ABSTRACT
Background: RNA modification is one of the epigenetic mechanisms that regulates post-transcriptional gene expression, and abnormal RNA modifications have been reported to play important roles in tumorigenesis. N7-methylguanosine (m7G) is an essential modification at the 5' cap of human mRNA. However, a systematic and pan-cancer analysis of the clinical relevance of m7G related regulatory genes is still lacking. Methods: We used univariate Cox model and Kaplan-Meier analysis to generate the forest plot of OS, PFI, DSS and identified the correlation between the altered expression of m7G regulators and patient survival in 33 cancer types from the TCGA and GTEx databases. Then, the "estimate" R-package, ssGSEA and CIBERSORT were used to depict the pan-cancer immune landscape. Through Spearman's correlation test, we analyzed the correlation between m7G regulators and the tumor microenvironment (TME), immune subtype, and drug sensitivity of the tumors, which was further validated in NSCLC. We also assessed the changes in the expression of m7G related regulatory genes in NSCLC with regards to the genetic and transcriptional aspects and evaluated the correlation of METTL1 and WDR4 expression with TMB, MSI and immunotherapy in pan-cancer. Results: High expression of most of the m7G regulators was significantly associated with worse prognosis. Correlation analyses revealed that the expression of majority of the m7G regulators was correlated with tumor immune infiltration and tumor stem cell scores. Drug sensitivity analysis showed that the expression of CYFP1,2 was closely related to drug sensitivity for various anticancer agents (p < 0.001). Analysis of the pan-cancer immune subtype revealed significant differences in the expression of m7G regulators between different immune subtypes (p < 0.001). Additionally, the types and proportions of mutations in METTL1 and WDR4 and their relevance to immunotherapy were further described. Conclusion: Our study is the first to evaluate the correlation between the altered expression of m7G regulators and patient survival, the degree of immune infiltration, TME and drug sensitivity in pan-cancer datasets.
ABSTRACT
Background: Imaging examinations following sublobar resection of lung cancer often find thickened neoplasms around the resection margin. Identifying whether the neoplasms are postoperative recurrence or margin granulomas is vitally important. However, the identification mainly depends on the empirical judgment of the imaging department or clinicians in each clinical center at present, and there are few relevant studies, so it is hard to formulate a relatively unified standard. Therefore, we collected data from patients with thickened neoplasms around the resection margin after sublobar resection and sought to discover how to differentiate granulomas from tumor recurrence. Methods: We examined the clinical records of 15 patients with neoplasms around the margins which identified as malignant in auxiliary examination reports, and received second surgery after first sublobar resection. We collected their postoperative pathology and auxiliary examination parameters. The univariate predictors helpful in distinguishing between recurrence and granuloma were analyzed as a diagnostic test. Results: Of the 15 patients with neoplasms around the resection margin, six were diagnosed with benign granulomas, and nine were diagnosed with primary lung cancer recurrence. The results revealed that age, gender, specific surgical method, maximum standardized fluorodeoxyglucose uptake value (SUVmax), and follow-up time were not significantly different, but there were significant differences in enhanced computed tomography (CT) values in several analyses, which calculated by the hospital imaging system. The maximum CT values of the tumor recurrence and granuloma were 104.9±8.051 and 130.3±7.017 (P=0.045), the minimum CT values (15.67±5.113 vs. -17.17±4.826, P=0.0007) and in the floating range CT values (148.00±5.471 vs. 88.11±7.671, P<0.0001), respectively. Conclusions: Differentiating between tumor recurrence and granulomas after sublobar resection remains difficult. However, examining the differences in enhanced CT allows the clinician to make an informed diagnosis that aids further investigation and treatment.
ABSTRACT
Perfluorooctane sulfonate (PFOS) is a persistent organic contaminant that may cause cardiotoxicity in animals and humans. However, little is known about the underlying mechanism by which it affects the organelle toxicity in cardiomyocytes during the cardiogenesis. Our previous proteomic study showed that differences of protein expression mainly existed in mitochondria of cardiomyocytes differentiated from embryonic stem (ES) cells after exposure to PFOS. Here, we focused on mitochondrial toxicity of PFOS in ES cell-derived cardiomyocytes. The cardiomyogenesis from ES cells in vitro was inhibited, and the expression of L-type Ca2+ channel (LTCC) was decreased to interrupt [Ca2+]c transient amplitude in cardiomyocytes after PFOS treatment. Transmission electron microscope revealed that swollen mitochondrion with vacuole in PFOS-treated cells. Meanwhile, mitochondrial transmembrane potential (ΔΨm) was declined and ATP production was lowered. These changes were related to the increased EGFR phosphorylation, activated Rictor signaling, then mediated HK2 binding to mitochondrial membrane. Furthermore, PFOS reduced the interaction of IP3R-Grp75-VDAC and accumulated intracellular fatty acids by activating Rictor, thereby attenuating PGC-1α and Mfn2 expressions, then destroying mitochondria-associated endoplasmic reticulum membrane (MAM), which resulted in the decrease of [Ca2+]mito transient amplitude triggered by ATP. In conclusion, mitochondrial structure damages and abnormal Ca2+ shuttle were the important aspects in PFOS-induced cardiomyocytes toxicity from ES cells by activating Rictor signaling pathway.
