Lnc NEAT1/miR-29b-3p/Sp1 form a positive feedback loop and modulate bortezomib resistance in human multiple myeloma cells

Acquired Bortezomib Resistance in Multiple Myeloma: From Mechanisms to Strategy

OPINION STATEMENT

Multiple myeloma (MM) is a heterogeneous plasma cell tumor with a survival period of several months to over ten years. Despite the development of various new drugs, MM is still incurable and recurs repeatedly. Bortezomib, a landmark event in the history of MM treatment, has dramatically improved the prognosis of patients with MM. Although proteasome inhibitors (PIs) represented by bortezomib, have greatly prolonged MM survival, unfortunately, almost all MM will develop bortezomib resistance, leading to relapse with a shorter survival. It has been reported that both the tumor microenvironment and myeloma cells drive bortezomib resistance. Multiple treatment methods have been attempted to overcome bortezomib resistance, but unfortunately, there has been no breakthrough. It is believed that the key resistance mechanism has not yet been discovered. A deeper understanding of the mechanism of bortezomib resistance and strategies to overcome it can help identify key resistance mechanisms and further improve the prognosis of MM.

The role of lncRNA NEAT1 in human cancer chemoresistance

Chemotherapy is currently one of the most effective methods in clinical cancer treatment. However, chemotherapy resistance is an important reason for poor chemotherapy efficacy and prognosis, which has become an urgent problem to be solved in the field of cancer chemotherapy. Therefore, it is very important to deeply study and analyze the mechanism of cancer chemotherapy resistance and its regulatory factors. Long non-coding RNA nuclear paraspeckle assembly transcript 1 (LncRNA NEAT1) has been shown to be closely associated with chemotherapy resistance in cancer. NEAT1 induces cancer cell resistance to chemotherapeutic drugs by regulating cell apoptosis, cell cycle, drug transport and metabolism, DNA damage repair, EMT, autophagy, cancer stem cell characteristics, and metabolic reprogramming. This indicates that NEAT1 may be an important target to overcome chemotherapy resistance and is expected to be a potential biomarker to predict the effect of chemotherapy. This article summarizes the expression characteristics and clinical characteristics of NEAT1 in different cancers, and deeply discusses the regulatory role of NEAT1 in cancer chemotherapy resistance and related molecular mechanisms, aiming to clarify NEAT1 as a new target to overcome cancer chemotherapy resistance and the feasibility of chemotherapy sensitizers, with a view to providing a potential therapeutic direction for overcoming the dilemma of cancer resistance in the future.

Epigenetic Alterations as Vital Aspects of Bortezomib Molecular Action

Bortezomib (BTZ) is widely implemented in the treatment of multiple myeloma (MM). Its main mechanism of action is very well established. BTZ selectively and reversibly inhibits the 26S proteasome. More precisely, it interacts with the chymotryptic site of the 20S proteasome and therefore inhibits the degradation of proteins. This results in the intracellular accumulation of misfolded or otherwise defective proteins leading to growth inhibition and apoptosis. As well as interfering with the ubiquitin-proteasome complex, BTZ elicits various epigenetic alterations which contribute to its cytotoxic effects as well as to the development of BTZ resistance. In this review, we summarized the epigenetic alterations elicited by BTZ. We focused on modifications contributing to the mechanism of action, those mediating drug-resistance development, and epigenetic changes promoting the occurrence of peripheral neuropathy. In addition, there are therapeutic strategies which are specifically designed to target epigenetic changes. Herein, we also reviewed epigenetic agents which might enhance BTZ-related cytotoxicity or restore the sensitivity to BTZ of resistant clones. Finally, we highlighted putative future perspectives regarding the role of targeting epigenetic changes in patients exposed to BTZ.

Liquid extramedullary disease in multiple myeloma strongly predicts a poor prognosis and is associated with bortezomib resistance gene upregulation

BACKGROUND-AIM

Patients with multiple myeloma (MM) relapse with extramedullary disease (EMD) exhibits an aggressive disease course and poor prognostic features. Myelomatous effusion (ME) is a rare subtype of EMD.

METHODS

In this retrospective study, we analyzed the baseline characteristics and therapies of 14 EMD patients relapse with ME and 21 EMD patients relapse without ME.

RESULTS

Patients with ME relapse demonstrated higher concentrations of serum lactate dehydrogenase, a higher fraction in the International Staging System stage III, and poorer event-free survival (EFS) (9.3 vs. 36.57 months; P = 0.0013) and overall survival (OS) (12.06 vs. 42.64 months; P < 0.001). The multivariate analysis showed that the presence of ME (hazard ratio [HR] 12.57; P = 0.003) and lack of autologous hematopoietic stem cell transplantation therapy (HR 4.382; P = 0.014) were predictive factors for poor OS. Using single-cell RNA sequencing, we discovered several bortezomib resistance genes were highly expressed in extramedullary malignant plasma cells.

CONCLUSIONS

The presence of ME strongly predicts a poor prognosis in patients with MM relapse with EMD, and bortezomib resistance genes are highly expressed in extramedullary malignant plasma cells.

Aberrantly expressed long noncoding RNAs as potential prognostic biomarkers in newly diagnosed multiple myeloma: A systemic review and meta-analysis

BACKGROUND

Numerous studies have manifested long noncoding RNAs (lncRNAs) as biomarkers to determine the prognosis of multiple myeloma (MM) patients. Nevertheless, the prognostic role of lncRNAs in MM is still ambiguous. Herein, we performed a meta-analysis to evaluate the predictive value of aberrantly expressed lncRNAs in MM.

METHODS

A systemic literature search was performed in PubMed, EMBASE, Cochrane, and Web of Science databases until October 9, 2021, and the protocol was registered in the PROSPERO database (CRD42021284364). Our study extracted the hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS), progression-free survival (PFS), or event-free survival (EFS). Begg's and Egger's tests were employed to correct publication bias.

RESULT

Twenty-six individual studies containing 3501 MM patients were enrolled in this study. The results showed that aberrant expression of lncRNAs was associated with poor OS and PFS of MM patients. The pooled HRs for univariate OS and PFS were 1.48 (95% CI = 1.17-1.88, p < 0.001) and 1.30 (95% CI = 1.18-1.43, p < 0.001), respectively, whereas the pooled HRs for multivariate OS and PFS were 1.50 (95% CI = 1.16-1.95, p < 0.001) and 1.59 (95% CI = 1.22-2.07, p < 0.001), respectively. Subgroup analysis suggested that MALAT1, TCF7, NEAT1, and PVT1 upregulation were associated with poor OS (p < 0.05), PVT1, and TCF7 upregulation were implicated with worse PFS (p < 0.05), while only TCF7 overexpression was correlated with reduced EFS (p < 0.05). Moreover, the contour-enhanced funnel plot demonstrated the reliability of our current conclusion, which was not affected by publication bias.

CONCLUSION

Aberrantly expressed particular lncRNAs are critical prognostic indicators in long-term survival as well as promising biomarkers in progression-free status. However, different cutoff values and dissimilar methods to assess lncRNA expression among studies may lead to heterogeneity.

MicroRNA-429 Regulates Invasion and Migration of Multiple Myeloma Cells via Bmi1/AKT Pathway

Background: miR-429-mediated progression of multiple myeloma (MM) was studied through mediating B cell-specific Moloney murine leukemia virus integration site 1 (Bmi1)/protein kinase B (AKT) pathway. Methods: miRNA or siRNA was delivered into MM cell lines to alter cellular proliferation, apoptosis, invasion and migration. Measurements of miR-429 and Bmi1 levels were performed. AKT and p-AKT expression change was measured after regulating miR-429. The interaction between miR-429 and Bmi1 was analyzed. Results: miR-429 elevation disrupted proliferation, anti-apoptosis, migration and invasion properties of MM cells, and inactivated AKT pathway. Bmi1 was a targeting partner of miR-429, which was highly expressed in MM. Bmi1 knockdown phenotyped the effects of overexpressed miR-429 on MM cells. AKT agonist SC70 reversed miR-429-regulated inhibition of MM cell growth. Conclusion: miR-429 suppresses the activation of Bmi1/AKT pathway to down-regulate the malignant functions of MM cells.

Current perspectives on interethnic variability in multiple myeloma: Single cell technology, population pharmacogenetics and molecular signal transduction

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This review discusses the emerging single cell technologies and applications in Multiple myeloma (MM), population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction.

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The role(s) of epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of MM are also discussed.

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It is understood that ethnic component acts as a driver of variable response to chemotherapy in different sub-populations globally.

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This review augments our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, myeloma microenvironment at the molecular and cellular level, and developing precision medicine strategies to combat this malignancy.

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The emerging single cell technologies hold great promise for enhancing our understanding of MM tumor heterogeneity and clonal diversity.

Multiple myeloma (MM) is an aggressive cancer characterised by malignancy of the plasma cells and a rising global incidence. The gold standard for optimum response is aggressive chemotherapy followed by autologous stem cell transplantation (ASCT). However, majority of the patients are above 60 years and this presents the clinician with complications such as ineligibility for ASCT, frailty, drug-induced toxicity and differential/partial response to treatment. The latter is partly driven by heterogenous genotypes of the disease in different subpopulations. In this review, we discuss emerging single cell technologies and applications in MM, population pharmacogenetics of MM, resistance to chemotherapy, genetic determinants of drug-induced toxicity, molecular signal transduction, as well as the role(s) played by epigenetics and noncoding RNAs including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) that influence the risk and severity of the disease. Taken together, our discussions further our understanding of genetic variability in ‘myelomagenesis’ and drug-induced toxicity, augment our understanding of the myeloma microenvironment at the molecular and cellular level and provide a basis for developing precision medicine strategies to combat this malignancy.

LncRNAs driving feedback loops to boost drug resistance: sinuous pathways in cancer

Feedback loops mediate signaling pathways to maintain cellular homeostasis. There are two types, positive and negative feedback loops. Both are subject to alterations, and consequently can become pathogenic in the development of diseases such as cancer. Long noncoding RNAs (lncRNAs) are regulators of signaling pathways through feedback loops hidden as the dark regulatory elements yet to be described with great impact on cancer tumorigenesis, development, and drug resistance. Several feedback loops have been studied in cancer, however, how they are regulated by lncRNAs is hardly evident, setting a trending topic in oncological research. In this review, we recapitulate and discuss the feedback loops that are regulated by lncRNAs to promote drug resistance. Furthermore, we propose additional strategies that allow us to identify, analyze and comprehend feedback loops regulated by lncRNAs to induce drug resistance or even to gain insight into novel feedback loops that are stimulated under the pressure of treatment and consequently increase its efficacy. This knowledge will be useful to optimize the therapeutic use of oncological drugs.

LncRNA NEAT1 regulate diffuse large B-cell lymphoma by targeting miR-495-3p/PD-L1 axis

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a common lymphatic tumor in clinic. LncRNAs were reported to play a regulatory role in many cancers, including DLBCL. This study focused on the roles of NEAT1 in DLBCL.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was carried out to detect mRNA expression. StarBase as well as TargetScan was used to predict targeting relationships, which was confirmed by the Dual Luciferase Reporter Assay and RNA pull-down assay. Cell Counting Kit 8 (CCK-8) were applied to measure cell viability. Flow cytometry assay was applied to detect cell apoptosis. Western blotting assay was conduct to determine protein expression. Lactate dehydrogenase (LDH) release assay were applied to evaluated cell cytotoxicity.

RESULTS

NEAT1 was overexpressed in DLBCL patients. Knockdown of NEAT1 reduced the viability while enhanced the apoptosis of tumor cells. However, overexpression of NEAT1 exhibited an opposite effect. miR-495-3p was a target of NEAT1 and was decreased in DLBCL cells. However, inhibiting miR-495-3p reversed the effect of NEAT1 knock-down on DLBCL cells and induced the malignant behaviors of DLBCL cells. Moreover, NEAT1 functioned as a sponge of miR-495-3p to upregulate PD-L1.

CONCLUSION

Our study demonstrated that a NEAT1/miR-495-3p/PD-L1 axis regulated the development of DLBCL. Therefore, NEAT1 may be a potential biomarker for DLBCL.

ceRNA Network of lncRNA/miRNA as Circulating Prognostic Biomarkers in Non-Hodgkin Lymphomas: Bioinformatic Analysis and Assessment of Their Prognostic Value in an NHL Cohort

Research has been focusing on identifying novel biomarkers to better stratify non-Hodgkin lymphoma patients based on prognosis. Studies have demonstrated that lncRNAs act as miRNA sponges, creating ceRNA networks to regulate mRNA expression, and its deregulation is associated with lymphoma development. This study aimed to identify novel circulating prognostic biomarkers based on miRNA/lncRNA-associated ceRNA network for NHL. Herein, bioinformatic analysis was performed to construct ceRNA networks for hsa-miR-150-5p and hsa-miR335-5p. Then, the prognostic value of the miRNA–lncRNA pairs’ plasma levels was assessed in a cohort of 113 NHL patients. Bioinformatic analysis identified MALAT1 and NEAT1 as hsa-miR-150-5p and has-miR-335-5p sponges, respectively. Plasma hsa-miR-150-5p/MALAT1 and hsa-miR335-5p/NEAT1 levels were significantly associated with more aggressive and advanced disease. The overall survival and progression-free survival analysis indicated that hsa-miR-150-5p/MALAT1 and hsa-miR335-5p/NEAT1 pairs’ plasma levels were remarkably associated with NHL patients’ prognosis, being independent prognostic factors in a multivariate Cox analysis. Low levels of hsa-miR-150-5p and hsa-miR-335-5p combined with high levels of the respective lncRNA pair were associated with poor prognosis of NHL patients. Overall, the analysis of ceRNA network expression levels may be a useful prognostic biomarker for NHL patients and could identify patients who could benefit from more intensive treatments.