SENEX-mediated CDK4/6 inhibition promotes senescence and confers apoptosis resistance in B-cell non-Hodgkin lymphoma

Background:The primary cause of treatment failure in patients with refractory or relapsed B-cell non-Hodgkin lymphoma(r/r B-NHL)is resistance to current therapies,and therapy-induced senescence(TIS)stands out as a crucial mechanism contributing to tumor drug resistance.Here,we analyzed SENEX/Rho GTPase Activating Protein 18(ARHGAP18)expression and prognostic significance in doxorubicin-induced B-NHL-TIS model and r/r B-NHL patients,investigating its target in B-NHL cell senescence and the effect of combining specific inhibitors on apoptosis resistance in B-NHL-TIS cells.Methods:Raji cells were transfected with the human SENEX shRNA recombinant lentiviral vector(Sh-SENEX)and the empty vector negative(NC)to construct a stable transfection cell line with knockdown of SENEX.Effect of SENEX-silencing on B-NHL-TIS formation,cell function and cell cycle-related pathways was analyzed.Using doxorubicin(DOX)-inducible senescent B-NHL cells combined with the specific cyclin dependent kinase 4/6(CDK4/6)inhibitor Palbociclib to observe that blocking CDK4/6 effects on TIS formation.SENEX expression of 21 B-NHL patients and 8 healthy controls were analyzed by qRT-PCR,and the correlation between its expression and clinical indicators were evaluated.Results:The downregulation of SENEX expression promotes G1-S phase transition and apoptosis while inhibiting cell proliferation,collectively suppressing the formation of TIS in B-NHL.Blockade of CDK4/6 promotes the DOX-induced G1 phase arrest to enhance TIS formation in B-NHL cells which can reverse the regulatory effect of silencing SENEX on B-NHL cell cycle regulation and senescence.The expression levels of SENEX were notably elevated in B-NHL patients compared to healthy controls,and Elevated expression levels of SENEX were associated with poor prognosis of B-NHL patients.Conclusions:SENEX enhances apoptosis resistance in B-NHL by inhibiting CDK4/6,thereby preventing G1-S phase transition and promoting TIS formation.

SENEX gene promotes cell proliferation by activating RB/E2F pathway in diffuse large B-cell lymphoma cells

The present study aimed to clarify the role of SENEX in malignant cell proliferation in diffuse large B-cell lymphoma(DLBCL).22 DLBCL patients(6 newly diagnosed cases,7 cases at complete remission,and 9 relapsed cases)were included in the study.Our results indicated that both SENEX gene and protein were significantly increased in peripheral blood mononuclear cells(PBMCs)and tumor cells of relapsed DLBCL patients,accompanied by overexpression of p21,p16,and phosphorylated retinoblastoma(Rb).Silencing the SENEX gene in a DLBCL cell line caused a significant decrease in cell proliferation and inhibited cell cycle progression in the G1 phase.Phosphorylated Rb and E2F1 were also decreased,and activation of the Rb/E2F1 pathway was obviously suppressed.To conclude,the SENEX gene promotes proliferation in PBMC and tumor cells of DLBCL patients by activating the Rb/E2F1 pathway,in a manner suggesting that increased SENEX expression affects the relapse of DLBCL and may serve as an important target for DLBCL therapy.

CD34^(+)CD38^(-)subpopulation without CD123 and CD44 is responsible for LSC and correlated with imbalance of immune cell subsets in AML

Acute myeloid leukemia(AML)is regarded as a stem cell disease.However,no one unique marker is expressed on leukemia stem cells(LSC)but not on leukemic blasts nor normal hematopoietic stem cells(HSC).CD34^(+)CD38^(-)with or without CD123 or CD44 subpopulations are immunophenotypically defined as putative LSC fractions in AML.Nevertheless,markers that can be effectively and simply held responsible for the intrinsical heterogeneity of LSC is still unclear.In the present study,we examined the frequency of three different LSC subtypes(CD34^(+)CD38^(-),CD34^(+)CD38^(-)CD123^(+),CD34^(+)CD38^(-)CD44^(+))in AML at diagnosis.We then validated their prognostic significance on the relevance of spectral features for diagnostic stratification,immune status,induction therapy response,treatment effect maintenance,and long^(-)term survival.In our findings,high proportions of the above three different LSC subtypes were all significantly characterized with low complete remission(CR)rate,high relapse/refractory rate,poor overall survival(OS),frequent FLT3^(-)ITD mutation,the high level of regulatory T cells(Treg)and monocytic myeloid^(-)derived suppressor cells(M^(-)MDSC).However,there was no significant statistical difference in all kinds of other clinical performance among the three different LSC groups.It was demonstrated that CD34^(+)CD38^(-)subpopulation without CD123 and CD44 might be held responsible for LSC and correlated with an imbalance of immune cell subsets in AML.

Decreased CD10-positive granulocytes for the differential diagnosis of myelodysplastic syndrome

Myelodysplastic syndromes(MDS)are highly heterogeneous myeloid neoplasms,and a large number of patients are difficult to diagnose and classify by blood and bone marrow examination.As a surface marker of granulocyte,studies have shown CD10 can be used to define the degree of granulocyte maturation in MDS patients.However,whether it can be used for differential diagnosis of MDS and other hematological diseases remains inconclusive.To explore the value of CD10 for differential diagnosis of MDS,60 newly diagnosed MDS,20 aplastic anemia(AA)patients,and 35 iron-deficient anemia(IDA)patients were selected for this study.Bone marrow(BM)specimens were processed for surface marker analysis and labeled with pre-conjugated monoclonal antibodies.Stained cells were detected by flow cytometry.Our results indicated that CD10-positive granulocytes were significantly decreased in BM of MDS patients than AA and IDA patients,and the level of CD10-positive mature granulocytes was not associated with the clinical stages of malignancy.Receiver operating characteristic(ROC)areas under the curve(AUC)of CD10-positive granulocytes was 0.86 and 0.85,respectively,in MDS patients than the IDA group and AA group with good specificity and sensitivity.Further,CD10-positive granulocytes were increased after effective treatment.In conclusion,we found the decrease in CD10-positive granulocytes has a differential diagnostic value of MDS.

Myelodysplastic Syndrome Secondary to Multiple Myeloma: A Case Report and Literature Review

Background: With the prolongation of survival in recent years, the accumulation of toxic and side effects of therapeutic drugs and the concomitant drug-related adverse reactions were reported in recent years. However, myelodysplastic syndrome secondary to multiple myeloma is rare. Objective: To improve the understanding of myelodysplastic syndrome secondary to multiple myeloma. Methods: The clinical data of a patient with myelodysplastic syndrome secondary to multiple myeloma after treatment were analyzed, and the related literature was reviewed. Results: A 54-year-old male patient was diagnosed as multiple myeloma in February 2014. After three courses of first-line induction chemotherapy, he achieved complete remission and received two courses of consolidation treatment. After that, he continued to take thalidomide orally. The disease recurred 13 months after complete remission (CR) with 6q+ karyotype change in 37 months. 21q- karyotype change was found in 39 months. The patient was finally diagnosed as treatment-related secondary myelodysplastic syndrome. Due to the poor effect of chemotherapy, the disease continued to deteriorate. Conclusion: In the course of multiple drug treatment, clinicians should pay attention to the changes of molecular genetics and the treatment-related secondary tumor.

Toxoplasmosis-Associated Secondary Hemophagocytic Syndrome: A Case Report and Literature Review

Background: Toxoplasmosis is an extremely rare disease that occurs in the hosts contact with cat and dog frequently. Most human acute infections go unnoticed in immunocompetent individuals, and gradually transformed into chronic infection. However, while host immunity significantly waned, the risk of reactivation of chronic toxoplasma infection is greatly increased. Reactivation of latent toxoplasmic infection often presents with fever, leukopenia, thrombocytopenia, neurological signs and pneumonia. However, for the non-specific clinical and biological signs and its fetal outcome, toxoplasmosis is often misdiagnosed and only revealed at autopsy. Case Presenation: We report a case hospitalized for a week history of cough, anorexia and fatigue with nasal bleeding for a day. After hospitalization, broad-spectrum antibiotherapy was started without a clear diagnosis of infection. Then the patient did a lot of investigations to search the cause of infection, but there were no positive findings. However, an unexpected discovery was detected from peripheral blood smears, shows 1 - 3 μm in diameter, scattered, short and bow like microorganisms on Day 39 of hospitalization. Combined with the medical history and clinical manifestation, toxoplasmosis was diagnosed finally. Unfortunately, secondary hemophagocytic syndrome (HPS) was diagnosed only two days after targeted anti-infection therapy, and the patient died on Day 45 of hospitalization. Conclusions: Patient with unexplained long-term fever and neurological symptoms, interstitial pneumonitis or myocarditis, toxoplasmosis should be positively considered. Only early diagnosis and treatment can increase the possibility of a successful cure and avoid other secondary diseases.

A Case of EBV-Associated Hemophagocytic Lymphohistiocytosis in Adult: Lessons from the Treatment Process

Hemophagocytic lymphohistiocytosis (HLH), which was first described in 1939 by paediatricians Scott and Robb-Smith, is a life-threatening disease. HLH is characterized as cytokine release syndrome which is caused by excessive but non-malignant activation of macrophages and/or histiocytes in bone marrow and other reticuloendothelial systems. EBV-HLH is the most common type of infection-associated HLH, has a high mortality rate without prompt and effective treatment. A previous study showed that the one-year mortality rate of EBV-HLH patients is 75%. Here we report a case of EBV-associated hemophagocytic syndrome in adult, and the lessons from the treatment process. Through this case, we think that for EBV-related HLH, EBV-DNA should also be monitored in addition to hemophagocytosis-related indicators during treatment. In addition, DEP regimen may not be suitable for patients who have received at least partial response, because impaired immunological functioning may lead to EBV and hemophagocytic re-activity.