PurposeBasal layer type squamous cell carcinoma (BLSCC) is a unique type of squamous cell carcinoma (SCC), characterized by high-grade dysplastic cells occupying the lower half of the epithelium. So far, such special lesions do not seem to attract much attention. The aim of this study was to investigate the clinicopathological features and prognosis of esophageal squamous carcinoma lesions with a BLSCC component.Materials and methodsBetween January 2011 and January 2018, 96 patients with esophageal squamous cell carcinoma underwent endoscopic submucosal resection in our hospital were retrospectively analyzed. Patients were divided into BLSCC or typical SCC groups according to the presence or absence of a BLSCC component. The endoscopic findings were compared between the two groups. Furthermore, patients were followed up until October 2018 to compare recurrence rates.ResultsBLSCC components were detected in 32 (33.3%, 32/96) lesions. Among them, 13 (40.62%, 13/32) were BLSCC predominant. The intraepithelial papillary capillary loops of 7 pure BLSCC showed type B1 under narrow-band imaging. Single-factor and multivariate analyses indicated that five or more independently scattered, deep-stained spots in iodine-unstained areas were significantly predictive of the presence of BLSCC components (OR=4.837, P=0.015). All patients of typical SCC group survived, but one of BLSCC group died for distant metastases during the follow-up period. The 1-year cumulative recurrence rate (CRR) of BLSCC group were 3.4%, lower than that of typical SCC group (7.1%). Although no significant difference of CRR was seen between the two groups (P>0.05), the 2-year CRR of BLSCC group increased to 11.9%, being higher than that of typical SCC group (7.1%).ConclusionThe presence of multiple, scattered stained spots in iodine-unstained areas was predictive of BLSCC components. Such lesion should be treated actively and subject to a more rigorous follow-up protocol due to a higher likelihood of late recurrence.

No abstract

Angiogenesis is hijacked by cancer to support tumor growth. RNA modifications such as N6-methyladenosine (m6A) can regulate several aspects of cancer, including angiogenesis. Here, we find that m6A triggers angiogenesis in lung cancer by upregulating vascular endothelial growth factor-A (VEGFA), a central regulator of neovasculature and blood vessel growth. m6A-sequencing and functional studies confirmed that m6A modification of the 5’UTR of VEGFA positively regulates its translation. Specifically, methylation of a 5’UTR internal ribosome entry site (IRES) recruited the YTHDC2/eIF4GI complex to trigger cap-independent translation initiation. Intriguingly, the m6A methylation site A856 of the 5’UTR was located within the conserved upstream open reading frame (uORF) of VEGFA IRES-A, which overcomes uORF-mediated translation suppression while facilitating G-quadruplex-induced translation of VEGFA. Targeted specific demethylation of VEGFA m6A significantly decreased expression of VEGFA and reduced lung cancer cell-driven angiogenesis. In vivo and clinical data confirmed the positive effects of m6A modification of VEGFA on angiogenesis and tumor growth of lung cancer. This study not only reveals that the m6A/VEGFA axis is a potential target for lung cancer therapy but also expands our understanding of the impact of m6A modification of IRES in the 5’UTR of mRNA on translation regulation.

Long non-coding RNA (lncRNA) prostate cancer-associated transcript 18 (PCAT18) is a potential diagnostic target for adenocarcinoma. However, its role in triple-negative breast cancer (TNBC) remains largely unknown. Based on data from an online database, a significant decline in lncRNA PCAT18 was observed in patients with TNBC subtype compared to a population with normal breast tissue. Patients with TNBC with high PCAT18 levels presented good outcomes. Patients with TNBC with high PCAT18 had a lower rate of lymph node-positive metastasis than those with low PCAT18. PCAT18-upregulation inhibited, while PCAT18-downregulation promoted, migration and expression of matrix metalloproteinases 9/2 (MMP9/MMP2) and uridylyl phosphate adenosine (uPA) in TNBC cells. Activating transcription factor 7 (ATF7) was positively associated with PCAT18, and ATF7-inhibition abrogated the anti-migration effects of PCAT18 on TNBC cells. Mechanistically, miR-103a-3p directly targeted and inhibited ATF7 expression. PCAT18 competitively sponges miR-103a-3p, promoting the expression of ATF7. Exogenous PCAT18 was associated with lower incidence of lung metastasis followed by the upregulation of ATF7, which was prevented by the treatment of miR-103a-3p mimics. Collectively, PCAT18 was expressed at low levels in TNBC, and PCAT18 could sponge miR-103a-3p and promote ATF7 expression, resulting in prevention of TNBC metastasis. Thus, PCAT18 can serve as a predictive factor for patients with metastatic TNBC.