Breast cancer is the most common type of carcinoma in women worldwide, but the mechanisms underlying tumour development and progression remain unclear. Sphingomyelin synthase 2 (SGMS2) is a crucial regulator involved in ceramide (Cer) and sphingomyelin (SM) homoeostasis that is mostly studied for its role in lipid metabolism. Our primary study indicated that high SGMS2 expression is associated with breast cancer metastasis. Gain- and loss-of-function assays in vitro and in vivo revealed that SGMS2 promotes cancer cell proliferation by suppressing apoptosis through a Cer-associated pathway and promotes cancer cell invasiveness by enhancing epithelial-to-mesenchymal transition (EMT) initiation through the TGF-β/Smad signalling pathway. Further study determined that SGMS2 activated the TGF-β/Smad signalling pathway primarily by increasing TGF-β1 secretion, which was likely associated with aberrant expression of SM. Thus, our findings indicate that SGMS2-mediated activation of the TGF-β/Smad signalling pathway is important in breast cancer progression, which provides new insight into the mechanisms underlying breast cancer metastasis and suggests a possible anticancer therapy for breast cancer.
Glioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.
Alcohol intake is a well-known lifestyle risk factor for CRC, and an increasing number of studies have revealed that alcohol intake is also tightly associated with CRC metastasis. However, the effect of alcohol on CRC metastasis and its underlying mechanism remain unclear. A retrospective cohort study was performed to investigate the characteristics of patients with alcohol-related CRC. The effects of ethanol on the biological behaviours of CRC cells were assessed through in vivo and in vitro assays using the Lieber-DeCarli ethanol liquid diet and ethanol, respectively. The ethanol-mediated signalling pathway and downstream factors were screened through ELISA, western blot, immunofluorescence and co-immunoprecipitation. Most patients with alcohol-related CRC, particularly those with tumour metastasis, were characterized by a notably higher circulating ethanol level and a lower systemic acetaldehyde level. Moreover, CRC cells accumulated in ethanol, but not acetaldehyde, to notably higher levels compared with adjacent normal cells. Alcohol intake significantly promoted CRC metastasis via the ethanol-mediated TGF-β/Smad/Snail axis, and ethanol induced the cytoplasmic mislocalization of RUNX3 and further promoted the aggressiveness of CRC by targeting Snail. Pirfenidone (PFD) significantly eliminated the effects of ethanol on CRC metastasis by specifically blocking TGF-β signalling. Alcohol intake plays a vital role in CRC metastasis via the ethanol-mediated TGF-β/RUNX3/Snail axis, and PFD might be a novel therapeutic management strategy for CRC.
1 December 2022 in Journal of Gastrointestinal Oncology
The boundary knot method (BKM) is a boundary-type meshfree method. Only non-singular general solutions are used during the whole solution procedures. The effective condition number (ECN), which depends on the right-hand side vector of a linear system, is considered as an alternative criterion to the traditional condition number. In this paper, the effective condition number is used to help determine the position and distribution of the collocation points as well as the quasi-optimal collocation point numbers. During the solution process, we propose an NMN-search algorithm. Numerical examples show that the ECN is reliable to measure the feasibility of the BKM.