Long Non-coding RNAs in Cisplatin Resistance in Osteosarcoma

Groenlandicine enhances cisplatin sensitivity in cisplatin-resistant osteosarcoma cells through the BAX/Bcl-2/Caspase-9/Caspase-3 pathway

Groenlandicine is a protoberberine alkaloid isolated from Coptidis Rhizoma, a widely used traditional Chinese medicine known for its various biological activities. This study aims to validate groenlandicine's effect on both cisplatin-sensitive and cisplatin-resistant osteosarcoma (OS) cells, along with exploring its potential molecular mechanism. The ligand-based virtual screening (LBVS) method and molecular docking were employed to screen drugs. CCK-8 and FCM were used to measure the effect of groenlandicine on the OS cells transfected by lentivirus with over-expression or low-expression of TOP1. Cell scratch assay, CCK-8, FCM, and the EdU assay were utilized to evaluate the effect of groenlandicine on cisplatin-resistant cells. WB, immunofluorescence, and PCR were conducted to measure the levels of TOP1, Bcl-2, BAX, Caspase-9, and Caspase-3. Additionally, a subcutaneous tumor model was established in nude mice to verify the efficacy of groenlandicine. Groenlandicine reduced the migration and proliferation while promoting apoptosis in OS cells, effectively damaging them. Meanwhile, groenlandicine exhibited weak cytotoxicity in 293T cells. Combination with cisplatin enhanced tumor-killing activity, markedly activating BAX, cleaved-Caspase-3, and cleaved-Caspase-9, while inhibiting the Bcl2 pathway in cisplatin-resistant OS cells. Moreover, the level of TOP1, elevated in cisplatin-resistant OS cells, was down-regulated by groenlandicine both in vitro and in vivo. Animal experiments confirmed that groenlandicine combined with cisplatin suppressed OS growth with lower nephrotoxicity. Groenlandicine induces apoptosis and enhances the sensitivity of drug-resistant OS cells to cisplatin via the BAX/Bcl-2/Caspase-9/Caspase-3 pathway. Groenlandicine inhibits OS cells growth by down-regulating TOP1 level.Therefore, groenlandicine holds promise as a potential agent for reversing cisplatin resistance in OS treatment.

Multiproperty Polyethylenimine-Caged Platinum Nanoclusters Promote Apoptosis of Osteosarcoma Cells via Regulating the BAX-Bcl-2/Caspase-3/PARP Axis

Osteosarcoma, a prevalent primary bone cancer in children, exhibits a poor prognosis due to the high prevalence of drug resistance. The objective of this study was to investigate the potential of fluorescent ultrafine polyethylenimine-coated caged platinum nanoclusters (PEI-Pt NCs) as an antitumor agent in osteosarcoma. The primary focus of this study involved the utilization of osteosarcoma cells (U2-OS and MG-63) and normal control cells (hBMSC) as the primary subjects of investigation. The capacity of PEI-Pt NCs to enter osteosarcoma cells was observed through the implementation of confocal microscopy. The impact of PEI-Pt NCs on migration and proliferation was assessed through the utilization of various methodologies, including the CCK8 assay, Ki-67 immunofluorescence, clone formation assay, transwell assay, and wound healing assay. Furthermore, the influence of PEI-Pt NCs on apoptosis and its underlying mechanism was explored through the implementation of flow cytometry and Western blotting techniques. The PEI-Pt NCs demonstrated the capability to enter osteosarcoma cells, including the nucleus, while also exhibiting fluorescent labeling properties. Furthermore, the PEI-Pt NCs effectively impeded the migration and proliferation of osteosarcoma cells. Additionally, the PEI-Pt NCs facilitated apoptosis by modulating the BAX-Bcl-2/Caspase 3/PARP axis. The novel nanomaterial PEI-Pt NCs possess diverse advantageous capabilities, including the ability to impede cell proliferation and migration, as well as the capacity to modulate the BAX-Bcl-2/Caspase 3/PARP axis, thereby promoting cell apoptosis. Consequently, this nanomaterial exhibits promising potential in addressing the issue of inadequate platinum-based treatment for osteosarcoma.

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer

BACKGROUND

Chemoresistance is one of the major obstacles that lead to poor prognosis in cervical cancer. linc00958 was reported to be an oncogene in cervical cancer. However, its role in mediating chemoresistance remains to be revealed.

PURPOSE

To explore the regulatory mechanisms of linc00958 in cisplatin-resistant cervical cancer cells and further validate in xenograft mice.

METHODS

Online bioinformatic tools were used to conduct the pre-investigation of linc00958/miR-185-5p/RSF-1 and predict the associations between RSF-1 and AKT1/GSK3β/VEGFA in cervical cancer. RT-qPCR measured the RNA expression levels of linc00958/miR-185-5p/RSF-1 in SiHa and SiHa/DDP. Cell survival rates were evaluated by CCK8 methods after cells were exposed to differential concentrations of DDP. Dual-luciferase reporter methods were used to measure luciferase activity. Western blot measured RSF-1 protein and phosphorylated changes of AKT1/GSK3β. Immunofluorescence was employed to observe VEGFA secretion in vitro. Tube formation was applied to evaluate the in-vitro changes of angiogenesis. The SiHa/DDP cells stably transfected with pLKO-sh-NC or pLKO-sh-linc00958 plasmids, were injected into mice, establishing xenograft models. The changes in mice weight and tumor volumes were recorded. H&E staining and Immunohistochemistry (IHC) method was further performed.

RESULTS

linc00958 expression was higher in SiHa/DDP cells. High linc00958 expression was associated with low overall survival. In SiHa/DDP cells linc00958/miR-185-5p/RSF-1 axis inhibited the cellular resistance to cisplatin and suppressed VEGFA and the tube formation through AKT1/GSK3β/VEGFA pathway. The knockdown of linc00958 inhibited RSF-1 and Ki67, curbing tumor growth; it also inhibited VEGFA and CD34, decreasing angiogenesis in mice.

CONCLUSION

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer.

Curcumol Synergizes with Cisplatin in Osteosarcoma by Inhibiting M2-like Polarization of Tumor-Associated Macrophages

Osteosarcoma is the most prevalent bone cancer, and chemotherapy is still an indispensable treatment in its clinical practice. Cisplatin (CDDP) has become the most commonly used agent for osteosarcoma, although the outcomes of CDDP chemotherapy remain unsatisfactory because of frequent resistance. Here, we report on a promising combination therapy where curcumol, a bioactive sesquiterpenoid, enhanced CDDP-induced apoptosis to eradicate osteosarcoma cells, and revealed that M2-like macrophages might be the underlying associated mechanisms. First, we observed that curcumol enhanced the CDDP-mediated inhibition of cell proliferation and augmented the apoptosis in osteosarcoma cell lines. Curcumol contributed to preventing the migration of osteosarcoma cells when combined with CDDP. Moreover, this drug combination showed more potent tumor-growth suppression in the orthotopic transplantation of osteosarcoma K7M2 WT cells. We then estimated chemotherapy-associated drug-resistant genes, including ABCB1, ABCC1 and ABCG2, and found that curcumol significantly reversed the mRNA levels of CDDP-induced ABCB1, ABCC1 and ABCG2 genes in the tumor tissue. Moreover, M2-like macrophages were enriched in osteosarcoma tissues, and were largely decreased after curcumol and CDDP treatment. Taken together, these findings suggest that curcumol inhibits the polarization of M2-like macrophages and could be a promising combination strategy to synergize with CDDP in the osteosarcoma.

Exosomal CTCF Confers Cisplatin Resistance in Osteosarcoma by Promoting Autophagy via the IGF2-AS/miR-579-3p/MSH6 Axis

Cancer-derived exosomes participate in carcinogenesis and progression of cancers, including metastasis and drug-resistance. Of note, CTCF has been suggested to induce drug resistance in various cancers. Herein, we aim to investigate the role of cisplatin- (CDDP-) resistant osteosarcoma- (OS-) derived exosomal CTCF in OS cell resistance to CDDP and its mechanistic basis. Differentially expressed transcription factors, long noncoding RNAs (lncRNAs), miRNAs, and genes in OS were retrieved using bioinformatics approaches. Exosomes were extracted from CDDP-resistant OS cells and then cocultured with parental OS cells, followed by lentiviral transduction to manipulate the expression of CTCF, IGF2-AS, miR-579-3p, and MSH6. We assessed the in vitro and in vivo effects on malignant phenotypes, autophagy, CDDP sensitivity, and tumor formation of OS cells. It was established that CTCF and IGF2-AS were highly expressed in CDDP-resistant OS cells, and the CDDP-resistant OS cell-derived exosomal CTCF enhanced IGF2-AS transcription. CDDP-resistant OS-derived exosomes transmitted CTCF to OS cells and increased CDDP resistance in OS cells by activating an autophagy-dependent pathway. Mechanistically, CTCF activated IGF2-AS transcription and IGF2-AS competitively bound to miR-579-3p to upregulate MSH6 expression. Additionally, the promoting function of exosomal CTCF-mediated IGF2-AS/miR-579-3p/MSH6 in OS cell resistance to CDDP was confirmed in vivo. Taken together, CDDP-resistant OS-derived exosomal CTCF enhanced resistance of OS cells to CDDP via activating the autophagy-dependent pathway, providing a potential therapeutic consideration for OS treatment.

siRNA-mediated silencing of Nanog reduces stemness properties and increases the sensitivity of HepG2 cells to cisplatin

Liver cancer is one of the most lethal cancers having worldwide prevalence. Despite significant progress in cancer therapy, liver cancer-induced mortality is very high. Nanog, as an essential transcription factor modulating cellular multipotency, causes tumor progression, drug resistance, and preserves stemness properties in various tumors such as liver cancer. Thus, this research was conducted to evaluate the impact of combination therapy of Nanog siRNA/cisplatin on the sensitivity of liver cancer cells to this drug. HepG2 cells were transfected with Nanog siRNA and treated with cisplatin, individually and in combination. Then, it was observed that in transfected HepG2 cells, Nanog expression was significantly reduced at mRNA level and also these cells were sensitized to cisplatin. In addition, to assess the impact of Nanog siRNA and cisplatin individually and in combination on cells' viability, migration capacity, apoptosis, and cell cycle progression, the MTT, wound healing, colony formation assay, Annexin V/PI staining, and flow cytometry assays were applied on HepG2 cells, respectively. Also, the quantitive Real-Time PCR was used to check the expression of stemness-associated genes (CD44, CD133, and Sox2), and apoptosis-related genes (caspase-3, 8, 9, BAX and Bcl2) after combination therapy. It is indicated that the combination of Nanog siRNA and cisplatin significantly reduced proliferation, migration, and colony formation ability, as well as increased apoptosis rate, and cell cycle arrest. Also, it is found that the combination of Nanog siRNA and cisplatin down-regulated the expression of stemness-associated genes and up-regulated apoptosis-related genes in HepG2 cells. Hence, it can be suggested that Nanog inhibition in combination with cisplatin is a potential therapeutic strategy for developing new therapeutic approaches for liver cancer.

The role of long non-coding RNA FGD5-AS1 in cancer

Long noncoding RNAs (lncRNAs) refers to a class of RNAs that have at least 200 nucleotides and do not encode proteins, and the relationship between lncRNA and cancer has recently attracted considerable research attention. The lncRNA FGD5-AS1 is a newly discovered lncRNA with a length of 3772 nucleotides. Studies have found that FGD5-AS1 is abnormally highly expressed in many cancer tissues and was closely related to the lymph node metastasis, tumor invasion, survival time, and recurrence rate of various cancers. Mechanistic analyses show that FGD5-AS1 can stabilize mRNA expression by sponging miRNA, which not only induces cancer cell proliferation, metastasis, invasion, and chemoresistance in vitro, but also promotes tumor growth and metastasis in vivo. In addition, FGD5-AS1 can serve as a diagnostic or prognostic marker for a variety of cancers. This review demonstrates the clinical significance of FGD5-AS1 in human cancer and its role in tumorigenesis and tumor progression.

The Roles of Noncoding RNAs in the Development of Osteosarcoma Stem Cells and Potential Therapeutic Targets

Osteosarcoma (OS) is the common bone tumor in children and adolescents. Because of chemotherapy resistance, the OS patients have a poor prognosis. The one reason of chemotherapeutic resistance is the development of cancer stem cells (CSCs). CSCs represent a small portion of tumor cells with the capacity of self-renewal and multipotency, which are associated with tumor initiation, metastasis, recurrence and drug resistance. Recently, noncoding RNAs (ncRNAs) have been reported to critically regulate CSCs. Therefore, in this review article, we described the role of ncRNAs, especially miRNAs, lncRNAs and circRNAs, in regulating CSCs development and potential mechanisms. Specifically, we discussed the role of multiple miRNAs in targeting CSCs, including miR-26a, miR-29b, miR-34a, miR-133a, miR-143, miR-335, miR-382, miR-499a, miR-1247, and let-7days. Moreover, we highlighted the functions of lncRNAs in regulating CSCs in OS, such as B4GALT1-AS1, DANCR, DLX6-AS1, FER1L4, HIF2PUT, LINK-A, MALAT1, SOX2-OT, and THOR. Due to the critical roles of ncRNAs in regulation of OS CSCs, targeting ncRNAs might be a novel strategy for eliminating CSCs for OS therapy.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

Long Non-Coding RNA ANRIL as a Potential Biomarker of Chemosensitivity and Clinical Outcomes in Osteosarcoma

Osteosarcoma has a poor prognosis due to chemo-resistance and/or metastases. Increasing evidence shows that long non-coding RNAs (lncRNAs) can play an important role in drug sensitivity and cancer metastasis. Using osteosarcoma cell lines, we identified a positive correlation between the expression of a lncRNA and ANRIL, and resistance to two of the three standard-of-care agents for treating osteosarcoma-cisplatin and doxorubicin. To confirm the potential role of ANRIL in chemosensitivity, we independently inhibited and over-expressed ANRIL in osteosarcoma cell lines followed by treatment with either cisplatin or doxorubicin. Knocking-down ANRIL in SAOS2 resulted in a significant increase in cellular sensitivity to both cisplatin and doxorubicin, while the over-expression of ANRIL in both HOS and U2OS cells led to an increased resistance to both agents. To investigate the clinical significance of ANRIL in osteosarcoma, we assessed ANRIL expression in relation to clinical phenotypes using the osteosarcoma data from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset. Higher ANRIL expression was significantly associated with increased rates of metastases at diagnosis and death and was a significant predictor of reduced overall survival rate. Collectively, our results suggest that the lncRNA ANRIL can be a chemosensitivity and prognosis biomarker in osteosarcoma. Furthermore, reducing ANRIL expression may be a therapeutic strategy to overcome current standard-of-care treatment resistance.

Downregulated lncRNA GAS5 and Upregulated miR-21 Lead to Epithelial-Mesenchymal Transition and Lung Metastasis of Osteosarcomas

Lung is the primary site of osteosarcoma metastasis, but the underlying genetic or epigenetic factors determining lung metastasis of osteosarcoma are unknown. In this study, we report the status of growth arrest specific 5 (GAS5) in lung metastatic osteosarcomas. GAS5 was generally downregulated in osteosarcoma patients (n = 24) compared to healthy controls (n = 10) and even more so in patients with lung metastatic disease(n = 11) compared to the patients without metastasis (n = 13). We also report a role of miR-21 in GAS5-mediated effects. Downregulation of GAS5 in hFOB 1.19 and U2OS osteosarcoma cells enhanced their migration and invasion, along with an upregulated epithelial–mesenchymal transition (EMT), as evidenced by downregulated E-cadherin and upregulated vimentin, ZEB1, and ZEB2. Downregulation of GAS5 also resulted in a significantly increased expression of miR-21. Moreover, downregulation of such elevated miR-21 was found to reverse the effects of GAS5 silencing. miR-21 was also found to be elevated in osteosarcoma patients with its levels particularly high in patients with lung metastasis. Our observations reveal a possible role of GAS5 and miR-21 in lung metastasis of osteosarcoma, presenting them as novel targets for therapy.