Mingyang Li

LSD1 Demethylates and Destabilizes Autophagy Protein LC3B in Ovarian Cancer

Autophagy is a complex cellular process that can either promote or inhibit cancer progression and development, depending on the context and molecular regulation involved. This study investigates how LSD1 regulates autophagy in ovarian cancer by interacting with the autophagy protein LC3B. Utilizing the bioinformatic analysis of TCGA, CPTAC, and GEO datasets, as well as immunohistochemistry in ovarian cancer patients, we explored the expression association between LSD1 and LC3B. Molecular mechanisms were further analyzed using Western blotting, immunoprecipitation, and GST pull-down assays. Our findings reveal that LSD1 binds to LC3B via its SWIRM domain, and high levels of LSD1 are closely associated with aggressive ovarian cancer and poor patient outcomes. Mechanistically, LSD1 demethylates LC3B, leading to decreased LC3B stability. The observed inverse correlation between LSD1 expression and LC3B protein levels in clinical samples underscores the need for further investigation to elucidate how reduced LC3B protein levels induced by LSD1 demethylation may contribute to ovarian cancer.

SETD7 promotes LC3B methylation and degradation in ovarian cancer

Microtubule-associated protein 1 light chain 3 (LC3) is a key autophagy-related protein involved in regulating autophagosome formation and autophagy activity. Post-translational modifications of LC3 are necessary to modulate its function. However, LC3 protein methylation and its physiological significance have not yet been elucidated. Here, we show that SET domain containing lysine methyltransferase 7 (SETD7) interacts with LC3B, a common isoform of LC3, and methylates LC3B at lysine 51 (K51). SETD7-mediated methylation of LC3B promotes ubiquitination and degradation of LC3B, resulting in reduced autophagosome formation. Furthermore, SETD7 exerts a tumor-promotive function in ovarian cancer (OC) cells in a K51 methylation-dependent manner. Collectively, our data define a novel modification of LC3B and highlight the oncogenic effect of SETD7 via mediating LC3B methylation and degradation.

ZIC5 promotes aggressiveness and cancer stemness in cervical squamous cell carcinoma

Cervical cancer is one of the major malignancies causing morbidity and mortality in women in developing countries. ZIC5 has been found to be associated with a variety of cancers, yet the expression and molecular function of ZIC5 in cervical squamous cell carcinoma (CESC) is unknown. We examined the expression of ZIC5 in tumors and normal tissues of CESC patients using immunohistochemistry, immunoblotting and fluorescent quantitative PCR, and used statistical methods to explore its relationship with clinical manifestations. Next, we constructed ZIC5 knockdown and overexpression CESC cell lines to observe the effect of ZIC5 on the proliferation and metastasis of CESC cells. Finally, we applied a nude mouse xenograft tumor model to observe the effect of ZIC5 on tumorigenesis in vivo. Our results showed that the expression of ZIC5 was higher in cancer tissues than in normal tissues. Prognostic analysis showed that ZIC5 expression level was an independent prognostic factor in CESC patients, and the results of Transwell, CCK-8 and wound healing assays confirmed that overexpression of ZIC5 could promote the proliferation and migration of CESC cells. A nude mouse xenograft tumor model showed that knockdown of ZIC5 inhibited tumor growth in vivo. Database, immunoblotting assay and in vitro sphere-forming assay confirmed that ZIC5 could promote the stemness of CESC cells. ZIC5 is a factor that indicates a poor prognosis of CESC patients and promotes stemness in CESC cells. ZIC5 may be a potential biomarker and therapeutic target for CESC patients.

TRIM21 promotes tumor progression and cancer stemness in cervical squamous cell carcinoma

The ubiquitin ligase family member triplex motif protein 21 (TRIM21), which is involved in the proliferation, metastasis, and selective death of tumor cells, is crucial in the ubiquitination of a number of tumor marker proteins. As research progresses, more studies demonstrate that TRIM21 expression levels can be used to predict cancer prognosis. However, it is unclear how exactly TRIM21 contributes to cervical squamous carcinoma. Immunohistochemistry, Western Blot, and q-PCR were utilized to determine the expression level of TRIM21 in 113 patients with CESC removed by stage I surgery at Xijing Hospital from 2018 to 2023 using paraffin-embedded tumor tissues and 12 pairs of fresh tumor tissues and their paracancerous tissues. Log-rank analysis using SPSS 23.0 was performed for prognosis and survival analysis using univariate/multifactorial analysis. CCK-8, wound-healing and Scratch assay verified that TRIM21 promoted cell proliferation, migration and invasion. The effect of overexpression and knockdown of TRIM21 on tumor stemness was examined using sphere-forming assay and Western Blot. Finally, we constructed a xenograft model to observe the effect of TRIM21 on tumorigenesis in Si Ha cell lines in vivo. TRIM21 expression is greater in CESC tissues than in paracancerous tissues, according to immunohistochemical data. Similarly, at the protein and mRNA levels, we verified this conclusion using Western-Blotting and q-PCR. Prognostic and OS analysis showed that TRIM21 expression levels are associated with individual prognostic factors. CCK-8, Wound healing, Transwell, and Sphere-forming tests all demonstrated that TRIM21 overexpression enhances Ca Ski cell proliferation, migration, invasion, and stemness. TRIM21 knockdown in Si Ha inhibited tumor cell proliferation, migration, invasion, and stemness. The experimental results of xenograft models demonstrated that TRIM21 knockdown in Si Ha cells inhibited tumor development. TRIM21 is a poor predictor of prognosis for cervical squamous cell carcinoma and might open up new avenues for investigation into therapeutic targets.

UCHL1 acts as a prognostic factor and promotes cancer stemness in cervical squamous cell carcinoma

The incidence and death rate of cervical cancer rank fourth among female malignant tumors worldwide. A growing number of researches are devoted to exploring more effective treatment methods and cancer stem cells (CSCs) are thought to be a potential therapeutic target in cervical cancer. In our study, we focused on the expression and function of UCHL1 in cervical squamous cell carcinoma (CESC). We detected and the expression of UCHL1 in 134 CESC patients through immunohistochemistry and further confirm UCHL1 was a prognostic factor by univariate and multivariate analysis. Then, according to TCGA database for CESC, we found that UCHL1 expression correlated with the markers associated with CSCs (CD133, ABCG2 and SOX2). Therefore, we used western blot and spheroid formation assays to future evaluate the function of UCHL1 on cancer stemness in C-33A and SiHa cell lines. At the same time, we detected the cell proliferation, migration and invasion change by CCK-8 assay, scratch assay and transwell assay, when UCHL1 was knockdown or overexpressed. Finally, xenograft models were used to examine the effect of UCHL1 in vivo. We found the expression of UCHL1 in mRNA and protein was higher in tumor than in paired normal tissue and was a prognostic factor in CESC. The UCHL1 high expression group showed a shorter survival in the overall survival. According to TCGA database, the expression of UCHL1 was correlated with CD133, ABCG2 and SOX2. The results of sphere-forming ability and CSCs related markers expression were showed UCHL1 promoted cancer stemness in CESC. Similarly, CCK-8 assay, scratch assay and transwell assay were applied to demonstrate that overexpression of UCHL1 promoted the proliferation, migration and invasion in SiHa, but when UCHL1 was knockdown in C-33A, the function of UCHL1 displayed the opposite result. Finally, knockdown UCHL1 inhibited CESC tumor propagation in xenograft models. Our results suggest that UCHL1 is a prognostic factor and correlated with cancer stemness, proliferation, migration and invasion of CESC, which may provide a novel therapeutic strategy for CESC treatment.