LINC00337 Regulates KLF5 and Maintains Stem-Cell Like Traits of Cervical Cancer Cells by Modulating miR-145

Multi-omics data reveals novel impacts of human papillomavirus integration on the epigenomic and transcriptomic signatures of cervical tumorigenesis

Integration of human papilloma virus (HPV) DNA into the human genome may progressively contribute to cervical carcinogenesis. To explore how HPV integration affects gene expression by altering DNA methylation during carcinogenesis, we analyzed a multiomics dataset for cervical cancer. We obtained multiomics data by HPV-capture sequencing, RNA sequencing, and Whole Genome Bisulfite Sequencing from 50 patients with cervical cancer. We detected 985 and 485 HPV-integration sites in matched tumor and adjacent paratumor tissues. Of these, LINC00486 (n = 19), LINC02425 (n = 11), LLPH (n = 11), PROS1 (n = 5), KLF5 (n = 4), LINC00392 (n = 3), MIR205HG (n = 3) and NRG1 (n = 3) were identified as high-frequency HPV-integrated genes, including five novel recurrent genes. Patients at clinical stage II had the highest number of HPV integrations. E6 and E7 genes of HPV16 but not HPV18 showed significantly fewer breakpoints than random distribution. HPV integrations occurring in exons were associated with altered gene expression in tumor tissues but not in paratumor tissues. A list of HPV-integrated genes regulated at transcriptomic or epigenetic level was reported. We also carefully checked the candidate genes with regulation pattern correlated in both levels. HPV fragments integrated at MIR205HG mainly came from the L1 gene of HPV16. RNA expression of PROS1 was downregulated when HPV integrated in its upstream region. RNA expression of MIR205HG was elevated when HPV integrated into its enhancer. The promoter methylation levels of PROS1 and MIR205HG were all negatively correlated with their gene expressions. Further experimental validations proved that upregulation of MIR205HG could promote the proliferative and migrative abilities of cervical cancer cells. Our data provides a new atlas for epigenetic and transcriptomic regulations regarding HPV integrations in cervical cancer genome. We demonstrate that HPV integration may affect gene expression by altering methylation levels of MIR205HG and PROS1. Our study provides novel biological and clinical insights into HPV-induced cervical cancer.

MicroRNA-145-5p modulates Krüppel-like factor 5 and inhibits cell proliferation, migration, and invasion in nasopharyngeal carcinoma

Background

In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated.

Results

Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells.

Conclusions

The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00430-9.

The roles of long noncoding RNAs in the regulation of OCT4 expression

OCT4 is a major transcription factor that maintains the pluripotency of stem cells, including embryonic stem cells, induced pluripotent stem cells and cancer stem cells. An increasing number of long noncoding RNAs have been reported to participate in the regulation of OCT4 expression through various mechanisms, including binding with the OCT4 gene promoter to regulate local methylation; promoting chromosomal spatial folding to form an inner ring, thereby aggregating OCT4 cis-acting elements scattered in discontinuous sites of the chromosome; competitively binding microRNAs with OCT4 to upregulate OCT4 expression at the posttranscriptional level; and sharing a promoter with OCT4. Moreover, the transcription of some long noncoding RNAs is regulated by OCT4, and certain long noncoding RNAs form feedback regulatory loops with OCT4. In this review, we summarized the research progress of the long noncoding RNAs involved in the regulation of OCT4 expression.

Cancer stem cells: a major culprit of intra-tumor heterogeneity

Cancer is recognized as a preeminent factor of the world's mortality. Although various modalities have been designed to cure this life-threatening ailment, a significant impediment in the effective output of cancer treatment is heterogeneity. Cancer is characterized as a heterogeneous health disorder that comprises a distinct group of transformed cells to assist anomalous proliferation of affected cells. Cancer stem cells (CSCs) are a leading cause of cancer heterogeneity that is continually transformed by cellular extrinsic and intrinsic factors. They intensify neoplastic cells aggressiveness by strengthening their dissemination, relapse and therapy resistance. Considering this viewpoint, in this review article we have discussed some intrinsic (transcription factors, cell signaling pathways, genetic alterations, epigenetic modifications, non-coding RNAs (ncRNAs) and epitranscriptomics) and extrinsic factors (tumor microenvironment (TME)) that contribute to CSC heterogeneity and plasticity, which may help scientists to meddle these processes and eventually improve cancer research and management. Besides, the potential role of CSCs heterogeneity in establishing metastasis and therapy resistance has been articulated which signifies the importance of developing novel anticancer therapies to target CSCs along with targeting bulk tumor mass to achieve an effective output.

LncRNA SNHG6 facilitates cell proliferation, migration, invasion and EMT by upregulating UCK2 and activating the Wnt/β-catenin signaling in cervical cancer

Cervical cancer is a most prevalent gynecological malignancy around the world. Long non-coding RNAs (lncRNAs) are recognized as crucial players in the cellular activities of diverse cancers including cervical cancer. We aimed to reveal the biological function of lncRNA small nucleolar RNA host gene 6 (SNHG6) in cervical cancer. Our findings illuminated that SNHG6 expression was elevated in cervical cancer tissues and cell lines, and highly expressed SNHG6 was associated with poor outcome in patients with cervical cancer. Moreover, knockdown of SNHG6 repressed cervical cancer development via inhibiting cell proliferation and migration and accelerating cell apoptosis. Further, SNHG6 was a sponge of miR-485-3p and uridine-cytidine kinase 2 (UCK2) was the functional target of miR-485-3p. SNHG6 increased UCK2 expression by binding with miR-485-3p in cervical cancer cells. The rescue experiments showed that SNHG6 contributed to malignant phenotypes of cervical cancer cells by the miR-485-3p/UCK2 axis. Additionally, SNHG6 activated the Wnt/β-catenin pathway to enhance the proliferative and migratory ability of cervical cancer cells. Overall, this work revealed that SNHG6 promoted malignant behaviors of cervical cancer cells by binding with miR-485-3p to regulate UCK2 and activating the Wnt/β-catenin pathway, which may offer a beneficial direction to treat cervical cancer.

SPINT1-AS1 Drives Cervical Cancer Progression via Repressing miR-214 Biogenesis

Accumulating evidences have revealed the dysregulated expressions and critical roles of non-coding RNAs in various malignancies, including cervical cancer. Nevertheless, our knowledge about the vast majority of non-coding RNAs is still lacking. Here we identified long non-coding RNA (lncRNA) SPINT1-AS1 as a novel cervical cancer-associated lncRNA. SPINT1-AS1 was increased in cervical cancer and correlated with advanced stage and poor prognosis. SPINT1-AS1 was a direct downstream target of miR-214, a well-known tumor suppressive microRNA (miRNA) in cervical cancer. Intriguingly, SPINT1-AS1 was also found to repress miR-214 biogenesis via binding DNM3OS, the primary transcript of miR-214. The interaction between SPINT1-AS1 and DNM3OS repressed the binding of DROSHA and DGCR8 to DNM3OS, blocked DNM3OS cleavage, and therefore repressed mature miR-214 biogenesis. The expression of SPINT1-AS1 was significantly negatively correlated with miR-214 in cervical cancer tissues, supporting the reciprocal repression between SPINT1-AS1 and miR-214 in vivo. Through downregulating mature miR-214 level, SPINT1-AS1 upregulated the expression of β-catenin, a target of miR-214. Thus, SPINT1-AS1 further activated Wnt/β-catenin signaling in cervical cancer. Functionally, SPINT1-AS1 drove cervical cancer cellular proliferation, migration, and invasion in vitro, and also tumorigenesis in vivo. Deletion of the region mediating the interaction between SPINT1-AS1 and DNM3OS, overexpression of miR-214, and inhibition of Wnt/β-catenin signaling all reversed the roles of SPINT1-AS1 in cervical cancer. Collectively, these findings identified SPINT1-AS1 as a novel cervical cancer-associated oncogenic lncRNA which represses miR-214 biogenesis and activates Wnt/β-catenin signaling, highlighting its potential as prognostic biomarker and therapeutic target for cervical cancer.

The roles and regulation of the KLF5 transcription factor in cancers

Krüppel‐like factor 5 (KLF5) is a member of the KLF family. Recent studies have suggested that KLF5 regulates the expression of a large number of new target genes and participates in diverse cellular functions, such as stemness, proliferation, apoptosis, autophagy, and migration. In response to multiple signaling pathways, various transcriptional modulation and posttranslational modifications affect the expression level and activity of KLF5. Several transgenic mouse models have revealed the physiological and pathological functions of KLF5 in different cancers. Studies of KLF5 will provide prognostic biomarkers, therapeutic targets, and potential drugs for cancers.

A novel three-long noncoding RNA risk score system for the prognostic prediction of triple-negative breast cancer

Background: Triple-negative breast cancer (TNBC) is characterized by fast tumor increase, rapid recurrence and natural metastasis. We aimed to identify a genetic signature for predicting the prognosis of TNBC. Materials & methods: We conducted a weighted correlation network analysis of datasets from the Gene Expression Omnibus. Multivariate Cox regression was used to construct a risk score model. Results: The multi-factor risk scoring model was meaningfully associated with the prognosis of patients with TBNC. The predictive power of the model was demonstrated by the time-dependent receiver operating characteristic curve and Kaplan-Meier curve, and verified using a validation set. Conclusion: We established a long noncoding RNA-based model for the prognostic prediction of TNBC.