circRNA18_46222157_46248185 inhibits melanogenesis by targeting miR-211/EP300 pathway in goat melanocytes.

Objective: This study investigated the effects of circRNA18_46222157_46248185 (named circRNA18) on goat melanogenesis, which differs significantly in goat skins isolated from white and brown coat-colored skins. Methods: Expression patterns of circRNA18 in goat skin and melanocytes were determined by qRT-PCR and In situ hybridization. The circRNA18 interference vector was designed and synthesized to transfect melanocytes and detect the effect of circRNA18 interference on melanin production. Bioinformatics software was used to predict the targeted adsorption miRNAs of circRNA18, verified by luciferase assay. miRNA expression vector was constructed and transfected into melanocytes to detect the effect of miRNA on melanin production, and the targeted regulatory genes were detected by luciferase assay. Target gene interference vector was constructed to detect the influence of target gene interference on melanin production. Results: qRT-PCR results unveiled distinct expression patterns of circRNA18 in diverse tissues of male and female goats, while in situ hybridization assays showed that circRNA18 is expressed in the cytoplasm of melanocytes. Functional analysis demonstrated that the downregulation of circRNA18 in melanocytes leads to a significant increase (P<0.01) in melanin production. Bioinformatics analysis identified a potential miR-211 binding site on circRNA18, and luciferase assay confirmed their interaction. Overexpression of miR-211 in melanocytes significantly augmented (P<0.01) melanin production. There were two potential miR-211 binding sites on adenoviral E1A-binding protein (EP300), and the overexpression of miR-211 in melanocytes significantly decreased (P<0.001) EP300 expression, with luciferase assay confirming their interaction. Downregulation of EP300 expression in melanocytes through siRNA-EP300 transfection results in a substantial increase (P<0.05) in melanin production. qRT-PCR results indicated that overexpression of mimics-circRNA18 in melanocytes markedly suppressed (P<0.0001) miR-211 expression, significantly elevated (P<0.01) EP300 expression, and significantly inhibited (P<0.001) melanin production. Conclusion: circRNA18_46222157_46248185 acted as a negative regulator of melanogenesis in goat melanocytes by targeting the miR-211/EP300 pathway, and guiding animal hair color breeding strategies.

Thioridazine reverses trastuzumab resistance in gastric cancer by inhibiting S-phase kinase associated protein 2-mediated aerobic glycolysis.

BACKGROUND: Trastuzumab constitutes the fundamental component of initial therapy for patients with advanced human epidermal growth factor receptor 2 (HER-2)-positive gastric cancer (GC). However, the efficacy of this treatment is hindered by substantial challenges associated with both primary and acquired drug resistance. While S-phase kinase associated protein 2 (Skp2) overexpression has been implicated in the malignant progression of GC, its role in regulating trastuzumab resistance in this context remains uncertain. Despite the numerous studies investigating Skp2 inhibitors among small molecule compounds and natural products, there has been a lack of successful commercialization of drugs specifically targeting Skp2. AIM: To discover a Skp2 blocker among currently available medications and develop a therapeutic strategy for HER2-positive GC patients who have experienced progression following trastuzumab-based treatment. METHODS: Skp2 exogenous overexpression plasmids and small interfering RNA vectors were utilized to investigate the correlation between Skp2 expression and trastuzumab resistance in GC cells. Q-PCR, western blot, and immunohistochemical analyses were conducted to evaluate the regulatory effect of thioridazine on Skp2 expression. A cell counting kit-8 assay, flow cytometry, a amplex red glucose/glucose oxidase assay kit, and a lactate assay kit were utilized to measure the proliferation, apoptosis, and glycolytic activity of GC cells in vitro. A xenograft model established with human GC in nude mice was used to assess thioridazine's effectiveness in vivo. RESULTS: The expression of Skp2 exhibited a negative correlation with the sensitivity of HER2-positive GC cells to trastuzumab. Thioridazine demonstrated the ability to directly bind to Skp2, resulting in a reduction in Skp2 expression at both the transcriptional and translational levels. Moreover, thioridazine effectively inhibited cell proliferation, exhibited antiapoptotic properties, and decreased the glucose uptake rate and lactate production by suppressing Skp2/protein kinase B/mammalian target of rapamycin/glucose transporter type 1 signaling pathways. The combination of thioridazine with either trastuzumab or lapatinib exhibited a more pronounced anticancer effect in vivo, surpassing the efficacy of either monotherapy. CONCLUSION: Thioridazine demonstrates promising outcomes in preclinical GC models and offers a novel therapeutic approach for addressing trastuzumab resistance, particularly when used in conjunction with lapatinib. This compound has potential benefits for patients with Skp2-proficient tumors.

Recent Development of Machine Learning Methods in Sumoylation Sites Prediction.

Sumoylation of proteins is an important reversible post-translational modification of proteins and mediates a variety of cellular processes. Sumo-modified proteins can change their subcellular localization, activity, and stability. In addition, it also plays an important role in various cellular processes such as transcriptional regulation and signal transduction. The abnormal sumoylation is involved in many diseases, including neurodegeneration and immune-related diseases, as well as the development of cancer. Therefore, identification of the sumoylation site (SUMO site) is fundamental to understanding their molecular mechanisms and regulatory roles. In contrast to labor-intensive and costly experimental approaches, computational prediction of sumoylation sites in silico has also attracted much attention for its accuracy, convenience, and speed. At present, many computational prediction models have been used to identify SUMO sites, but their contents have not been comprehensively summarized and reviewed. Therefore, the research progress of relevant models is summarized and discussed in this paper. We have briefly summarized the development of bioinformatics methods for sumoylation site prediction by mainly focusing on the benchmark dataset construction, feature extraction, machine learning method, published results, and online tools. We hope that this review will provide more help for wet-experimental scholars.

[Study of p16(INK4A) expression and DNA ploidy in HPV-negative cervical cancers and precursors].

OBJECTIVE: To investigate the clinicopathological significance of p16(INK4A) expression and DNA ploidy status in HPV-negative uterine cervical cancers and their precursors. METHODS: HPV-negative cervical lesions, including 20 cases of cervicitis, 20 cases of cervical intraepithelial neoplasm (CIN), 3 cases of cervical glandular intraepithelial neoplasm (CGIN), 38 cases of invasive squamous cell carcinoma (SCCs) and 15 cases of invasive adenocarcinoma were selected and subject to screening for HPV infection by PCR method. The p16(INK4A) protein expression and DNA ploidy status were studied by immunohistochemistry and flow cytometry respectively. RESULTS: Specific expression of p16(INK4A) was seen in both the nucleus and cytoplasm of the dysplastic and malignant cells of CIN, CGIN, cervical SCC and adenocarcinoma. In contrast, no expression was present in normal and inflammatory squamous or glandular epithelium. DNA aneuploidy was significantly more frequent in invasive SCCs and adenocarcinomas than in CIN (P < 0.01). Aneuploid was also more frequent in the lymph node positive group than lymph node negative group, although no statistic significance was found. Among the 8 cases of p16(INK4A) negative SCCs, two showed DNA aneuploidy. CONCLUSIONS: Immunohistochemical detection for p16(INK4A) can be an early diagnostic marker for HPV-negative cervical SCC and adenocarcinoma. DNA ploidy analysis may further assist the diagnosis of cervical malignancies.