Depleting long noncoding RNA HOTAIR attenuates chronic myelocytic leukemia progression by binding to DNA methyltransferase 1 and inhibiting PTEN gene promoter methylation

Long noncoding RNAs (lncRNAs) are known to play a key role in chronic myelocytic leukemia (CML) development, and we aimed to identify the involvement of the lncRNA HOX antisense intergenic RNA (HOTAIR) in CML via binding to DNA methyltransferase 1 (DNMT1) to accelerate methylation of the phosphatase and tensin homolog (PTEN) gene promoter. Bone marrow samples from CML patients and normal bone marrow samples from healthy controls were collected. HOTAIR, DNMT1, DNMT3A, DNMT3B, and PTEN expression was detected. The biological characteristics of CML cells were detected. The relationship among HOTAIR, DNMT1, and PTEN was verified. Tumor volume and weight in mice injected with CML cells were tested. We found that HOTAIR and DNMT1 expression was increased and PTEN expression was decreased in CML. We also investigated whether downregulated HOTAIR or DNMT1 reduced proliferation, colony formation, invasion, and migration and increased the apoptosis rate of CML cells. Moreover, we tested whether low expression of HOTAIR or DNMT1 reduced the volume and weight of tumors in mice with CML. Collectively, the results of this studied showed that depleted HOTAIR demonstrated reduced binding to DNMT1 to suppress CML progression, which may be related to methylation of the PTEN promoter.

Successful recovery of a patient with multiple myeloma from severe coronavirus disease 2019 (COVID-19) pneumonia during the first chemotherapy cycle: A case report

A continuing outbreak of pneumonia associated with the 2019 novel coronavirus (2019-nCoV) was initially described in Wuhan, China in December 2019. Weak and elderly individuals, and those with chronic diseases such as hematological malignancies are prone to develop severe pneumonia. The humoral immunity of patients with multiple myeloma is prevalently low, and their inferior immunity further deteriorates during chemotherapy. For patients with onco-hematological malignancies infected with 2019-nCoV during the first chemotherapy cycle, the clinical treatment experience is lacking. The present study is a report of a 61-year-old patient newly diagnosed with multiple myeloma in the key 2019-nCoV outbreak area, who suffered severe 2019-nCoV pneumonia during the first chemotherapy cycle. The present case report demonstrated that a rapidly progressive and severe form of pneumonia was a specific clinical feature of COVID-19, especially in immunocompromised patients with cancer. The treatment strategy combining timely suspending chemotherapy, early intervention using intravenous immunoglobulin, interferon α inhalation and oral antiviral drugs was effective. Therefore, in the pandemic environment, it is strongly recommend that the risk of 2019-nCoV infection is assessed prior to chemotherapy.

Delayed-phase thrombocytopenia in patients with coronavirus disease 2019 (COVID-19)

Coronavirus disease 2019 (COVID-19) can affect the haematopoietic system. Thrombocytopenia at admission was prevalent, while late-phase or delayed-phase thrombocytopenia (occurred 14 days after symptom onset) is rare. This retrospective, single-centre study screened 450 COVID-19 patients and enrolled 271 patients at the Union Hospital, Wuhan, China, from January 25 to March 9, 2020. COVID-19-associated delayed-phase thrombocytopenia occurred in 11·8% of enrolling patients. The delayed-phase thrombocytopenia in COVID-19 is prone to develop in elderly patients or patients with low lymphocyte count on admission. The delayed-phase thrombocytopenia is significantly associated with increased length of hospital stay and higher mortality rate. Delayed-phase nadir platelet counts demonstrated a significantly negative correlation with B cell percentages. We also provided and described bone marrow aspiration pathology of three patients with delayed-phase thrombocytopenia, showing impaired maturation of megakaryocytes. We speculated that immune-mediated platelet destruction might account for the delayed-phase thrombocytopenia in a group of patients. In addition, clinicians need to pay attention to the delayed-phase thrombocytopenia especially at 3-4 weeks after symptom onset.

LncRNA MAGI2-AS3 inhibits the self-renewal of leukaemic stem cells by promoting TET2-dependent DNA demethylation of the LRIG1 promoter in acute myeloid leukaemia

The presence or absence of cytogenetic mutations is proposed to be responsible for the pathogenesis of acute myeloid leukaemia (AML). However, the current classification system is inadequate to elucidate the molecular heterogeneity of the disease, and therapy failures frequently occur. Leukaemia stem cells (LSCs) initiate and maintain the clonal hierarchy of AML and exhibit properties of self-renewal remaining recalcitrant to conventional chemotherapy. In this study, we identified a novel long non-coding RNA (lncRNA) MAGI2 antisense RNA 3 (MAGI2-AS3) in AML and investigated its functional role in regulating LSCs self-renewal. LSCs were identified by immunoprofiling of CD34⁺ CD123⁺ in AML patients' marrow. MAGI2-AS3 exhibited a poor expression level in LSCs than the normal human haematopoietic stem cells. Lentivirus-mediated upregulation of MAGI2-AS3 or leucine-rich repeats and Ig-like domains 1 (LRIG1) impaired LSCs self-renewal. MAGI2-AS3-overexpressed LSCs acquired the ability of self-renewal following lentivirus-mediated knockdown of LRIG1. Methylation-dependent inhibition of LRIG1 was evident in LSCs. MAGI2-AS3 was found to induce occupancy of TET2 at the LRIG1 promoter. Lentivirus-mediated downregulation of TET2 could impair MAGI2-AS3-mediated elevation of LRIG1 and neutralize the inhibitory effect of MAGI2-AS3 on LSCs self-renewal. In vivo analysis indicated an elevated overall survival of NOD/SCID mice injected with LSCs in the presence of MAGI2-AS3. Altogether, the key findings support the potential of lncRNA MAGI2-AS3 to serve as a novel candidate for the improvement of AML treatment.

Both chronic HBV infection and naturally acquired HBV immunity confer increased risks of B-cell non-Hodgkin lymphoma

Background

Previous studies examining the relationship between hepatitis B virus (HBV) infection and non-Hodgkin lymphoma (NHL) show inconsistent results in different endemic areas. Furthermore, studies evaluating the association between stratified HBV status and NHL with a well-matched case-control design are rare.

Methods

We conducted a 1:2 case-control study enrolling 3502 NHL cases and 7004 controls, and performed an updated meta-analysis evaluating the association between HBV and NHL subtypes.

Results

The HBsAg-negative/anti-HBc-positive/anti-HBs-positive population, implying naturally acquired immunity after infection, had increased B-NHL risk (Adjusted odds ratio (AOR) (95% confidence interval (95% CI)): 2.25 (1.96–2.57)). The HBsAg-positive/HBeAg-positive population, indicating current HBV infection, had high risk of B-NHL (AOR (95% CI): 6.23 (3.95–9.82)). Specifically, for diffuse large B-cell lymphoma (DLBCL), there was no significant difference in HBsAg status between the germinal centre B (GCB) and non-GCB subtypes. Additionally, our meta-analysis showed in a random effects model, HBV-infected individuals had a pooled OR of 2.09 (95% CI 1.76–2.50; P < 0.01) for NHL.

Conclusions

Chronic HBV infection was positively associated with B-NHL in China. However, acquired immunity by natural infection also increased B-NHL risk. Thus, we further speculated that regardless of whether HBsAg was cleared, the infected population had higher risk of B-NHL. Our study might expand our knowledge on tumorogenesis of NHL and thus provides clues for novel treatment strategies.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5718-x) contains supplementary material, which is available to authorized users.