pitstop-2 and Liver-Neoplasms

Endocytosis is a fundamental process for internalizing small extracellular vesicles (sEVs). The present study aimed to elucidate the role of clathrin light chain A (CLTA) in sEV uptake in hepatocellular carcinoma (HCC).. CLTA expression was analyzed by bioinformatics, quantitative PCR and immunohistochemistry. The clinical relevance of CLTA was analyzed by Fisher's exact test, Kaplan-Meier analysis, and multivariate cox regression model. The functions of CLTA in sEV uptake and cancerous properties were examined by PKH67-sEV uptake, MTT, colony formation, and transwell assays. Mass spectrometry was used to identify the downstream effectors of CLTA. CLTA inhibitor, Pitstop 2, was tested in a mouse model of patient-derived xenografts (PDXs).. CLTA expression was higher in tumor tissues than in non-tumorous liver tissues and progressively increased from the early to late tumor stage. CLTA overexpression was associated with larger tumor size and poor prognosis in HCC. Cellular CLTA contributed to the sEV uptake, resulting in enhanced cancerous properties. Mechanistically, CLTA increases capping actin protein gelsolin-like (CAPG) expression to facilitate sEV uptake, thereby promoting the proliferation, motility, and invasiveness of HCC cells. What's more, the CLTA inhibitor Pitstop 2 alone or in combination with sorafenib attenuated tumor growth in mice implanted with PDXs.. The study reveals the role of CLTA in sEV uptake to promote HCC progression. Inhibition of CLTA and its mediated pathway illuminate a new therapeutic strategy for HCC patients.

Topics: Animals; Carcinoma, Hepatocellular; Cell Line, Tumor; Clathrin Light Chains; Extracellular Vesicles; Humans; Liver Neoplasms; Mice

Liver cancer is the fifth most frequently diagnosed type of cancer in men worldwide. Recombinant human programmed cell death 5 (rhPDCD5) has been shown to enter a variety of cells by clathrin-independent endocytosis. Tissue specimens from 32 hepatocellular carcinoma (HCC) patients were collected for analysis of PDCD5 expression using ELISA. It was confirmed that the pre‑operative serum levels of PDCD5 protein in patients with HCC were significantly lower than the post‑operative serum levels. Moreover, the serum PDCD5 levels were significantly correlated with portal invasion and lymph node metastasis. rhPDCD5 inhibited cell proliferation as indicated by an MTT assay, and induced apoptosis and S-phase arrest in HCC cells as demonstrated by flow cytometric analysis. Furthermore, rhPDCD5 suppressed tumor growth in established xenograft tumor models. In addition, Pitstop2 was used to block clathrin-dependent endocytosis (CDE), which confirmed that the anti‑tumor effect of rhPDCD5 in HCC cells is mediated via CDE.

Topics: Animals; Antineoplastic Agents; Apoptosis Regulatory Proteins; Carcinoma, Hepatocellular; Endocytosis; Female; Genetic Engineering; Humans; Liver Neoplasms; Male; Mice, Inbred NOD; Mice, SCID; Middle Aged; Neoplasm Proteins; Recombinant Fusion Proteins; Sulfonamides; Thiazolidines; Tumor Cells, Cultured; Xenograft Model Antitumor Assays