Autophagy in combination therapy of temozolomide and IFN-γ in C6-induced glioblastoma: role of non-coding RNAs

Targeting the dual miRNA/BMP2 network: LncRNA H19-mediated temozolomide resistance unveils novel therapeutic strategies in glioblastoma

Background

Long noncoding RNA (lncRNA) is known to not only be involved in various biological processes but also to play a crucial role in chemotherapy resistance. The development of resistance in glioblastoma (GBM) poses a significant challenge in clinical settings. Nonetheless, the mechanisms through which lncRNA contributes to acquired resistance to Temozolomide (TMZ) in GBM patients remain unclear.

Methods

We identified 265 upregulated and 396 downregulated lncRNAs associated with chemoresistance in GBM from the GEO database (GSE100736). Subsequently, we assessed the expression levels of lncRNA H19, hsa-miR-138-5p, hsa-miR-22-3p, and BMP2 mRNA through quantitative polymerase chain reaction (qPCR) in GBM cells and TMZ-resistant GBM cells. Cell viability and proliferation were evaluated using CCK-8 and cell colony formation assays, respectively. Apoptosis was determined through flow cytometry analysis. The impact of gene overexpression and knockdown on cell proliferation and apoptosis was examined via cell transfection experiments. Furthermore, we investigated the influence of lncRNA H19 on tumor development using an in vivo xenograft tumor model.

Results

The upregulation of lncRNA H19 was observed in TMZ-resistant GBM cell lines and tissues, suggesting its involvement in acquired TMZ resistance. Silencing lncRNA H19 restored TMZ sensitivity in resistant GBM cells in vitro. Conversely, overexpression of lncRNA H19 promoted GBM cell proliferation and hindered TMZ-triggered apoptosis, facilitating the acquisition of TMZ resistance. Notably, lncRNA H19 functions as a molecular decoy for hsa-miR-138-5p and hsa-miR-22-3p, and these miRNAs can reverse the acquired TMZ resistance induced by lncRNA H19 in GBM cells. Additionally, BMP2 gene expression is crucial in the lncRNA H19-mediated pathway of acquired TMZ resistance in GBM cells. Knockdown of lncRNA H19 reinstated TMZ sensitivity in vivo, whereas BMP2 overexpression reinstated TMZ resistance.

Conclusion

LncRNA H19 enhances TMZ resistance in glioblastoma through competitive RNA targeting of BMP2.

Therapeutic efficacy to dose-dependent toxicity of Cabazitaxel in C6-induced glioblastoma model of rats

This study was designed to adjust effective chemotherapy doses of cabazitaxel (CBZ) on cognitive behaviors, inflammatory cytokines and oxidative stress parameters, and survival rate in C6-induced GBM of rats. Male Sprague-Dawley rats bearing intra-caudate nucleus (CN) C6 inoculation were randomly divided into nine groups as follows: sham, tumor, Temozolomide (TMZ) vehicle, TMZ, CBZ vehicle, CBZ at doses of 0.5, 1, 2 and 4 mg/kg. Behavioral tests survival rate, histopathology, immunohistochemistry, oxidative stress, and inflammatory cytokines were evaluated. All drug treatments reduced the volume and number of tumor cells dose-dependently and CBZ4 was able to cause the greatest reduction. The %Survival rate of animals using CBZ1 significantly increased compared to other treatment groups. CBZ1 reduced anxiety-like behaviors and increased the balance of the animal with GBM. CBZ1 and CBZ2 groups improved C6-induced learning disabilities. Treatments could ameliorate tumor-induced dysregulation of oxidative stress. TNF-α/IL-10 decreased in the CBZ1 group compared to other treatment groups, which may indicate an improvement in inflammatory balance. Our findings demonstrate that the administration of CBZ at a dosage of 1 mg/kg exerts advantageous impacts on both the survival rate and neurocognitive performance of rats within the GBM model. However, our results showed that CBZ may have toxic effects, especially in a dose of 4 mg/kg.

M2 macrophage-targeting peptide-modified liposomes enhance the uptake and antitumor efficacy of liposomal IFN-γ in mice with C26 colon carcinoma

While liposomes enhance the safety and pharmacokinetic profile of free drugs, they have not significantly improved therapeutic efficacy. To overcome this challenge, targeted depletion of tumor-associated macrophages (TAMs) shows significant potential as an effective antitumor therapy, reducing off-target effects in comparison to non-targeted liposomes. In the context of peptide-mediated targeted cancer therapy, we evaluated the reprogramming activity of IFN-γ liposomes on TAMs, as well as that of IFN-γ liposomes modified with an M2 macrophage-targeting peptide, which binds preferentially to murine anti-inflammatory M2 macrophages/M2-like TAMs. Flow cytometry analysis showed significantly enhanced cellular uptake of m2-peptide-targeted liposomes in J774.1 macrophage cell lines compared to non-targeted liposomes. In BALB/c mice bearing C-26 murine carcinoma, the m2-peptide-targeted liposome groups exhibited significantly higher IFN-γ concentrations compared to non-targeted counterparts within the tumor environment. Furthermore, m2-peptide-targeted F2 liposomes at doses of 25 μg IFN-γ/kg resulted in superior tumor growth inhibition and greater tumor accumulation, indicating the potential of macrophage-targeted therapy in cancer growth inhibition. However, they failed to improve the overall therapeutic efficacy compared to Doxil. This study proposes a combination therapy of m2-peptide-targeted IFN-γ liposomes with successful chemotherapeutic liposomes such as Doxil.

Circular RNAs: Epigenetic regulators of PTEN expression and function in cancer

Epigenetic regulation of gene expression, without altering the DNA sequence, is involved in many normal cellular growth and division events, as well as diseases such as cancer. Epigenetics is no longer limited to DNA methylation, and histone modification, but regulatory non-coding RNAs (ncRNAs) also play an important role in epigenetics. Circular RNAs (circRNAs), single-stranded RNAs without 3' and 5' ends, have recently emerged as a class of ncRNAs that regulate gene expression. CircRNAs regulate phosphatase and tensin homolog (PTEN) expression at various levels of transcription, post-transcription, translation, and post-translation under their own regulation. Given the importance of PTEN as a tumor suppressor in cancer that inhibits one of the most important cancer pathways PI3K/AKT involved in tumor cell proliferation and survival, significant studies have been conducted on the regulatory role of circRNAs in relation to PTEN. These studies will be reviewed in this paper to better understand the function of this protein in cancer and explore new therapeutic approaches.

CircPAN3/miR-221/PTEN axis and apoptosis in myocardial Infarction: Quercetin's regulatory effects

The circular RNA/microRNA/mRNA axis is a new layer of non-coding RNA(ncRNA)-based regulatory gene expression networks upstream of numerous cell signaling pathways. Circular RNAPAN3 (circPAN3) is involved in autophagy, fibrosis and apoptosis which are responsible for the reduction incardiac functional capacityfollowingmyocardial infarction(MI). However, the molecular mechanism of circPAN3 association with apoptosis is unknown. In addition, the relationship between quercetin as a cardioprotective factor in MI and circular RNA-dependent regulatory pathways has not yet been elucidated. MI was induced in Wistar rats using the left anterior descending artery (LAD) ligation method. One day after surgery, quercetin (30 mg/kg) was injected intraperitoneal (IP) every other day for two weeks. The expression of circPAN3 was increased in the MI group (P < 0.05). The increase in circPAN3 was accompanied by a decrease in miR-221 (P < 0.0001), an increase in PTEN (P < 0.0001), and cleaved caspase 3 (P < 0.001). Quercetin effectively reduced the expression of circPAN3 (P < 0.05), PTEN (P < 0.0001), and cleaved caspase 3 (P < 0.001), and increased the expression of miR-221 (P < 0.0001) and the ratio of p-AKT to p-PI3K (P < 0.001). The circPAN3/miR-221/PTEN pathway is an ncRNA-dependent apoptotic pathway in MI cardiac tissue. Quercetin effectively modulated this pathway, resulting in a reduction of cardiac tissue death and improvement in cardiac function after MI. This suggests that the circPAN3/miR-221 axis plays a role in apoptosis in MI, and quercetin can act as a protective candidate by modulating this pathway.