Targeting PUF60 prevents tumor progression by retarding mRNA decay of oxidative phosphorylation in ovarian cancer.

PURPOSE: Ovarian cancer (OC) is the leading cause of death from gynecological malignancies, and its etiology and pathogenesis are currently unclear. Recent studies have found that PUF60 overexpressed in various cancers. However, the exact function of PUF60 in global RNA processing and its role in OC has been unclear. METHODS: The expression of PUF60 and its relationship with clinical characteristics were analyzed by multiple database analysis and immunohistochemistry. Phenotypic effects of PUF60 on ovarian cancer cell proliferation and metastasis were examined by in vitro cell proliferation assay, migration assay, and in vivo xenograft models and lung metastasis models. RNA immunoprecipitation, seahorse analyses, RNA stability assay were used to study the effect of PUF60 on the stability of oxidative phosphorylation (OXPHOS)-related genes in OC. RESULTS: We report PUF60 is highly expressed in OC with frequent amplification of up to 33.9% and its upregulation predicts a poor prognosis. PUF60 promotes the proliferation and migration of OC cells both in vitro and in vivo. Mechanistically, we demonstrated that silencing of PUF60 enhanced the stability of mRNA transcripts involved in OXPHOS and decreased the formation of processing bodies (P-bodies), ultimately elevating the OXPHOS level. CONCLUSION: Our study unveils a novel function of PUF60 in OC energy metabolism. Thus, PUF60 may serve as a novel target for the treatment of patients with OC.

Crosstalk of RNA Adenosine Modification-Related Subtypes, Establishment of a Prognostic Model, and Immune Infiltration Characteristics in Ovarian Cancer.

Background: Four RNA adenosine modifications, including m6A, m1A, alternative polyadenylation, and adenosine-to-inosine RNA editing, have been identified as potentially valuable in influencing colorectal carcinogenesis, immune infiltration, and response to drug therapy. However, the regulatory mechanisms and clinical significance of these four RNA modifications in ovarian cancer (OC) remain unknown. Methods: We comprehensively described the transcriptional and genetic modifications of 26 RNA modification "writers" in OC and assessed the expression patterns. We identified two RNA modification subtypes using an unsupervised clustering approach. Subsequently, using differentially expressed genes (DEGs) in both subtypes, we calculated RNA modification "writer" scores (RMW scores) to characterize the RNA modifications of single OC patients. RMW score-related gene expression was investigated by qRT-PCR. We explored the correlation between RMW score and clinical features, immune infiltration, and drug sensitivity. We drew a nomogram to more intuitively and accurately describe the application value of the RMW score. Results: We found that molecular alterations in "writers" are strongly related to prognostic and immune-infiltrating features in OC patients. We identified two different clusters of RNA modifications. According to the immune infiltration characteristics in the two RNA modification isoforms, cluster A and cluster B can correspond to "hot" and "cold" tumors, respectively. With the median RMW score, we classified the patients into high- and low-score subgroups. A low RMW score was associated with good patient prognosis and lower immune infiltration. In addition, a low RMW score equated with a higher cancer stem cell index and a lower tumor mutation burden, which to some extent affected the sensitivity of patients to therapeutic drugs. Seven RMW score-related gene expressions were investigated by qRT-PCR in three OC cell lines. Compared to previously known models, our established RMW score has higher accuracy in predicting patient survival. Conclusion: A comprehensive analysis of four RNA modification patterns in OC reveals their potential value in OC prognosis, immune microenvironment, and drug sensitivity. These results could deepen our knowledge of RNA modification and yield fresh insights for new personalized therapeutic strategies.

High LIN28A and PLK4 co­expression is associated with poor prognosis in epithelial ovarian cancer.

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy. LIN28 homolog A (LIN28A) is a RNA­binding protein, which serves a fundamental role in cell development and pluripotency. Polo­like kinase 4 (PLK4) is a member of the polo­like kinase family, which primarily takes part in the mitotic regulation. Overexpression of LIN28A has been demonstrated in ovarian cancer; however, the expression of PLK4 and the correlation between the expression of LIN28A and PLK4 in EOC has not been discussed. In the present study, the mRNA and protein levels of LIN28A and PLK4 were evaluated by reverse transcription­quantitative polymerase chain reaction and immunohistochemistry in ovarian tissues of patients. Results demonstrated significantly increased expression in EOC compared with benign epithelial ovarian tumors. High expression of LIN28A and PLK4 was detected at the advanced pathological stage. Furthermore, PLK4 expression was positively correlated with LIN28A (r=0.555; P=0.039). The median survival analysis of patients with EOC with LIN28A and PLK4 double positive expression was 14 months, compared with 30 months in single positive and 60 months in double negative patients by Kaplan­Meier analysis (P<0.05). The expressions of LIN28A and PLK4 was elevated in different EOC cell lines compared to with a normal ovarian cell line. The 293T cells transfected with LIN28A plus a PLK4 plasmid were the fastest­growing group. These results suggest that co­expression of LIN28A and PLK4 may be associated with poor prognosis of EOC and could serve as promising prognostic biomarkers and therapeutic targets in EOC. LIN28A and PLK4 may be used along with traditional morphological and clinical characteristics for predicting prognosis.