Enhancement of myeloma development mediated though myeloma cell-Th2 cell interactions after microbial antigen presentation by myeloma cells and DCs

Increased Expression of SRSF1 Predicts Poor Prognosis in Multiple Myeloma

Background

Multiple myeloma (MM) is a clonal plasma cell disorder which still lacks sufficient prognostic factors. The serine/arginine-rich splicing factor (SRSF) family serves as an important splicing regulator in organ development. Among all members, SRSF1 plays an important role in cell proliferation and renewal. However, the role of SRSF1 in MM is still unknown.

Methods

SRSF1 was selected from the primary bioinformatics analysis of SRSF family members, and then we integrated 11 independent datasets and analyzed the relationship between SRSF1 expression and MM clinical characteristics. Gene set enrichment analysis (GSEA) was conducted to explore the potential mechanism of SRSF1 in MM progression. ImmuCellAI was used to estimate the abundance of immune infiltrating cells between the SRSF1^high and SRSF1^low groups. The ESTIMATE algorithm was used to evaluate the tumor microenvironment in MM. The expression of immune-related genes was compared between the groups. Additionally, SRSF1 expression was validated in clinical samples. SRSF1 knockdown was conducted to explore the role of SRSF1 in MM development.

Results

SRSF1 expression showed an increasing trend with the progression of myeloma. Besides, SRSF1 expression increased as the age, ISS stage, 1q21 amplification level, and relapse times increased. MM patients with higher SRSF1 expression had worse clinical features and poorer outcomes. Univariate and multivariate analysis indicated that upregulated SRSF1 expression was an independent poor prognostic factor for MM. Enrichment pathway analysis confirmed that SRSF1 takes part in the myeloma progression via tumor-associated and immune-related pathways. Several checkpoints and immune-activating genes were significantly downregulated in the SRSF1^high groups. Furthermore, we detected that SRSF1 expression was significantly higher in MM patients than that in control donors. SRSF1 knockdown resulted in proliferation arrest in MM cell lines.

Conclusion

The expression value of SRSF1 is positively associated with myeloma progression, and high SRSF1 expression might be a poor prognostic biomarker in MM patients.

Repurposing Infectious Diseases Vaccines Against Cancer

Vaccines used to prevent infections have long been known to stimulate immune responses to cancer as illustrated by the approval of the Bacillus Calmette-Guérin (BCG) vaccine to treat bladder cancer since the 1970s. The recent approval of immunotherapies has rejuvenated this research area with reports of anti-tumor responses with existing infectious diseases vaccines used as such, either alone or in combination with immune checkpoint inhibitors. Here, we have reviewed and summarized research activities using approved vaccines to treat cancer. Data supporting a cancer therapeutic use was found for 16 vaccines. For 10 (BCG, diphtheria, tetanus, human papillomavirus, influenza, measles, pneumococcus, smallpox, typhoid and varicella-zoster), clinical trials have been conducted or are ongoing. Within the remaining 6, preclinical evidence supports further evaluation of the rotavirus, yellow fever and pertussis vaccine in carefully designed clinical trials. The mechanistic evidence for the cholera vaccine, combined with the observational data in colorectal cancer, is also supportive of clinical translation. There is limited data for the hepatitis B and mumps vaccine (without measles vaccine). Four findings are worth highlighting: the superiority of intravesical typhoid vaccine instillations over BCG in a preclinical bladder cancer model, which is now the subject of a phase I trial; the perioperative use of the influenza vaccine to limit and prevent the natural killer cell dysfunction induced by cancer surgery; objective responses following intratumoral injections of measles vaccine in cutaneous T-cell lymphoma; objective responses induced by human papillomavirus vaccine in cutaneous squamous cell carcinoma. All vaccines are intended to induce or improve an anti-tumor (immune) response. In addition to the biological and immunological mechanisms that vary between vaccines, the mode of administration and sequence with other (immuno-)therapies warrant more attention in future research.

EFFICIENCY OF BONE MARROW PRECURSOR CELL COLONY-FORMING AS A PREDICTOR OF DISEASE COURSE IN PLASMA CELL MYELOMA PATIENTS WITH A HISTORY OF RADIATION EXPOSURE

OBJECTIVE

Assessment of role of the bone marrow colony-forming efficiency in plasma cell myeloma patients at different stages of treatment as a prognostic criterion for the disease course.

MATERIALS AND METHODS

The colony forming efficiency (CFE) was assayed in stage I-II plasma cell myeloma (PCM)patients (n = 37) aged 42-73, namely in patients survived after the Chornobyl NPP accident (n = 21) and persons notexposed to ionizing radiation (n = 16). There were 11 males exposed to ionizing radiation and having got stage I PCM,9 males and 3 females exposed and having got stage II PCM, 3 males and 3 females not exposed and having got stageI PCM, 6 males and 2 females not exposed and having got stage II PCM. Healthy persons (n = 20) were included in thecontrol group.

RESULTS

Number of the bone marrow (BM) granulocyte-macrophage colony-forming units (CFU-GM) in both exposedand not exposed PCM patients depended on a disease stage. CFU-GM was (16.7 ± 1.2) in the stage I PCM patients vs.(11.1 ± 1.1) in the stage II PCM ones both being lower (p < 0.05) compared to control (64.5 ± 2.2). Changes in cluster formation were similar, i.e. (37.7 ± 1.6) and (19.4 ± 1.3) correspondingly in the stage I and stage II PCM patients.Respective values in control were (89.8 ± 3.6). The CFE in stage I and stage II PCM patients at the time of diagnosiswas lower (5.7 ± 1.5 and 2.4 ± 1.1 respectively) vs. control (39.5 ± 1.51, p < 0.05), but has increased in remission upto (29. 6 ± 1.8) and (13.8 ± 1.2) respectively. There was no difference at that between the irradiated and non-irradiated patients. Number of the fibroblast colony-forming units (CFU-F) in the stage I and stage II PCM patients duringdiagnosis, namely (43.9 ± 5.4) and (22.5 ± 3.7), was lower (p < 0.05) vs. control (110.5 ± 4.9). Upon reaching remission the CFU-F value increased significantly (p < 0.05), reaching (87.4 ± 4.2) and (55.6 ± 2.7) correspondingly in thestage I and stage II PCM patients.

CONCLUSION

Dependence of the BM cell CFE on the stage of PCM and presence or absence of remission was established. Prognostic value of the CFE of BM CFU-GM in terms of life span of patients was shown (Ro Spearm = 0.39,p < 0.02), namely in case of CFE > 20 before the polychemotherapy administration the life span of PCM patients wassignificantly longer vs. cases of CFE < 20.

Microbial antigens-loaded myeloma cells enhance Th2 cell proliferation and myeloma clonogenicity via Th2-myeloma cell interaction

Background

Myeloma cells retain B cell functions, considered to be potential antigen presenting cells, yet there is little information regarding promoting Th2 cell proliferation or the direct effects to myeloma on the Th2 cells stimulated by microbial antigens-loaded myeloma cells.

Methods

Mixed lymphocyte reaction was used colorimetric assays via CCK8-kit. Surface molecular expression was performed by flow cytometry, cells sorting using microbeads. The concentrations of cytokines in serum were assessed using an ELISA kit. Clonogenic assay were performed in a methylcellulose culture system. Statistical analysis was assessed using the Student’s t-test or one-way analysis of variance for multiple comparisons test.

Results

The expression of HLA-DR, CD80 and CD40 on RPMI8266 cell membrane surface was upregulated by interaction with interferon-γ and/or Bacillus Calmette-Guerin Vaccine (BCGV). RPMI8266 cells were able to induce the mixed lymphocyte reaction in a dose-dependent fashion. The Th2 ratio induced by RPMI8266 treated by BCGV and interferon-γ (treated-RPMI8266) cells was only slightly greater than by untreated-tumor cells, but the serum IL-4 level secreted by Th2 cells was markedly higher in treated-RPMI8266 cells group. Th2 cells stimulated by treated-myeloma cells could directly promote treated-myeloma cell clonogenicity in a dose-dependent manner. Anti-HLADR IgG2b completely blocked increased of IL-4 secretion by Th2 cells stimulated by treated-myeloma cells, while also blocked enhancing the clonogenicity of treated tumor cells stimulated by MM-Th2 cells.

Conclusions

These results indicate that a novel mechanism of myeloma pathogenesis in myeloma cells could act as an APC to present microbial Ags to Th2 cells, promoting Th2 cell proliferation, consequently facilitating tumor development by close interaction between Th2 myeloma cells. Taken together, the microbial Ag presenting course of MM-Th2-MM interactions—restricted by MHC class-II—may result in tumor development such that all factors involved in the system could have a potential for myeloma therapeutic intervention.