MCM3AP-AS1: An Indispensable Cancer-Related LncRNA

ncRNA-mediated SOX4 overexpression correlates with unfavorable outcomes and immune infiltration in hepatocellular carcinoma

BACKGROUND

The activity and number of immune cells in the tumor microenvironment are closely related to the overall survival of patients with hepatocellular carcinoma (HCC). The sex-determining region Y-box 4 (SOX4) gene is abnormally expressed in various tumor tissues and is critical for tumor development. However, the correlation between SOX4 expression in HCC and tumor immunity is unclear.

METHODS

SOX4 expression was explored using data from The Cancer Genome Atlas, and UALCAN databases. Real-time reverse transcription quantitative and western blotting were used to analyze SOX4 expression in several liver cancer cell lines. Additionally, correlations among SOX4 expression, cancer immune characteristics, and infiltrated immune cell gene marker sets in patients with HCC were analyzed using data from the Tumor Immune Estimation Resource, Gene Expression Profiling Interactive Analysis, and Tumor-Immune System Interactions databases. Moreover, we evaluated SOX4 expression in HCC tissues and the correlation of SOX4 expression with survival rate. Subsequently, noncoding RNAs (ncRNAs) responsible for SOX4 overexpression were identified using expression, correlation, and survival analyses.

RESULTS

SOX4 expression was significantly upregulated in HCC and correlated with a poor prognosis. Additionally, SOX4 upregulation in HCC positively correlated with immune cell infiltration, several biomarkers of immune cells, and immune checkpoint expression. Finally, the MCM3AP-AS1/hsa-miR-204-5p axis was identified as the most likely upstream ncRNA-related pathway for SOX4 in HCC. These results indicated that ncRNA-mediated upregulation of SOX4 correlated with the immune infiltration level and poor prognosis in HCC. Our findings provide new directions for the development of novel immunotherapeutic targets for HCC.

Transcription factor FOXF2 promotes the development and progression of pancreatic cancer by targeting MSI2

Pancreatic cancer (PC) is a malignant tumor possessing high mortality. The role of transcription factor Forkhead Box F2 (FOXF2) in PC remains unverified. The current study investigated the roles of FOXF2 in developing PC in vitro and in vivo. A xenograft tumor model was constructed with nude mice injected using FOXF2‑overexpressing PC cells or FOXF2‑silenced PC cells. High FOXF2 expression significantly enhanced the proliferation ability of PC cells in vitro and pancreatic tumor growth in vivo. The cell cycle analysis indicated that transition of G1‑S phase was promoted by FOXF2. The cell cycle‑associated proteins cyclin D1, CDK2, phosphorylated (p)‑CDK2 and p‑RB were upregulated in the FOXF2‑overexpressing cells and downregulated in the cells with FOXF2 knockdown. Flow cytometric analysis and Hoechst staining showed that the percentage of apoptotic cells was significantly increased after FOXF2 was silenced. FOXF2 knockdown promoted expression of pro‑apoptotic proteins (Bad, Bax and cleaved caspase‑3) while suppressing the anti‑apoptotic proteins (Bcl‑2 and Bcl‑xl) at the protein level. FOXF2 improved the migration and invasion of PC cells in vitro. Moreover, luciferase and chromatin immunoprecipitation assays revealed that FOXF2 binds to the MSI2 promoter, promoting its transcriptional expression. FOXF2 knockdown inhibited the MSI2 protein translation while enhancing the translation of NUMB protein, suppressing PC development in vivo. MSI2 silencing reversed the promotive effect mediated by FOXF2 on cell proliferation. These results demonstrated that FOXF2 is essential in PC progression, and the potential mechanism includes regulating MSI2 transcription.

Two Cases of Periodic Paralysis Associated With MCM3AP Variants

OBJECTIVES

Periodic paralysis is a rare genetic condition characterized by episodes of neuromuscular weakness, often provoked by electrolyte abnormalities, physiologic stress, physical exertion, and diet. In addition to mutations in genes coding for skeletal muscle ion channels, in 2019, Gustavasson et al discovered that the MCM3AP gene could be responsible for periodic paralysis. In this study, we present 2 individuals with clinical episodes of periodic paralysis who have variants in the MCM3AP gene.

METHODS

Two unrelated probands were independently evaluated with clinical, genetic, and electrodiagnostic testing.

RESULTS

Proband 1 is a 46-year-old man who presented with decades of ongoing episodic weakness and fatigue, clinically diagnosed with periodic paralysis and supported by electrodiagnostic studies. Proband 2 is a 34-year-old woman with a history of episodic paralysis since childhood. Genetic testing in both individuals revealed potentially pathogenic variants in the MCM3AP gene.

CONCLUSIONS

Periodic paralysis is a condition that significantly affects the lives of those diagnosed. The results illustrate that MCM3AP gene variants can been associated with a clinical and electrodiagnostic presentation of periodic paralysis. Additional future research should focus on clarifying any relationship between these genetic variants and the disease, as well as other possible genetic causes.

Novel Long Noncoding RNAs, LINC01093 and MYLK-AS1, Serve as Potential Diagnostic and Prognostic Biomarkers or Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most fatal human malignancies worldwide. In this research, we aimed to identify long noncoding RNAs (lncRNAs) as biomarkers for HCC diagnosis and prognosis. lncRNA expression profiles were obtained from Gene Expression Omnibus and The Cancer Genome Atlas databases. The differentially expressed lncRNAs between HCC and adjacent tissues were analyzed with bioinformatic tools. Four lncRNAs with area under the curve of the receiver operating characteristic curve >0.9 were selected from both datasets. Univariate and Kaplan-Meier analyses were performed to obtain LINC01093, MYLK-AS1, and MCM3AP-AS1 as the optimal diagnostic and prognostic biomarkers. Finally, qPCR confirmed that LINC01093 and MYLK-AS1 were significantly differentially expressed in HCC and adjacent normal tissues. In general, we demonstrated that novel lncRNAs, LINC01093 and MYLK-AS1, could be used as potential diagnostic and prognostic biomarkers for HCC.

Extracellular vesicles derived from cervical cancer cells carrying MCM3AP-AS1 promote angiogenesis and tumor growth in cervical cancer via the miR-93/p21 axis

Tumor cells can promote angiogenesis by secreting extracellular vesicles (EVs). Meanwhile, tumor-derived EVs can carry long non-coding RNAs to activate pro-angiogenic signaling in endothelial cells. Here, we investigated the role of long non-coding RNA MCM3AP-AS1 carried by cervical cancer (CC) cell-derived EVs in the angiogenesis and the resultant tumor growth in CC, as well as the potential molecular mechanisms. LncRNAs significantly expressed in CC cell-derived EVs and CC were screened, followed by prediction of downstream target genes. EVs were isolated from HcerEpic and CaSki cell supernatants, followed by identification. The expression of MCM3AP-AS1 in CC was analyzed and its interaction with miR-93-p21 was confirmed. Following co-culture system, the role of MCM3AP-AS1 carried by EVs in HUVEC angiogenic ability, CC cell invasion and migration in vitro along with angiogenesis and tumorigenicity in vivo was assayed. MCM3AP-AS1 was overexpressed in CC cell-derived EVs as well as in CC tissues and cell lines. Cervical cancer cell-derived EVs could transfer MCM3AP-AS1 into HUVECs where MCM3AP-AS1 competitively bound to miR-93 and upregulate the expression of the miR-93 target p21 gene. Thus, MCM3AP-AS1 promoted angiogenesis of HUVECs. In the similar manner, MCM3AP-AS1 enhanced CC cell malignant properties. In nude mice, EVs-MCM3AP-AS1 induced angiogenesis and tumor growth. Overall, this study reveals that CC cell-derived EVs may transport MCM3AP-AS1 to promote angiogenesis and tumor growth in CC.

The role of LncRNA MCM3AP-AS1 in human cancer

Long noncoding RNAs (lncRNA) play pivotal roles in every level of gene and genome regulation. MCM3AP-AS1 is a lncRNA that has an oncogenic role in several kinds of cancers. Aberrant expression of MCM3AP-AS1 has been reported to be involved in the progression of diverse malignancies, including colorectal, cervical, prostate, lymphoma, lung, ovary, liver, bone, and breast cancers. It is generally believed that MCM3AP-AS1 expression is associated with cancer cell growth, proliferation, angiogenesis, and metastasis. MCM3AP-AS1 by targeting various signaling pathways and microRNAs (miRNAs) presents an important role in cancer pathogenesis. MCM3AP-AS1 as a competitive endogenous RNA has the ability to sponge miRNA, inhibit their expressions, and bind to different target mRNAs related to cancer development. Therefore, MCM3AP-AS1 by targeting several signaling pathways, including the FOX family, Wnt, EGF, and VEGF can be a potent target for cancer prediction and diagnosis. In this review, we will summarize the role of MCM3AP-AS1 in various human cancers.

Oncogenic roles of LINC01234 in various forms of human cancer

Abnormal expression of long non-coding RNAs (lncRNAs) plays an essential role in various malignant neoplasia. As a newly identified lncRNA, LINC01234 is abnormally expressed in several types of cancers and promotes the development of cancers. Accumulating evidence indicates that overexpression of LINC01234 is associated with poor clinical outcomes. Moreover, LINC01234 modulates many cellular events as a putative proto-oncogene, including proliferation, migration, invasion, apoptosis, cell cycle progression, and EMT. In terms of molecular mechanism, LINC01234 regulates gene expression by acting as ceRNA, participating in signaling pathways, interacting with proteins and other molecules, and encoding polypeptide. It reveals that LINC01234 may serve as a potential biomarker for cancer diagnosis, treatment, and prognosis. This review summarizes the expression pattern, biological function, and molecular mechanism of LINC01234 in human cancer and discusses its potential clinical utility.