Long noncoding RNA LINC02582 acts downstream of miR-200c to promote radioresistance through CHK1 in breast cancer cells

PVT1 Mediates Cell Proliferation, Apoptosis and Radioresistance in Nasopharyngeal Carcinoma Through Regulating miR-515-5p/PIK3CA Axis

Background

Radioresistance greatly hinders the treatment of nasopharyngeal carcinoma (NPC). Long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been corroborated to participate in diverse cancers, including NPC. Our aim was to investigate the underlying molecular mechanism of PVT1 in NPC radioresistance.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to measure the expression levels of PVT1, microRNA (miR)-515-5p and phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) in NPC tissues and cells. Cell counting kit-8 (CCK8) assay, colony formation assay and flow cytometry assay were employed to detect cell proliferation, radiosensitivity and apoptosis, respectively. The protein levels of Cyclin D1, B-cell lymphoma 2 associated X (Bax), Cleaved-caspase-3, PIK3CA, protein kinase B (AKT) and phosphorylated AKT (p-AKT) in samples were measured by Western blot. The starBase was used to predict the binding sites between miR-515-5p and PVT1 or PIK3CA. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the interaction. Xenograft tumor model was established to investigate the biological role of PVT1 in vivo.

Results

The levels of PVT1 and PIK3CA were upregulated in NPC tissues and cells, opposite to the expression of miR-515-5p. Knockdown of PVT1 inhibited cell proliferation, radioresistance and promoted cell apoptosis in NPC cells. Meanwhile, PVT1 silencing downregulated Cyclin D1, and upregulated Bax and Cleaved-casp-3 in NPC cells after radiotherapy. Besides, miR-515-5p interacted with PVT1 and targeted PIK3CA in NPC cells. Further studies indicated that PVT1 regulated radioresistance via miR-515-5p/PIK3CA axis and modulated the AKT pathway by interacting with miR-515-5p. Moreover, knockdown of PVT1 suppressed tumor growth in vivo.

Conclusion

Downregulation of PVT1 inhibited proliferation, radioresistance and promoted apoptosis by downregulating PIK3CA via sponging miR-515-5p in NPC cells.

circFLT1 and lncCCPG1 Sponges miR-93 to Regulate the Proliferation and Differentiation of Adipocytes by Promoting lncSLC30A9 Expression

Although many circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) have been discovered in adipocytes, their precise functions and molecular mechanisms remain poorly understood. Based on existing circRNA and lncRNA sequencing data of bovine adipocytes, we screened for the differential expression of circFLT1 and lncCCPG1 in preadipocytes and adipocytes and further analyzed their function and regulation during adipogenesis. The overexpression of circFLT1 and lncCCPG1 together facilitated adipocyte differentiation and suppressed proliferation. Computationally, the RNA hybrid showed that circFLT1 and lncCCPG1 had multiple potential binding sites with miR-93. Additionally, luciferase reporting experiments verified that circFLT1 and lncCCPG1 may interact with miR-93. We also demonstrated that overexpressed miR-93 effectively suppresses the expression of lncSLC30A9. Signaling pathway enrichment analysis, luciferase activity assay, and expression analysis revealed that lncSLC30A9 inhibits proliferation by inhibiting the expression of AKT protein and promotes differentiation by recruiting the FOS protein to the promoter of peroxisome proliferator-activated receptor gamma (PPARG). In sum, our results elucidate the regulatory mechanisms of circFLT1 and lncCCPG1 as miR-93 sponges in bovine adipocytes.

Linc-RA1 inhibits autophagy and promotes radioresistance by preventing H2Bub1/USP44 combination in glioma cells

Radiotherapy is one of the standard treatments for glioma patients; however, its clinical efficacy is limited by radioresistance. We identified a mechanism of such resistance mediated by linc-RA1 (radioresistance-associated long intergenic noncoding RNA 1). Linc-RA1 was upregulated in radioresistant glioma cells and glioma tissue samples, compared with radiosensitive cells and nontumor tissues. Linc-RA1 was associated with inferior overall survival and advanced clinical stage of glioma. Linc-RA1 promoted glioma radioresistance in vitro and in vivo. Mechanistically, linc-RA1 stabilized the level of H2B K120 monoubiquitination (H2Bub1) by combining with H2B and inhibiting the interaction between H2Bub1 and ubiquitin-specific protease 44 (USP44), which inhibited autophagy, thus contributing to glioma radioresistance. These results reveal that linc-RA1-mediated autophagy is a key mechanism of radioresistance and is an actionable target for improving radiotherapy efficacy in patients with glioma.

Non-Coding RNAs in Cancer Radiosensitivity: MicroRNAs and lncRNAs as Regulators of Radiation-Induced Signaling Pathways

Radiotherapy is a cancer treatment that applies high doses of ionizing radiation to induce cell death, mainly by triggering DNA double-strand breaks. The outcome of radiotherapy greatly depends on radiosensitivity of cancer cells, which is determined by multiple proteins and cellular processes. In this review, we summarize current knowledge on the role of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in determining the response to radiation. Non-coding RNAs modulate ionizing radiation response by targeting key signaling pathways, including DNA damage repair, apoptosis, glycolysis, cell cycle arrest, and autophagy. Additionally, we indicate miRNAs and lncRNAs that upon overexpression or inhibition alter cellular radiosensitivity. Current data indicate the potential of using specific non-coding RNAs as modulators of cellular radiosensitivity to improve outcome of radiotherapy.

Knockdown of LINC00662 represses AK4 and attenuates radioresistance of oral squamous cell carcinoma

Background

LncRNAs play crucial roles in the development of carcinomas. However, the investigation of LINC00662 in Oral squamous cell carcinoma (OSCC) is still elusive.

Methods

qRT-PCR assay tested the expression levels of LINC00662, hnRNPC and AK4. With exposure to irradiation, CCK-8, colony formation, flow cytometry and western blot experiments, respectively determined the function of LINC00662 in the radiosensitivity of OSCC cells. Then RIP and western blot assays affirmed the interaction between hnRNPC protein and LINC00662 or AK4. Finally, rescue assays validated the regulation mechanism of LINC00662 in the radioresistance of OSCC.

Results

In the present report, LINC00662 was overexpressed in OSCC and its silencing could alleviate radioresistance of OSCC. Furthermore, the interaction between hnRNPC protein and LINC00662 or AK4 was uncovered. Besides, LINC00662 regulated AK4 mRNA stability through binding to hnRNPC protein. To sum up, LINC00662 modulated the radiosensitivity of OSCC cells via hnRNPC-modulated AK4.

Conclusion

The molecular mechanism of the LINC00662/hnRNPC/AK4 axis was elucidated in OSCC, which exhibited a promising therapeutic direction for patients with OSCC.

The network of non-coding RNAs and their molecular targets in breast cancer

Background

Non-coding RNAs are now recognized as fundamental components of the cellular processes. Non-coding RNAs are composed of different classes, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Their detailed roles in breast cancer are still under scrutiny.

Main body

We systematically reviewed from recent literature the many functional and physical interactions of non-coding RNAs in breast cancer. We used a data driven approach to establish the network of direct, and indirect, interactions. Human curation was essential to de-convolute and critically assess the experimental approaches in the reviewed articles. To enrol the scientific papers in our article cohort, due to the short time span (shorter than 5 years) we considered the journal impact factor rather than the citation number.

The outcome of our work is the formal establishment of different sub-networks composed by non-coding RNAs and coding genes with validated relations in human breast cancer. This review describes in a concise and unbiased fashion the core of our current knowledge on the role of lncRNAs, miRNAs and other non-coding RNAs in breast cancer.

Conclusions

A number of coding/non-coding gene interactions have been investigated in breast cancer during recent years and their full extent is still being established. Here, we have unveiled some of the most important networks embracing those interactions, and described their involvement in cancer development and in its malignant progression.

Radiosensitization of Hepatocellular Carcinoma through Targeting Radio-Associated MicroRNA

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related deaths worldwide. For patients who are resistant to monotherapy, multimodal therapy is a basic oncologic principle that incorporates surgery, radiotherapy (RT), and chemotherapy providing survival benefits for patients with most types of cancer. Although liver has low tolerance for radiation, high-precision RT for local HCC minimizes the likelihood of radiation-induced liver disease (RILD) in noncancerous liver tissue. RT have several therapeutic benefits, including the down-staging of tumors to make them resectable and repression of metastasis. The DNA damage response (DDR) is a cellular response to irradiation (IR), including DNA repair of injured cells and induction of programmed cell death, thereby resulting in maintenance of cell homeostasis. Molecules that block the activity of proteins in DDR pathways have been found to enhance radiotherapeutic effects. These molecules include antibodies, kinase inhibitors, siRNAs and miRNAs. MicroRNAs (miRNAs) are short non-coding regulatory RNAs binding to the 3'-untranslated regions (3'-UTR) of the messenger RNAs (mRNAs) of target genes, regulating their translation and expression of proteins. Thus, miRNAs and their target genes constitute complicated interactive networks, which interact with other molecules during carcinogenesis. Due to their promising roles in carcinogenesis, miRNAs were shown to be the potential factors that mediated radiosensitivity and optimized outcomes of the combination of systemic therapy and radiotherapy.

System level characterization of small molecule drugs and their affected long noncoding RNAs

Long noncoding RNAs (lncRNAs) have multiple regulatory roles and are involved in many human diseases. A potential therapeutic strategy based on targeting lncRNAs was recently developed. To gain insight into the global relationship between small molecule drugs and their affected lncRNAs, we constructed a small molecule lncRNA network consisting of 1206 nodes (1033 drugs and 173 lncRNAs) and 4770 drug-lncRNA associations using LNCmap, which reannotated the microarray data from the Connectivity Map (CMap) database. Based on network biology, we found that the connected drug pairs tended to share the same targets, indications, and side effects. In addition, the connected drug pairs tended to have a similar structure. By inferring the functions of lncRNAs through their co-expressing mRNAs, we found that lncRNA functions related to the modular interface were associated with the mode of action or side effects of the corresponding connected drugs, suggesting that lncRNAs may directly/indirectly participate in specific biological processes after drug administration. Finally, we investigated the tissue-specificity of drug-affected lncRNAs and found that some kinds of drugs tended to have a broader influence (e.g. antineoplastic and immunomodulating drugs), whereas some tissue-specific lncRNAs (nervous system) tended to be affected by multiple types of drugs.