The effects of miR-1207-5p expression in peripheral blood on cisplatin-based chemosensitivity of primary gallbladder carcinoma

Update on Chemoresistance Mechanisms to First-Line Chemotherapy for Gallbladder Cancer and Potential Reversal Strategies

OBJECTIVE

Gallbladder cancer (GBC) mortality remains high and chemoresistance is increasing. This review consolidates what is known about the mechanisms of chemoresistance to inform and accelerate the development of novel GBC-specific chemotherapies.

METHODS

Studies related to GBC-related chemoresistance were systematically screened in PubMed using the advanced search function. Search terms included GBC, chemotherapy, and signaling pathway.

RESULTS

Analysis of existing studies showed that GBC has poor sensitivity to cisplatin, gemcitabine (GEM), and 5-fluorouracil. DNA damage repair-related proteins, including CHK1, V-SCR, and H2AX, are involved in tumor adaptation to drugs. GBC-specific chemoresistance is often accompanied by changes in the apoptosis and autophagy-related molecules, BCL-2, CRT, and GBCDRlnc1. CD44 + and CD133 + GBC cells are less resistant to GEM, indicating that tumor stem cells are also involved in chemoresistance. In addition, glucose metabolism, fat synthesis, and glutathione metabolism can influence the development of drug resistance. Finally, chemosensitizers such as lovastatin, tamoxifen, chloroquine, and verapamil are able improve the therapeutic effect of cisplatin or GEM in GBC.

CONCLUSIONS

This review summarizes recent experimental and clinical studies of the molecular mechanisms of chemoresistance, including autophagy, DNA damage, tumor stem cells, mitochondrial function, and metabolism, in GBC. Information on potential chemosensitizers is also discussed. The proposed strategies to reverse chemoresistance should inform the clinical use of chemosensitizers and gene-based targeted therapy for this disease.

LncRNA UCC promotes epithelial-mesenchymal transition via the miR-143-3p/SOX5 axis in non-small-cell lung cancer

Long non-coding RNAs (lncRNAs) have been found to play regulatory roles in cancers; for example, UCC was reported to promote colorectal cancer progression. However, the function of UCC in non-small-cell lung cancer (NSCLC) remains unclear. Therefore, mRNA and protein levels were assessed using qPCR and western blots. Cell viability was assessed by colony-formation assays. The interaction between lncRNAs and miRNAs was detected by dual-luciferase reporter and RIP assays. The tumorigenesis of NSCLC cells in vivo was determined by xenograft assays. LncRNA UCC was highly expressed in both NSCLC tissues and cells. Knockdown of UCC expression suppressed the proliferation of NSCLC cells. In addition, a dual-luciferase reporter system and RIP assays showed that UCC specifically bound to miR-143-3p and acted as a sponge of miR-143-3p in NSCLC cells. The miR-143-3p inhibitor rescued the inhibitory effect of sh-UCC on the proliferation of NSCLC cells. Moreover, miR-143-3p and UCC showed opposite effects on the expression of SOX5, which promoted EMT in NSCLC cells. In addition, in a mouse model, knockdown of UCC expression alleviated EMT and NSCLC progression in vivo, which was consistent with the in vitro results. In the current study, we found that UCC induced the proliferation and migration of NSCLC cells both in vitro and in vivo by inducing the expression of SOX5 via miR-143-3p and subsequently promoted EMT in NSCLC.

Knockdown of lncRNA ANRIL suppresses the production of inflammatory cytokines and mucin 5AC in nasal epithelial cells via the miR-15a-5p/JAK2 axis

The incidence of allergic rhinitis (AR) is increasing worldwide. Human nasal epithelial cells (HNECs) are the key cells in the occurrence of AR. Antisense non-coding RNA in the INK4 locus (ANRIL) was discovered to be involved in the progression of AR. However, the mechanism by which ANRIL mediates the progression of AR remains to be determined. The present study aimed to further explore the mechanism by which ANRIL regulates AR. Thereby, HNECs were treated with IL-13 to mimic AR in vitro. The mRNA expression levels of ANRIL, microRNA (miR)-15a-5p, JAK2, mucin 5AC (MUC5AC), granulocyte-macrophage colony-stimulating factor (GM-CSF) and eotaxin-1, and protein expression levels of JAK2, STAT3 and phosphorylated-STAT3 in HNECs were analyzed using reverse transcription-quantitative PCR and western blotting, respectively. ELISAs were used to detect the secretory levels of inflammatory cytokines and mucin in cell supernatants. In addition, a dual luciferase reporter assay was used to confirm the downstream target of ANRIL and the target gene of miR-15a-5p. The results revealed that the secretory levels of eotaxin-1, GM-CSF and MUC5AC were significantly upregulated by IL-13 in the supernatant of HNECs. The expression levels of ANRIL and JAK2 were also upregulated in IL-13-induced HNECs, while the expression levels of miR-15a-5p were downregulated. In addition, ANRIL was identified to bind to miR-15a-5p. The IL-13-induced upregulation of eotaxin-1, GM-CSF and MUC5AC mRNA expression and secretory levels was significantly inhibited by the genetic knockdown of ANRIL, while the miR-15a-5p inhibitor effectively reversed this effect. JAK2 was also discovered to be directly targeted by miR-15a-5p. The overexpression of JAK2 significantly suppressed the therapeutic effect of miR-15a-5p mimics on IL-13-induced inflammation in vitro. In conclusion, the findings of the present study suggested that the genetic knockdown of ANRIL may suppress the production of inflammatory cytokines and mucin in IL-13-treated HNECs via regulation of the miR-15a-5p/JAK2 axis. Thus, ANRIL may serve as a novel target for AR treatment.

Tanshinol inhibits growth of malignant melanoma cells via regulating miR-1207-5p/CHPF pathway

Tanshinol possesses anti-tumor activity in melanoma both in vitro and in vivo, and miR-1207-5p is involved in tumor progression in melanoma. However, whether miR-1207-5p can be affected by tanshinol treatment in melanoma is not clear. The expression levels of miR-1207-5p were detected by RT-qPCR. The validation of the direct target of miR-1207-5p was through dual-luciferase reporter assay and western blotting assay. The cell viability rate was determined using MTT assay and colony formation assay. The cell mobility was assessed using Transwell migration/invasion assay. Downregulation of miR-1207-5p was found in melanoma cell lines and tissues and was associated with tumor stages, presence of ulceration, lymph node metastasis, and poor overall survival rate of melanoma patients. Tanshinol treatment and miR-1207-5p overexpression suppressed melanoma cell growth and cell mobility. Chondroitin polymerizing factor (CHPF) is a direct target of miR-1207-5p. Tanshinol exerted anti-tumor activity to melanoma through the regulation of miR-1207-5p/CHPF signaling. Our study highlighted the potential therapeutic application of tanshinol and miR-1207-5p as a supplement to enhance the effect of the traditional cancer treatment methods against melanoma.

Chemoresistance Mediated by ceRNA Networks Associated With the PVT1 Locus

Competitive endogenous RNA (ceRNA) networks have emerged as critical regulators of carcinogenesis. Their activity is mediated by various non-coding RNAs (ncRNAs), including long non-coding RNAs and microRNAs, which competitively bind to targets, thereby modulating gene expression and activity of proteins. Of particular interest, ncRNAs encoded by the 8q24 chromosomal region are associated with the development and progression of several human cancers, most prominently lncPVT1. Chemoresistance presents a significant obstacle in the treatment of cancer and is associated with dysregulation of normal cell processes, including abnormal proliferation, differentiation, and epithelial-mesenchymal transition. CeRNA networks have been shown to regulate these processes via both direct sponging/repression and epigenetic mechanisms. Here we present a review of recent literature examining the contribution of ncRNAs encoded by the PVT1 locus and their associated ceRNA networks to the development of resistance to common chemotherapeutic agents used to treat human cancers.

miR-1207-5p regulates the sensitivity of triple-negative breast cancer cells to Taxol treatment via the suppression of LZTS1 expression

Taxol-based chemotherapy is a conventional therapeutic approach for the treatment of triple-negative breast cancer (TNBC). However, the insensitivity of TNBC cells to Taxol greatly limits the anticancer effect of the drug and leads to patient mortality. The present study first evaluated the expression levels of microRNA (miR)-1207-5p in human normal breast epithelial MCF-10A cells and TNBC cell lines (MDA-MB-231, MDA-MB-436 and MDA-MB-453). The results revealed that the highest miR-1207-5p level was in MDA-MB-231, which suggested an oncogenic role of miR-1207-5p in TNBC. Therefore, MDA-MB-231 served as the present study's research model in subsequent experiments. The mRNAs that functioned as tumor suppressor factors for miR-1207-5p were then determined. Leucine zipper tumor suppressor gene 1 (LZTS1), which was predicted by TargetScan 6.2 and was supported by the results of a dual luciferase assay, was identified as a target of miR-1207-5p. AntagomiR-1207-5p increased LZTS1 mRNA and protein expressions, enhanced cell growth arrest and cell apoptosis induced by Taxol in MDA-MB-231 cells. Additionally, it was observed that, when compared with Taxol treatment, the combination of Taxol and antagomiR-1207-5p induced a sharp decrease in B-cell lymphoma 2 (Bcl-2) and phosphorylated-protein kinase B expression accompanied by an increase in the Bcl-2-associated X protein expression. Finally, miR-1207-5p expression was significantly increased, while LZTS1 expression was significantly decreased, in TNBC tissues when compared with normal adjacent tissues, and there was a negative correlation between miR-1207-5p and LZTS1 expression. In addition, there was a notable elevation in the expression of miR-1207-5p and a reduction in the expression of LZTS1 in the Taxol non-responsive TNBC tissues when compared with the Taxol-responsive TNBC tissues. The results of the present study suggested that miR-1207-5p may be a promising predictor of sensitivity towards Taxol in TNBC.