Expression of NEAT1 can be used as a predictor for Dex resistance in multiple myeloma patients

OBJECTIVE

Multiple myeloma is a heterogeneous disorder and the intratumor genetic heterogeneity contributes to emergency of drug resistance. Dexamethasone has been used clinically for decades for MM. Nevertheless, their use is severely hampered by the risk of developing side effects and the occurrence of Dex resistance. LncRNA NEAT1 plays a oncogenic role and participates in drug resistance in many solid tumors. Therefore, we investigated a potential usefulness of this molecular as a biomarker for diagnosis of MM and possible correlations of NEAT1 expression with drug resistance and prognosis.

METHODS

Bone marrow and peripheral blood mononuclear cells samples were collected from 60 newly diagnosed MM patients. The expression of NEAT1expression level were detected by quantitative real-time PCR analyses. The relationship about the expression levels of lncRNA with other clinical and cytogenetic features was analyzed. In addition, we measured to analysis the correlation between the expression of NEAT1 and Dex resistance in MM patients.

RESULTS

It was found that the expression of NEAT1 is significantly higher in multiple myeloma patients compared to controls and does not change with other clinical features and cytogenetic features. We further discovered that overexpression of NEAT1 was associated with Dex resistance and a poor prognosis in MM patients.

CONCLUSION

LncRNA NEAT1 has a significant value that might act as a promoting factor in the development of MM and may be severed as a diagnostic factor in MM. NEAT1 invovled in Dex resistance, which provide a new interpretation during the chemotherapy for MM.

Myeloid cell leukemia 1 (MCL-1): Structural characteristics and application in cancer therapy

Apoptosis, a major hallmark of cancer cells, regulates cellular fate and homeostasis. BCL-2 (B-cell CLL/Lymphoma 2) protein family is popularly known to mediate the intrinsic mode of apoptosis, of which MCL-1 is a crucial member. Myeloid cell leukemia 1 (MCL-1) is an anti-apoptotic oncoprotein and one of the most investigated members of the BCL-2 family. It is commonly known to be genetically altered, aberrantly overexpressed, and primarily associated with drug resistance in various human cancers. Recent advancements in the development of selective MCL-1 inhibitors and evaluating their effectiveness in cancer treatment establish its popularity as a molecular target. The overall aim is the selective induction of apoptosis in cancer cells by using a single or combination of BCL-2 family inhibitors. Delineating the precise molecular mechanisms associated with MCL-1-mediated cancer progression will certainly improve the efficacy of clinical interventions aimed at MCL-1 and hence patient survival. This review is structured to highlight the structural characteristics of MCL-1, its specific interactions with NOXA, MCL-1-regulatory microRNAs, and at the same time focus on the emerging therapeutic strategies targeting our protein of interest (MCL-1), alone or in combination with other treatments.

Increased MCL-1 expression predicts poor prognosis and disease recurrence in acute myeloid leukemia

Background: Altered expression of the BCL-2 family member MCL-1 has been linked to the progression and outcome of various malignancies. Recently, MCL-1 inhibitor S63845 was reported to kill MCL-1-dependent cancer cells and has potential value in clinical application. Purpose: Herein, we reported MCL-1 expression pattern in Chinese de novo acute myeloid leukemia (AML) and its impact on prognosis and may provide theoretical basis for AML patients using MCL-1 inhibitor in clinics. Real-time quantitative PCR was carried out to detect the transcript of MCL-1 in AML patients. Results: MCL-1 expression was significantly up-regulated in AML compared with controls (P=0.042). We divided the patients into two groups (higher and lower expression of MCL-1) based on the median level. Among both non-acute promyelocytic leukemia (APL) and cytogenetically normal AML (CN-AML), patients with higher expression of MCL-1 correlated with lower complete remission (CR) rate (P=0.031 and 0.004, respectively) and shorter overall survival (OS) time (P=0.008 and 0.004, respectively) compared with those with lower expression of MCL-1. Meanwhile, Cox regression analyses revealed that overexpression of MCL-1 acted as an independent risk factor for OS in non-APL patients and CN-AML patients (P=0.011 and 0.045, respectively). In follow-up patients, MCL-1 expression level decreased after CR compared with newly diagnosis time (P=0.020) and increased after relapse (P=0.004). Conclusion: Our findings suggest that higher expression of MCL-1 predicts poor prognosis and can be used for disease monitoring.

MCL1 gene co-expression module stratifies multiple myeloma and predicts response to proteasome inhibitor-based therapy

Multiple myeloma (MM) is the second most common hematologic cancer, characterized by abnormal accumulation of plasma cells in the bone marrow. The extensive biological and clinical heterogeneity of MM hinders effective treatment and etiology research. Several molecular classification systems of prognostic impact have been proposed, but they do not predict the response to treatment nor do they correlate to plasma cell development pathways. Here we describe the classification of MM into two distinct subtypes based on the expression levels of a gene module coexpressed with MCL1 (MCL1-M), a regulator of plasma cell survival. The classification system enabled prediction of the prognosis and the response to bortezomib-based therapy. Moreover, the two MM subtypes were associated with two different plasma cell differentiation pathways (enrichment of a preplasmablast signature versus aberrant expression of B cell genes). 1q gain, harboring 63 of the 87 MCL1-M members including MCL1, was found in about 80% of the MM with upregulated MCL1-M expression. Clonal analysis showed that 1q gain tended to occur as an early clonal event. Members of MCL1-M captured both MM cell-intrinsically acting signals and the signals regulating the interaction between MM cells with bone marrow microenvironment. MCL1-M members were co-expressed in mouse germinal center B cells. Together, these findings indicate that MCL1-M may play previously inadequately recognized, initiating role in the pathogenesis of MM. Our findings suggest that MCL1-M signature-based molecular clustering of MM constitutes a solid framework toward understanding the etiology of this disease and establishing personalized care. Article Summary: A pathogenic mechanism-guided molecular classification would facilitate treatment decision and etiology research of multiple myeloma. On the basis of the expression levels of a gene module coexpressed with MCL1, we have established a classification scheme assigning multiple myeloma into two subtypes with distinct prognosis, treatment responses and pathogenic backgrounds.

Involvement of miR-29b signaling in the sensitivity to chemotherapy in patients with ovarian carcinoma

Although the molecular mechanisms driving chemoresistance and relapse of ovarian cancer have been widely studied, the key molecules have not been identified. In this study, the expression of miR-29b messenger RNA (mRNA) and its targeted genes, myeloid cell leukemia sequence 1, mitogen-activated protein kinase 10 (MAPK10), and autophagy-related protein 9A (ATG9A), were investigated in ovarian carcinomas, and their associations with clinicopathological characteristics and survival of patients with ovarian cancer were analyzed. The protein expression of MCL1, MAPK10, and ATG9A was measured using immunohistochemistry. miR-29b mRNA and ATG9A gene mRNA levels were measured by real-time polymerase chain reaction. Results demonstrated that the percentage of MCL1, MAPK10, and ATG9A protein-positive cases were significantly higher, whereas miR-29b was significantly lower in ovarian serous, mucinous, and clear cell carcinomas than that in normal tissues. MAPK10 was significantly associated with higher histopathologic grading. The percentage of positive myeloid cell leukemia sequence 1, ATG9A, and MAPK10 protein expression and low miR-29b mRNA expression were significantly higher in cases with clinical stage III and IV ovarian cancer than in cases with clinical stage II ovarian cancer. High ATG9A protein and low miR-29b mRNA expression were significantly associated with relapse. Univariate Kaplan-Meier analysis showed a negative correlation between MAPK10 or ATG9A protein expression and overall as well as progression-free survival, whereas a positive correlation was observed between miR-29b mRNA expression and overall as well as progression-free survival. Multivariate Cox regression analysis showed that elevated MAPK10 or ATG9A protein and lowered miR-29b mRNA expression in ovarian carcinoma was an independent poor prognostic predictor. Our study suggested that miR-29b mRNA, MAPK10 protein expression, and ATG9A protein expression are closely related to chemosensitivity of ovarian carcinoma.