a lack of understanding of the mechanism by which CCAT1 conferred cisplatin (also known as DDP) resistance in ovarian cancer cells.

Materials and Methods

Cell viability of A2780, SKOV3, A2780/DDP, and SKOV3/DDP cells upon cisplatin treatment was monitored by MTT assay. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) detected the expression levels of CCAT1 and miR-454. The effect of sh-CCAT1 on cisplatin response was investigated in xenografts study. Bioinformatic analysis, luciferase reporter assay and qRT-PCR were conducted to validate the direct interaction among CCAT1, miR-454, and survivin. Apoptosis was determined by flow cytometry after dual staining of Annexin-V-FITC/propidium iodide, and the expression of apoptosis-related proteins Bcl-2, Bax and survivin were detected by qRT-PCR and Western blotting. Xenograft study was conducted to monitor in vivo tumor formation.

Results

CCAT1 was highly expressed in cisplatin-resistant ovarian cancer cell line A2780/DDP and SKOV3/DDP. Knockdown of CCAT1 restored sensitivity to cisplatin in vitro and in vivo. Our data revealed that silencing of CCAT1 promoted cisplatin-induced apoptosis via modulating the expression of pro- or anti-apoptotic proteins Bax, Bcl-2, and survivin. CCAT1 directly interacted with miR-454, and miR-454 overexpression potentiated cisplatin-induced apoptosis. Survivin was identified as a functional target of miR-454, restoration of survivin attenuated the effect of miR-454 on cisplatin response. In addition, miR-454 inhibitor or overexpression of survivin was found to abolish sh-CCAT1–induced apoptosis upon cisplatin treatment.

Conclusion

CCAT1/miR-454/survivin axis conferred cisplatin resistance in ovarian cancer cells.