Hypermethylation of the Promoter Region of miR-23 Enhances the Metastasis and Proliferation of Multiple Myeloma Cells via the Aberrant Expression of uPA

Recent advances of miR-23 in human diseases and growth development

MicroRNA (miRNA) is broadly manifested in eukaryotes and serves as a critical function in biological development and disease occurrence. With the rapid advancement of experimental research tools, researchers have discovered functional correlations among different miRNA isoforms and clusters within the same miRNA family. As a highly conserved member in the miR-23-27-24 cluster, miR-23 exhibits different isoforms and participates in various essential development. Although the miR-23-27-24 cluster has overlapping target sites, their differential expression can demonstrate independent biological functions. Furthermore, the untapped effects of miR-23 on organisms, whether as a functional cluster or a single regulator, has not been systematically elucidated yet. In this review article, we analyze the genomic location of miR-23 and its sequence variances among its isoforms or family members while summarizing its regulatory functions in metabolic diseases, immune responses, cardiovascular diseases, cancer, organ development as well as nervous system function. This review highlights the significant role of miR-23 as a biomarker for disease diagnosis and a key regulatory factor in pathogenesis, which can help us comprehend the diverse functions of miRNAs and provide a theoretical reference for the functional differences among miRNA isoforms.

Enhancing antitumor activity of herceptin in HER2-positive breast cancer cells: a novel DNMT-1 inhibitor approach

HER2 antagonists remain the cornerstone of therapy for patients with HER2-positive breast cancer. This study introduces a novel small-molecule inhibitor of DNA methyltransferase 1 (DNMT-1), referred to as DI-1, designed to synergize with HER2 antagonists in treating HER2-positive breast cancer cells. Clinical data reveal a negative correlation between DNMT-1 expression and PTEN levels, and a positive correlation with the methylation rates of PTEN's promoter. In experiments with SKBR3 and BT474 cells, DI-1 effectively reduced the methylation of PTEN's promoter region, thereby upregulating PTEN expression. This upregulation, in turn, enhanced the cells' sensitivity to HER2 antagonists, indicating that DI-1's mechanism involves inhibiting DNMT-1's recruitment to PTEN's promoter region. Consequently, by increasing PTEN expression, DI-1 amplifies the sensitivity of HER2-positive breast cancer cells to treatment, suggesting its potential as a promising therapeutic strategy in this context.

Novel potent molecular glue degraders against broad range of hematological cancer cell lines via multiple neosubstrates degradation

BACKGROUND

Targeted protein degradation of neosubstrates plays a crucial role in hematological cancer treatment involving immunomodulatory imide drugs (IMiDs) therapy. Nevertheless, the persistence of inevitable drug resistance and hematological toxicities represents a significant obstacle to their clinical effectiveness.

METHODS

Phenotypic profiling of a small molecule compounds library in multiple hematological cancer cell lines was conducted to screen for hit degraders. Molecular dynamic-based rational design and cell-based functional assays were conducted to develop more potent degraders. Multiple myeloma (MM) tumor xenograft models were employed to investigate the antitumor efficacy of the degraders as single or combined agents with standard of care agents. Unbiased proteomics was employed to identify multiple therapeutically relevant neosubstrates targeted by the degraders. MM patient-derived cell lines (PDCs) and a panel of solid cancer cell lines were utilized to investigate the effects of candidate degrader on different stage of MM cells and solid malignancies. Unbiased proteomics of IMiDs-resistant MM cells, cell-based functional assays and RT-PCR analysis of clinical MM specimens were utilized to explore the role of BRD9 associated with IMiDs resistance and MM progression.

RESULTS

We identified a novel cereblon (CRBN)-dependent lead degrader with phthalazinone scaffold, MGD-4, which induced the degradation of Ikaros proteins. We further developed a novel potent candidate, MGD-28, significantly inhibited the growth of hematological cancer cells and induced the degradation of IKZF1/2/3 and CK1α with nanomolar potency via a Cullin-CRBN dependent pathway. Oral administration of MGD-4 and MGD-28 effectively inhibited MM tumor growth and exhibited significant synergistic effects with standard of care agents. MGD-28 exhibited preferentially profound cytotoxicity towards MM PDCs at different disease stages and broad antiproliferative activity in multiple solid malignancies. BRD9 modulated IMiDs resistance, and the expression of BRD9 was significant positively correlated with IKZF1/2/3 and CK1α in MM specimens at different stages. We also observed pronounced synergetic efficacy between the BRD9 inhibitor and MGD-28 for MM treatment.

CONCLUSIONS

Our findings present a strategy for the multi-targeted degradation of Ikaros proteins and CK1α against hematological cancers, which may be expanded to additional targets and indications. This strategy may enhance efficacy treatment against multiple hematological cancers and solid tumors.

Pro-oncogene FBI-1 inhibits the ferroptosis of prostate carcinoma PC-3 cells via the microRNA-324-3p/GPX4 axis

Ferroptosis has been characterized as non-apoptotic programmed cell death and is considered a novel strategy for antitumor treatment. The factor that binds to inducer of short transcripts-1 (FBI-1) is an important proto-oncogene playing multiple roles in human malignancies and the development of resistance to therapy. However, the roles of FBI-1 in ferroptosis of endocrine independent prostate carcinoma are still unknown. The results of this study showed that FBI-1 inhibited the ferroptosis of prostate carcinoma PC-3 cells (a typical endocrine-independent prostate carcinoma cell line) via the miR-324-3p/glutathione peroxidase 4 (miR-324-3p/GPX4) axis. Overexpression of FBI-1 enhanced the expression levels of GPX4. In contrast, knockdown of FBI-1 decreased the expression of GPX4 and induced the ferroptosis of PC-3 cells. The miR-324-3p decreased the expression of GPX4 by targeting the 3'-untranslated region of GPX4 to induce ferroptosis. Notably, FBI-1 increased the expression of GPX4 by repressing the levels of miR-324-3p. The transcription of miR-324-3p was mediated by specificity protein 1 (SP1), and FBI-1 repressed the expression of miR-324-3p by repressing the activation of SP1. In clinical specimens, the endogenous levels of FBI-1 were positively associated with Glutathione Peroxidase 4 (GPX4) and negatively related with the expression of miR-324-3p. Therefore, the results indicated that the miR-324-3p/GPX4 axis participates in the FBI-1-mediated ferroptosis of prostate carcinoma cells.

Highlights on the Effects of Non-Coding RNAs in the Osteonecrosis of the Jaw

Osteonecrosis of the jaw is the progressive loss and destruction of bone affecting the maxilla or mandible in patients treated with antiresorptive and antiangiogenic agents without receiving prior radiation therapy. The pathogenesis involves the inflammatory pathway of receptor activator of nuclear factor NF-kB ligand and the macrophage colony-stimulating factor, essential for osteoclast precursors survival and proliferation and acting through its receptor c-Fms. Evidence has shown the role of non-coding RNAs in the pathogenesis of osteonecrosis of the jaw and this finding might be useful in diagnosis since these small RNAs could be considered as biomarkers of apoptotic activity in bone. Interestingly, it has been proved that miR-29 and miR-31-5p, acting on specific targets such as CALCR and RhoA, promote programmed-cell death and consequently the necrosis of bone tissue. Specific long non-coding RNAs, instead, have been detected both at reduced levels in patients with multiple myeloma and osteonecrosis, and associated with suppression of osteoblast differentiation, with consequences in the progression of mandible lesions. Among non-coding genic material, circular RNAs have the capability to modify the expression of specific mRNAs responsible for the inhibition of bisphosphonates activity on osteoclastogenesis.

miR-140-3p enhances the sensitivity of LUAD cells to antitumor agents by targeting the ADAM10/Notch pathway

Background: The Notch pathway, which is related to the drug-resistance of lung adenocarcinoma (LUAD) type of non-small cell lung cancer (NSCLC) cells, is activated by cleavage of Notch proteins mediated by ADAMs, ADAM10 or ADAM17. Methods: In the present study, our results demonstrated that of these two ADAMs, the expression of ADAM10 in clinical samples of the LUAD type of NSCLC was much higher than that of ADAM17, while miR-140-3p - an miRNA that could target ADAM10 - was identified by an online tool: miRDB (miRNA database). The detail function and mechanism of miR-140-3p in regulating the sensitivity of NSCLC cells to antitumor drugs was systematically explored in vitro and in vivo. Results: In A549, a typical NSCLC LUAD cell line, miR-140-3p decreased ADAM10 expression and repressed activation of the Notch pathway by repressing cleavage of Notch proteins. The expression of miR-140-3p was negatively related to ADAM10 in clinical specimens. Nucleocytoplasmic separation/subfraction assays showed that miR-140-3p was able to inhibit the cleavage of Notch protein, and led to the accumulation of Notch intracellular domains (NICD) in the nucleus. Overexpression of miR-140-3p enhanced the sensitivity of A549 cells to antitumor agents by targeting the 3'UTR region of ADAM10 mRNA in both cultured cells and in vivo models. Conclusion: ADAM10 plays a major role in LUAD, and miR-140-3p acts on ADAM10 and inhibits its expression and the cleavage of Notch protein, leading to the inhibition the activity of the Notch pathway, and ultimately upregulating LUAD cell sensitivity to anti- tumor drugs.