Recent studies have emphasized the important prognostic role of long noncoding RNAs (lncRNAs) in various types of cancers. Here we conducted a meta-analysis to investigate whether lncRNA HOXA11-AS can be served as a prognostic biomarker in human cancers. We systematically searched PubMed, Embase, ISI Web of Science, and SCOPUS for relevant studies, to investigate the prognostic significance of HOXA11-AS expression in cancer patients. Odds ratios (ORs) or hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) are pooled to estimate the association between HOXA11-AS expression and clinicopathological parameters or survival of cancer patients. A total of eight eligible studies with 1320 cancer patients were enrolled in our meta-analysis. The results revealed that increased expression level of HOXA11-AS was significantly associated with clinicopathological parameters including more lymph node metastasis (OR = 2.06, 95% CI 1.31–3.25), advanced tumor stage (OR = 4.22, 95% CI 2.60–6.85), as well as poor tumor differentiation (OR = 2.49, 95 CI 1.47–4.20), but not correlated with age (p = 0.101) or gender (p = 0.845). In addition, cancer patients with high HOXA11-AS are prognosed to have shorter OS (pooled HR = 1.86, 95% CI 1.39–2.48) and PFS (pooled HR = 2.47, 95% CI 1.29–4.75). HOXA11-AS overexpression might be a convinced unfavorable prognostic factor that helps the clinical decision-making process.

Myeloid-derived suppressor cells (MDSCs) and cancer stem cells (CSCs) are two important cellular components in the tumor microenvironment, which may modify the cancer phenotype and affect patient survival. However, the crosstalk between MDSCs and multiple myeloma stem cells (MMSCs) are relatively poorly understood. The frequencies of granulocytic-MDSCs (G-MDSCs) in MM patients were detected by flow cytometry and their association with the disease stage and patient survival were analyzed. RT-PCR, flow cytometry, western blot and sphere formation assays were performed to investigate the effects of G-MDSCs, piRNA-823 and DNA methylation on the maintenance of stemness in MM. Then a subcutaneous tumor mouse model was constructed to analyze tumor growth and angiogenesis after G-MDSCs induction and/or piRNA-823 knockdown in MM cells. Our clinical dataset validated the association between high G-MDSCs levels and poor overall survival in MM patients. In addition, for the first time we showed that G-MDSCs enhanced the side population, sphere formation and expression of CSCs core genes in MM cells. Moreover, the mechanism study showed that G-MDSCs triggered piRNA-823 expression, which then promoted DNA methylation and increased the tumorigenic potential of MM cells. Furthermore, silencing of piRNA-823 in MM cells reduced the stemness of MMSCs maintained by G-MDSCs, resulting in decreased tumor burden and angiogenesis in vivo. Altogether, these data established a cellular, molecular, and clinical network among G-MDSCs, piRNA-823, DNA methylation and CSCs core genes, suggesting a new anti-cancer strategy targeting both G-MDSCs and CSCs in MM microenvironment.

N⁶-methyladenosine (m⁶A), as the most pervasive internal modification of eukaryotic mRNA, plays a crucial role in various cancers, but its role in multiple myeloma (MM) pathogenesis has not yet been investigated. In this study, we revealed significantly decreased m⁶A methylation in plasma cells (PCs) from MM patients and showed that the abnormal m⁶A level resulted mainly from upregulation of the demethylase fat mass and obesity-associated protein (FTO). Gain- and loss-of-function studies demonstrated that FTO plays a tumor-promoting and pro-metastatic role in MM. Combined m⁶A and RNA sequencing (RNA-seq) and subsequent validation and functional studies identified heat shock factor 1 (HSF1) as a functional target of FTO-mediated m⁶A modification. FTO significantly promotes MM cell proliferation, migration, and invasion by targeting HSF1/HSPs in a YTHDF2-dependent manner. FTO inhibition, especially when combined with bortezomib (BTZ) treatment, synergistically inhibited myeloma bone tumor formation and extramedullary spread in NOD-Prkdc^em26Cd52il2rg^em26Cd22/Nju (NCG) mice. We demonstrated the functional importance of m⁶A demethylase FTO in MM progression, especially in promoting extramedullary myeloma (EMM) formation, and proposed the FTO-HSF1/HSP axis as a potential novel therapeutic target in MM.

Inherent or acquired resistance to chemotherapeutic drugs is still an obstacle for the treatment of multiple myeloma (MM). MicroRNA dysregulation is related to the development of chemoresistance in cancers. However, its role in chemoresistance of MM is largely unknown. Here we demonstrated that miR-221/222 were upregulated in plasma cells from patients with MM, especially those with relapsed or refractory disease. Moreover, expression levels of miR-221/222 were inversely correlated with dexamethasone (Dex) sensitivity of human MM cell lines. Importantly, we found that Dex induced pro-death autophagy in MM cells and the inhibition of autophagy significantly decreased Dex-induced cell death. Mechanistically, autophagy-related gene 12 (ATG12) was identified as a novel target gene of miR-221/222, and miR-221/222 overexpression inhibited autophagy by directly targeting ATG12 and the p27kip (p27)-mammalian target of rapamycin (mTOR) pathway. Indeed, Dex treatment decreased the expression of miR-221/222, thereby activating the ATG12/p27-mTOR autophagy-regulatory axis and inducing cell death in Dex-sensitive MM cells. Furthermore, both in vitro and in vivo results showed that the inhibitions of miR-221/222 increased the expression of ATG12 and p27 and functionally induced extended autophagy and cell death of MM cells. In conclusion, our findings demonstrated the crucial role of the miR-221/222-ATG12/p27-mTOR autophagy-regulatory axis in Dex resistance of MM, and they suggest potential prediction and treatment strategies for glucocorticoid resistance.

The neutrophil-to-lymphocyte ratio (NLR), a biomarker for systematic inflammation, has been recently identified as a prognostic factor for various types of both solid and hematologic malignancies. Here we conducted an updated dose–response meta-analysis to investigate whether NLR can be served as a prognostic biomarker in diffuse large B cell lymphoma (DLBCL). We systematically searched PubMed, Embase, ISI Web of Science and CNKI for relevant studies. Odds ratios or hazards ratios (HRs) with corresponding 95% confidence intervals (CIs) were pooled to estimate the association between NLR and clinicopathological parameters or survival of cancer patients. Eleven trials with 2515 DLBCL patients were included in the meta-analysis. The results revealed that elevated pretreatment NLR was significantly associated with elder age, advanced Ann Arbor stage, higher incidence rate of B symptoms and bone marrow involvement, and higher lactate dehydrogenase level, etc. Moreover, increased NLR also predicted poorer overall survival (HR 1.826, 95% CI 1.238–2.692) and progression-free survival/event-free survival (PFS/EFS) (HR 1.591, 95% CI 1.124–2.252). And two-stage dose–response meta-analysis revealed non-linear association between increased NLR and risk of mortality in DLBCL patients. DLBCL patients with higher NLR are more likely to have poorer prognosis than those with lower NLR.