Long noncoding RNAs (lncRNA) have been found to play critical roles in tumorigenesis and the development of various cancers, including hepatocellular carcinoma (HCC). Metastasis associated with lung adenocarcinoma transcript-1 (MALAT1) has been identified as an oncogene and prognostic biomarker in HCC. Here, we demonstrated that MALAT1 expression was obviously high in sorafenib-resistant HCC cells. Furthermore, knockdown of MALAT1 increased sorafenib sensitivity in nonresponsive HCC cells, whereas forced expression of MALAT1 conferred sorafenib resistance to responsive HCC cells in vitro. In addition, loss/gain-of-function assays revealed that MALAT1 promoted cell proliferation, migration, and epithelial–mesenchymal transition in HCC cells. Mechanistically, MALAT1 regulated Aurora-A expression by sponging miR-140-5p, thus promoting sorafenib resistance in HCC cells. Moreover, MALAT1 inhibition enhanced the antitumor efficacy of sorafenib in vivo. Clinically, we found that MALAT1 expression was negatively correlated with miR-140-5p expression but positively correlated with Aurora-A expression in patients with HCC and that upregulated MALAT1 was closely correlated with poor survival outcomes in patients with HCC. These findings indicated that MALAT1 may be a novel target for prognosis prediction and therapeutic strategies in patients with HCC treated with sorafenib.
The molecular mechanism responsible forHelicobacter pyloriinfection-mediated gastritis and carcinogenesis is not yet clear. Increased evidence suggests that chronic gastritis and elevated gastric epithelial cell (GEC) apoptosis are crucial events during stomach carcinoma transformation. PUMA is a potent proapoptotic Bcl-2 protein and mediates acute tissue injury. In this study, we aimed to investigate the role of PUMA in GEC apoptosis and inflammation induced byH. pyloriinfection. As a result, we found that PUMA expression was elevated in gastritis tissues compared with uninvolved tissues, and it was correlated with the severity of apoptosis and gastritis. In mice,PUMAmRNA and protein were markedly induced in GECs upon induction of gastritis byH. pylori.PUMA-deficient mice were highly resistant to apoptosis and gastritis induced byH. pylori. Furthermore, the transcription factor NF-κB p65 binds toPUMApromoter to activatePUMAtranscription afterH. pyloriinfection. In addition, NF-κB inhibitor could rescueH. pylori-induced apoptosis and gastritis. Finally,H. pylori-induced activation ofp-p65andPUMAwas mediated via Toll-like receptor 2 (TLR2) and blocked inTLR2knockout mice. Taken together, these results verified the pro-inflammatory effect of PUMA inH. pylori-infected gastric tissue. Moreover, TLR2/NF-κB-mediated transcriptional regulation ofPUMAcontributes to the pathogenesis ofH. pylori-infected gastritis.
4 January 2022 in Oxidative Medicine and Cellular Longevity
Background. Neurodegenerative diseases, such as Alzheimer’s disease, and traumatic brain and spinal cord injury (SCI) are prevalent in clinical practice. Inhibition of hyperactive inflammation and proliferation of endogenous neural stem cells (NSCs) is a promising treatment strategy for SCI. Our previous studies demonstrated the beneficial effects of rosiglitazone (Rosi) on SCI, but its roles in inflammation inhibition and proliferation of NSCs are unknown. Methods. SCI in a rat model was established, and the effects of Rosi on motor functions were assessed. The effects of Rosi on NSC proliferation and the underlying mechanisms were explored in details. Results. We showed that Rosi ameliorated impairment of moto functions in SCI rats, inhibited inflammation, and promoted proliferation of NSCs in vivo. Rosi increased ATP production through enhancing glycolysis but not oxidative phosphorylation. Rosi reduced mitophagy by downregulating PTEN‐induced putative kinase 1 (PINK1) transcription to promote NSC proliferation, which was effectively reversed by an overexpression of PINK1 in vitro. Through KEGG analysis and experimental validations, we discovered that Rosi reduced the expression of forkhead box protein O1 (FOXO1) which was a critical transcription factor of PINK1. Three FOXO1 consensus sequences (FCSs) were found in the first intron of the PINK1 gene, which could be potentially binding to FOXO1. The proximal FCS (chr 5: 156680169–156680185) from the translation start site exerted a more significant influence on PINK1 transcription than the other two FCSs. The overexpression of FOXO1 entirely relieved the inhibition of PINK1 transcription in the presence of Rosi. Conclusions. Besides inflammation inhibition, Rosi suppressed mitophagy by reducing FOXO1 to decrease the transcription of PINK1, which played a pivotal role in accelerating the NSC proliferation.
17 May 2021 in Clinical and Translational Oncology
Aims: This study investigates the association between circulating tumor cells (CTCs) and breast cancer metastasis. Methods: A retrospective study was conducted using patients with histologically confirmed breast cancer recruited from the First Affiliated Hospital of Nanjing Medical University during the period of August 2017–October 2020. We used adjusted logistic regression, the random forest algorithm, and sensitivity analysis to study the association between CTC enumeration and tumor metastasis. Further, we performed next-generation sequencing (NGS) on the CTCs obtained from two patients with breast cancer brain metastasis. Results: A total of 41 out of 116 enrolled patients were identified with tumor metastasis. CTC enumeration was significantly higher in patients with liver metastasis than in those without liver metastasis. Patients with CTCs ≥ 5 exhibited a higher risk of tumor metastasis than those with CTCs < 5 in the adjusted model (odds ratios (OR) = 6.25, 95% confidence interval (CI) = 2.63–15.58). The random forest model identified CTC enumeration as a significant metastasis-related variable with the highest mean decrease accuracy and mean decrease Gini score. No significant association was found between CTCs and visceral metastasis with an OR of 1.29 (95% CI = 0.98–2.05, p = 0.232). Upon further investigating organ-specific metastasis, we found that patients with high CTC levels were more likely to develop liver metastasis (OR = 4.87, 95% CI = 1.34–20.17, p = 0.021). The NGS study of CTCs identified a total of 120 indel mutations (e.g., CNGB1, NTSR1, ZG16). The enriched biological processes were mechanoreceptor differentiation and macrophage activation involved in the immune response. The enriched KEGG pathways included focal adhesion, the PI3K-Akt signaling pathway, and microRNAs involved in cancer. Conclusions: Our study revealed that CTCs ≥ 5 are a risk factor for tumor metastasis in breast cancer patients. In addition, we reported that CTCs ≥ 5 might be associated with a higher risk of liver metastasis in patients with metastatic breast cancer. We have provided the mutational profiles of CTCs based on next-generation sequencing.
Pancreatic cancer is associated with a very poor prognosis highlighted by the close association between the disease incidence and mortality. Pancreatic cancer commonly metastasizes to the liver, peripancreas, common bile duct, stomach, duodenum, and retroperitoneum. Conversely, rectal metastasis from pancreatic cancer is extremely rare. We report a rare case of a 75-year-old man with rectal metastasis from a primary pancreatic carcinoma resected 2 years prior. The patient underwent radiotherapy and chemotherapy, but the patient died of increased tumor load. Our understanding of pancreatic cancer has advanced dramatically in the past decade. Distant metastasis should be taken into account when a patient has a medical history of pancreatic adenocarcinoma, even when a rare metastasis site is involved. Histopathological characteristics and immunohistochemical tests are helpful for diagnosis.