A comprehensive bioinformatics analysis to identify a candidate prognostic biomarker for ovarian cancer

FoxO1 promotes ovarian cancer by increasing transcription and METTL14-mediated m6A modification of SMC4

The transcription factor forkhead box protein O1 (FoxO1) is closely related to the occurrence and development of ovarian cancer (OC), however its role and molecular mechanisms remain unclear. Herein, we found that FoxO1 was highly expressed in clinical samples of OC patients and was significantly correlated with poor prognosis. FoxO1 knockdown inhibited the proliferation of OC cells in vitro and in vivo. ChIP-seq combined with GEPIA2 and Kaplan-Meier database analysis showed that structural maintenance of chromosome 4 (SMC4) is a downstream target of FoxO1, and FoxO1 promotes SMC4 transcription by binding to its -1400/-1390 bp promoter. The high expression of SMC4 significantly blocked the tumor inhibition effect of FoxO1 knockdown. Furtherly, FoxO1 increased SMC4 mRNA abundance by transcriptionally activating methyltransferase-like 14 (METTL14) and increasing SMC4 m6A methylation on its coding sequence region. The Cancer Genome Atlas dataset analysis confirmed a significant positive correlation between FoxO1, SMC4, and METTL14 expression in OC. In summary, this study revealed the molecular mechanisms of FoxO1 regulating SMC4 and established a clinical link between the expression of FoxO1/METTL14/SMC4 in the occurrence of OC, thus providing a potential diagnostic target and therapeutic strategy.

SMC4 serves as a potential marker for the diagnosis and prognosis of colon adenocarcinoma

OBJECTIVE

We aimed to explore the role of structural maintenance of chromosomes 4 (SMC4) in malignant progression and immunology of colon adenocarcinoma (COAD).

METHODS

The expression, genetic and protein features, and immune cell infiltration of SMC4 in pan-cancer were provided by public databases and websites. The protein expression of SMC4 in COAD tissues was screened by immunohistochemical assay. Si-RNA-mediated transfection was performed in COAD cells and the proliferation viability was measured using MTT, colony formation and EdU assays. Cell autophagy was detected by AO staining, western blots, and immunofluorescence staining. The migratory ability was determined using scratch and transwell assays. The expression of epithelial-to-mesenchymal transition (EMT) markers and transcriptional factors were detected using western blots.

RESULTS

The expression of SMC4 was upregulated in pan-cancer and had relationships with prognosis, TMB, and MSI of cancer patients. Particularly, SMC4 protein was highly expressed in COAD tissues and correlated with poor prognosis of patients. Depletion of SMC4 inhibited cell proliferation, induced autophagy, and decreased migration through EMT progression in COAD cells. In addition, SMC4 was associated with infiltration of neutrophils, M2 macrophages, and CD4 + T cells in COAD, and had positive association with M2 macrophage markers and immune checkpoints.

CONCLUSION

SMC4 was correlated with patients' poor prognosis, proliferation, metastasis, and immune cell infiltrates, and might function as a potential diagnosis and prognostic biomarker in COAD.

Association of SMC4 with prognosis and immune infiltration of sarcoma

OBJECTIVE

This study was performed to explore the prognostic relevance of structural maintenance of chromosomes 4 (SMC4) in pan-cancer and explore the association between SMC4 and immune infiltration of sarcoma.

RESULTS

Elevated expression of SMC4 was detected in cancer tissues compared to normal tissue, which was confirmed in synovial sarcoma tissues with immunohistochemistry (IHC). Additionally, higher expression of SMC4 was connected to worse outcomes of sarcoma, gastric cancer, breast cancer, liver cancer or ovarian cancer. Moreover, SMC4 was positively connected to immune cell infiltrates in sarcoma. In addition, infiltrating immune cell markers including monocyte, TAM, M1 and M2 presented different SMC4-associated immune infiltration patterns.

CONCLUSION

The results from our study showed that SMC4 was positively related to the prognosis and immunological status of sarcoma. SMC4 could be a potential biomarker for prognosis and immune cell infiltrates in sarcoma.

METHODS

Several databases including ONCOMINE, GEPIA, and Kaplan-Meier Plotter were adopted to explore the expression pattern of SMC4 in sarcoma, which was confirmed by IHC. The GEPIA and TIMER datasets were adopted to investigate the associations between SMC4 and prognosis in various cancers, especially in sarcoma.

Elevated BTG2 improves the radiosensitivity of non-small cell lung cancer (NSCLC) through apoptosis

BACKGROUND

To identify radio-responsive genes and explore the biological function of encoded proteins in non-small cell lung cancer (NSCLC).

METHODS

Radio-responsive genes in irradiated H460 cells were screened from microarray data deposited in the Gene Expression Omnibus (GEO) database. A quantitative real time polymerase chain reaction assay was used to detect the expression of candidate radio-responsive genes in irradiated cells. CCK-8 assay, EDU assay, clone formation assay, immunofluorescence and flow cytometry were conducted to evaluate the biological function of B cell translocation gene 2 (BTG2) in NSCLC.

RESULTS

Bioinformatic analysis using GES20549 showed that BTG2 was a radio-responsive gene in irradiated H460 cells. The mRNA expression level of BTG2 was lower in H460 cells compared with that in BEAS-2B normal lung epithelial cells. BTG2 expression was elevated upon IR exposure, in a dose-dependent but not a time-dependent manner. CCK-8 and EDU assays revealed that BTG2 overexpression inhibited the growth rate of irradiated cells. Clone formation showed that elevated BTG2 promoted DNA damage of irradiated H460 cells. The number of γ-H2AX foci induced by DNA damage was also markedly increased upon BTG2 overexpression. Flow cytometry showed that BTG2 increased IR-induced cell apoptosis.

CONCLUSIONS

BTG2 may be a novel radio-responsive factor and a promising therapeutic target for radiotherapy of NSCLC.