Clinical comments on prognostic and clinicopathological significance of PD-L1 overexpression in oral squamous cell carcinoma (OSCC)

Clinical Investigation of Chemotherapeutic Resistance and miRNA Expressions in Head and Neck Cancers: A Thorough PRISMA Compliant Systematic Review and Comprehensive Meta-Analysis

Background: Chemoresistance is a significant barrier to combating head and neck cancer, and decoding this resistance can widen the therapeutic application of such chemotherapeutic drugs. This systematic review and meta-analysis explores the influence of microRNA (miRNA) expressions on chemoresistance in head and neck cancers (HNC). The objective is to evaluate the theragnostic effects of microRNA expressions on chemoresistance in HNC patients and investigate the utility of miRNAs as biomarkers and avenues for new therapeutic targets. Methods: We performed a comprehensive bibliographic search that included the SCOPUS, PubMed, and Science Direct bibliographic databases. These searches conformed to a predefined set of search strategies. Following the PRISMA guidelines, inclusion and exclusion criteria were framed upon completing the literature search. The data items extracted were tabulated and collated in MS Excel. This spreadsheet was used to determine the effect size estimation for the theragnostic effects of miRNA expressions on chemoresistance in HNC, the hazard ratio (HR), and 95% confidence intervals (95% CI). The comprehensive meta-analysis was performed using the random effects model. Heterogeneity among the data collected was assessed using the Q test, Tau², I², and Z measures. Publication bias of the included studies was checked using the Egger's bias indicator test, Orwin and classic fail-safe N test, Begg and Mazumdar rank collection test, and Duval and Tweedie's trim and fill methods. Results: After collating the data from 23 studies, dysregulation of 34 miRNAs was observed in 2189 people. These data were gathered from 23 studies. Out of the 34 miRNAs considered, 22 were up-regulated, while 12 were down-regulated. The TaqMan transcription kits were the most used miRNA profiling platform, and miR-200c was seen to have a mixed dysregulation. We measured the overall pooled effect estimate of HR to be 1.516 for the various analyzed miRNA at a 95% confidence interval of 1.303-1.765, with a significant p-value. The null hypothesis test's Z value was 5.377, and the p-value was correspondingly noted to be less than 0.0001. This outcome indicates that the risk of death is determined to be higher in up-regulated groups than in down-regulated groups. Among the 34 miRNAs that were investigated, seven miRNAs were associated with an improved prognosis, especially with the overexpression of these seven miRNAs (miR15b-5p, miR-548b, miR-519d, miR-1278, miR-145, miR-200c, Hsa- miR139-3p). Discussion: The findings reveal that intricate relationships between miRNAs' expression and chemotherapeutic resistance in HNC are more likely to exist and can be potential therapeutic targets. This review suggests the involvement of specific miRNAs as predictors of chemoresistance and sensitivity in HNC. The examination of the current study results illustrates the significance of miRNA expression as a theragnostic biomarker in medical oncology.

Silencing of SETD6 inhibits the tumorigenesis of oral squamous cell carcinoma by inhibiting methylation of PAK4 and RelA

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most comment types of oral malignancies. SET-domain-containing protein 6 (SETD6) was recently identified as an important regulator of multiple signaling pathways through methylating protein substrates. Meanwhile, SETD6 is known to participate in multiple cancers. However, the role of SETD6 in OSCC remains unclear.

METHODS

Gene and protein expressions in OSCC cells or tissues were detected by RT-qPCR and western blot, respectively. In addition, CCK-8 assay was used to test the cell viability. A transwell assay was performed to measure cell migration and invasion. Flow cytometry was used to test cell apoptosis and cycle. Meanwhile, methylation-specific PCR (MSP) was used to detect the status of promoter methylation.

RESULTS

SETD6 was significantly upregulated in OSCC tissues. In addition, knockdown of SETD6 notably inhibited the proliferation and induced the apoptosis of OSCC cells. Furthermore, silencing of SETD6 notably suppressed the migration and invasion of OSCC cells. Meanwhile, SETD6 siRNA significantly inhibited the promoter methylation of RelA (NF-κB p65) and PAK4. Furthermore, SETD6 siRNA induced G1 arrest in OSCC cells.

CONCLUSION

Knockdown of SETD6 inhibits the tumorigenesis of OSCC by suppressing promoter methylation of PAK4 and RelA. Therefore, our study might shed new light on exploring strategies for the treatment of OSCC.