SUZ12 participates in the proliferation of PNH clones by regulating histone H3K27me3 levels

The histone demethylase JMJD1C regulates CPS1 expression and promotes the proliferation of paroxysmal nocturnal haemoglobinuria clones through cell metabolic reprogramming

Paroxysmal nocturnal haemoglobinuria (PNH) is a disorder resulting from erythrocyte membrane deficiencies caused by PIG-A gene mutations. While current treatments alleviate symptoms, they fail to address the underlying cause of the disease-the pathogenic PNH clones. In this study, we found that the expression of carbamoyl phosphate synthetase 1 (CPS1) was downregulated in PNH clones, and the level of CPS1 was negatively correlated with the proportion of PNH clones. Using PIG-A knockout K562 (K562 KO) cells, we demonstrated that CPS1 knockdown increased cell proliferation and altered cell metabolism, suggesting that CPS1 participates in PNH clonal proliferation through metabolic reprogramming. Furthermore, we observed an increase in the expression levels of the histone demethylase JMJD1C in PNH clones, and JMJD1C expression was negatively correlated with CPS1 expression. Knocking down JMJD1C in K562 KO cells upregulated CPS1 and H3K36me3 expression, decreased cell proliferation and increased cell apoptosis. Chromatin immunoprecipitation analysis further demonstrated that H3K36me3 regulated CPS1 expression. Finally, we demonstrated that histone demethylase inhibitor JIB-04 can suppressed K562 KO cell proliferation and reduced the proportion of PNH clones in PNH mice. In conclusion, aberrant regulation of the JMJD1C-H3K36me3-CPS1 axis contributes to PNH clonal proliferation. Targeting JMJD1C with a specific inhibitor unveils a potential strategy for treating PNH patients.

From LncRNA to metastasis: The MALAT1-EMT axis in cancer progression

Cancer is a complex disease that causes abnormal genetic changes and unchecked cellular growth. It also causes a disruption in the normal regulatory processes that leads to the creation of malignant tissue. The complex interplay of genetic, environmental, and epigenetic variables influences its etiology. Long non-coding RNAs (LncRNAs) have emerged as pivotal contributors within the intricate landscape of cancer biology, orchestrating an array of multifaceted cellular processes that substantiate the processes of carcinogenesis and metastasis. Metastasis is a crucial driver of cancer mortality. Among these, MALAT1 (Metastasis-Associated Lung Adenocarcinoma Transcript 1) has drawn a lot of interest for its function in encouraging metastasis via controlling the Epithelial-Mesenchymal Transition (EMT) procedure. MALAT1 exerts a pivotal influence on the process of EMT, thereby promoting metastasis to distant organs. The mechanistic underpinning of this phenomenon involves the orchestration of an intricate regulatory network encompassing transcription factors, signalling cascades, and genes intricately associated with the EMT process by MALAT1. Its crucial function in transforming tumor cells into an aggressive phenotype is highlighted by its capacity to influence the expression of essential EMT effectors such as N-cadherin, E-cadherin, and Snail. An understanding of the MALAT1-EMT axis provides potential therapeutic approaches for cancer intervention. Targeting MALAT1 or its downstream EMT effectors may reduce the spread of metastatic disease and improve the effectiveness of already available therapies. Understanding the MALAT1-EMT axis holds significant clinical implications. Therefore, directing attention towards MALAT1 or its downstream mediators could present innovative therapeutic strategies for mitigating metastasis and improving patient prognosis. This study highlights the importance of MALAT1 in cancer biology and its potential for cutting back on metastatic disease with novel treatment strategies.

[Role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria]

Objective: This study aimed to investigate the role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria (PNH) patients. Methods: A retrospective analysis was conducted on the clinical data and gene sequencing results of 45 patients with classic PNH admitted to the Department of Hematology, Tianjin Medical University General Hospital, from June 2018 to February 2022. MUC4 gene mutations in patients with classic PNH were summarized, and the risk factors for thrombotic events in these patients were analyzed. Additionally, the effects of MUC4 gene mutations on the cumulative incidence and survival of thrombotic events in patients with classic PNH were determined. Results: The detection rate of MUC4 gene mutations in patients with classic PNH who experienced thrombotic events (thrombotic group) was 68.8% (11/16), which was significantly higher than that in the non-thrombotic group [10.3% (3/29) ] (P<0.001). All mutations occurred in exon 2. MUC4 mutation (OR=20.815, P=0.010) was identified as an independent risk factor for thrombotic events in patients with classic PNH. The cumulative incidence of thrombotic events was 78.6% (11/14) in the MUC4 gene mutation group (mutation group) and 16.1% (5/31) in the non-mutation group, showing a statistically significant difference between the two groups (P<0.001). Survival analysis showed a lower overall survival (OS) rate in the thrombotic group compared with that in the non-thrombotic group [ (34.4±25.2) % vs. (62.7±19.3) % ] (P=0.045). The OS rate of patients was (41.7±29.9) % in the mutation group and (59.1±18.3) % in the non-mutation group (P=0.487) . Conclusion: MUC4 gene mutations are associated with an increased incidence of thrombotic events in classic PNH patients, highlighting their role as independent risk factors for thrombosis in this population. These mutations can be considered a novel predictive factor that aids in evaluating the risk of thrombosis in patients with classic PNH.