Effect of benzo[a]pyrene on proliferation and metastasis of oral squamous cell carcinoma cells: A transcriptome analysis based on RNA-seq

Evaluation of CYP1B1, oxidative stress and phase II detoxification enzyme status in oral cancer progression model

Background

Tobacco is one of the main etiological factors for oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD). CYP1B1 is an enzyme which plays a major role in the phase I detoxification of tobacco, the byproducts of which are subsequently detoxified by phase II enzymes Glutathione S Transferase (GST). We attempted to evaluate the L432V polymorphism and tissue expression of CYP1B1, along with the oxidant-antioxidant status in OSCC progression model.

Method

ology: Tissue biopsies and blood samples were collected from the subjects; L432V polymorphism was evaluated by TaqMan RT-PCR, immunohistochemistry was performed on the tissue sample using CYP1B1 polyclonal primary antibody and Allred quick scoring system was used to evaluate the stained slides. Malonaldehyde (MDA) and GST activity were measured spectrophotometrically to assess oxidative-antioxidative status.

Results

When the L432V polymorphism was analyzed, it was observed that in oral epithelial dysplasia (OED) and OSCC, CG was more common than GG genotype. Highest mean Allred score was observed in tobacco users (6.27), highest GST activity was seen in oral epithelial dysplasia (5.006 U/ml) and highest MDA activity was observed in OSCC (1553.94 nm/ml).

Conclusion

Tobacco users with CG and GG genotypes are at equal risk of developing oral epithelial dysplasia or OSCC and L432V polymorphism does not appear to increase the risk of malignant transformation in oral epithelial dysplasia. Moreover, tobacco users with GG genotype and tissue expression of CYP1B1 may be at a greater risk of oxidative damage.

Genetic variants of antioxidant and xenobiotic metabolizing enzymes and their association with prostate cancer: A meta-analysis and functional in silico analysis

The development and progression of prostate cancer (PCa) depends on complex interactions between genetic, environmental and dietary factors that modulate the carcinogenesis process. Interactions between chemical exposures and genetic polymorphisms in genes encoding xenobiotic metabolizing enzymes (XME), antioxidant enzymes and DNA repair enzymes have been reported as the main drivers of cancer. Thus, a better understanding of the causal risk factors for PCa will provide avenues to identify men at increased risk and will contribute to develop effective detection and prevention methods. We performed a meta-analysis on 17,518 cases and 42,507 controls obtained from 42 studies to determine whether seven SNPs and one CNV pertaining to oxidative stress, xenobiotic detoxification and DNA repair enzymes are associated with the risk of PCa (GPX1 (rs1050450), XRCC1 (rs25487), PON1 (rs662), SOD2 (rs4880), CAT (rs1001179), GSTP1 (rs1695) and CNV GSTM1). A significant increased risk of PCa was found for SOD2 (rs4880) ORGG+GA vs. AA 1.08; 95%CI 1.01-1.15, CAT (rs1001179) ORTT vs. TC+CC 1.39; 95%CI 1.17-1.66, PON1 (rs662) ORCT vs. CC+TT 1.17; 95%CI 1.01-1.35, GSTP1 (rs1695) ORGG vs. GA+AA 1.20; 95%CI 1.05-1.38 and GSTM1 (dual null vs. functional genotype) ORN vs. NN1+NN2 1.34; 95%CI 1.10-1.64. The meta-analysis showed that the CNV GSTM1, and the SNPs GSTP1 (rs1695) and CAT (rs1001179) are strongly associated with a greater risk of PCa and, to a lesser extent, the genetic variants SOD2 (rs4880) and PON1 (rs662). Although several antioxidant enzymes and XME play an important role in the PCa development, other risk factors such as chemical exposures should also be considered to gain insight on PCa risk. The functional in silico analysis showed that the genetic variants studied had no clinical implication regarding malignancy, except for GPX1 (rs1050450) SNP.

Tumor-associated macrophages-derived exo-let-7a promotes osteosarcoma metastasis via targeting C15orf41 in osteosarcoma

BACKGROUND

Osteosarcoma (OS) immune environment is complexed and the immune factors-related to OS progression need to be explored. Tumor-associated macrophages (TAMs) are regarded as immune suppressive and tumor-promoting cells. However, the underlying mechanisms through which TAMs function are still fragmentary. Here, we aim to explore the underlying mechanisms by which TAMs regulate OS progression.

METHODS

TAMs from OS tissues were isolated by flow cytometry. Exosomes derived from TAMs were separated using ultracentrifugation and western blotting. Transmission electron microscopy (TEM), and flow cytometry were constructed to characterize TAMs-derived exosomes. Additionally, the differential MicroRNAs (miRNAs) and genes were detected through RNA sequencing, and further validated using real-time PCR (RT-PCR). OS cell metastasis ability was assessed using transwell invasion and scratch wound healing assays. MiRNAs mimic and lentiviral vectors were utilized to explore the effects on OS progression.

RESULTS

Exosome secreted by TAMs accelerated the OS metastasis. Let-7a level was upregulated in TAMs derived exosomes, which downregulated C15orf41 by targeting 3'-untranslated region (UTR). Furthermore, overexpressing let-7a enhanced invasion and migration by blocking the transcription of C15orf41. In consistent, up-regulating let-7a promoted OS progression and made the prognosis to be worse, which can be reversed by C15orf41 overexpression.

CONCLUSION

This study highlighted the critical role of TAMs-derived exosomes in OS progression and explored the potential value of the let-7a/C15orf41 axis as an indicator or target for OS.

Clusterin and Its Isoforms in Oral Squamous Cell Carcinoma and Their Potential as Biomarkers: A Comprehensive Review

Oral squamous cell carcinoma (OSCC) is a prevalent type of head and neck cancer, ranked as the sixth most common cancer worldwide, accounting for approximately 300,000 new cases and 145,000 deaths annually. Early detection using biomarkers significantly increases the 5-year survival rate of OSCC by up to 80-90%. Clusterin (CLU), also known as apolipoprotein J, is a sulfated chaperonic glycoprotein expressed in all tissues and human fluids and has been reported to be a potential biomarker of OSCC. CLU has been implicated as playing a vital role in many biological processes such as apoptosis, cell cycle, etc. Abnormal CLU expression has been linked with the development and progression of cancers. Despite the fact that there are many studies that have reported the involvement of CLU and its isoforms in OSCC, the exact roles of CLU and its isoforms in OSCC carcinogenesis have not been fully explored. This article aims to provide a comprehensive review of the current understanding of CLU structure and genetics and its correlation with OSCC tumorigenesis to better understand potential diagnostic and prognostic biomarker development. The relationship between CLU and chemotherapy resistance in cancer will also be discussed to explore the therapeutic application of CLU and its isoforms in OSCC.