Association between tumor necrosis factor alpha gene polymorphisms and multiple myeloma risk: an updated meta-analysis

Evaluation of genetic and epigenetic changes of Tumor Necrosis Factor-Alpha gene in larynx cancer

BACKGROUND

Tumor Necrosis Factor-Alpha (TNF-α) is a proinflammatory cytokine that plays a role in inflammation, which is one of the hallmarks of cancer, and its polymorphic variants have been associated with disease risk in many cancers in the literature. The aim of this study was to investigate four different polymorphic variants, differential methylation and expression status of the TNF-α gene and to determine the associations between these variants and disease risk, and to evaluate the relationship between the results and clinical parameters. We purposed to investigate the genetic and epigenetic alterations of the TNF-α gene in larynx cancer (LC).

MATERIAL AND METHODS

After isolation of DNA/RNA from whole blood, tumor and normal tissue, polymorphic variant alleles differrential expression and methylation levels were analyzed by RFLP, semiquantitative RT-PCR, and restriction enzyme digestion, respectively. TNF-α expression and methylation levels were calculated using BIO1D software. The frequencies of the variants c.-238 G>A (rs361525), c.-857 C>T (rs1799724), c.-863 C>A (rs1800630), and c.-1031 T > C (rs1799964) in the promoter region of TNF-α in LC Turkish patients and healthy individuals were examined using the De-Finetti case-control program. Haplotype frequencies and linkage disequilibrium were analyzed using the SNPStats program.

RESULTS

The frequency of genotype c.-1031 T > C was significantly lower in patients than in healthy individuals [TT vs TC: OR (%95CI) = 7.00 (1.75-27.93), p = 0.003, χ2 = 8.76]. The heterozygous variant of - 857 was associated with recurrence [T vs G: OR (%95CI) = 0.15 (0.02-0.95), p = 0.02, χ2 = 4.86]. For c.-238 G>A, c.-857 C>T, and c.-863 C>A, there was no statistically significant difference between the patient and healthy group in terms of disease risk. A significant association was found between c.-1031 T > C and disease risk of LC. Decreased expression was detected in 46% (23/50) and increased expression in 54% (27/50) of tumor tissue samples compared to the matched normal tissues of patients. Methylation-related loss of expression was detected in 53.3% (16/30) of patients.

CONCLUSION

Our study is the first investigating four different polymorphic regions of the TNF-α promoter region and the expression/methylation status of TNF-α in the same LC patient and healthy cohort. According to our results, the c.-1031 T > C variant was reported to be significantly associated with a reduced risk of LC. In addition, the TNF-α variant c. -857 C>T suggests that it may be a potential biomarker for predicting the recurrence of LC. An association between c. -857 C>T variant and methylation-based expression status was observed.

A Cancer-Related microRNA Signature Shows Biomarker Utility in Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological malignancy, arising from terminally differentiated B cells, namely plasma cells. miRNAs are small non-coding RNAs that participate in the post-transcriptional regulation of gene expression. In this study, we investigated the role of nine miRNAs in MM. CD138+ plasma cells were selected from bone marrow aspirates from MM and smoldering MM (sMM) patients. Total RNA was extracted and in vitro polyadenylated. Next, first-strand cDNA synthesis was performed using an oligo-dT-adapter primer. For the relative quantification of the investigated miRNAs, an in-house real-time quantitative PCR (qPCR) assay was developed. A functional in silico analysis of the miRNAs was also performed. miR-16-5p and miR-155-5p expression was significantly lower in the CD138+ plasma cells of MM patients than in those of sMM patients. Furthermore, lower levels of miR-15a-5p, miR-16-5p, and miR-222-3p were observed in the CD138+ plasma cells of MM patients with osteolytic bone lesions, compared to those without. miR-125b-5p was also overexpressed in the CD138+ plasma cells of MM patients with bone disease that presented with skeletal-related events (SREs). Furthermore, lower levels of miR-223-3p were associated with significantly worse overall survival in MM patients. In conclusion, we propose a miRNA signature with putative clinical utility in MM.

Modern markers for evaluating bone disease in multiple myeloma (Review)

Multiple myeloma (MM) is a bone marrow neoplasia with increasing incidence compared to previous years. Although new therapeutic molecules have been introduced, it remains an incurable disease with severe repercussions to patients. For many patients, bone disease represents a severe problem often causing pain, pathological bone fractures, and spinal cord compression, which affects the quality of life. This article analyzes the main markers of bone destruction in MM as well as risk factors for severe bone damage. Bone complications have a negative impact on the quality of life of patients with MM, along with other associated complications (renal failure, hypogammaglobulinemia, osteolytic bone disease, hypercalcemia, anemia). The markers of bone destruction described in this article include: interleukin (IL)-6, tumor necrosis factor (TNF)-α, receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), amino- and carboxy-terminal cross-linking telopeptide of type I collagen (NTX, CTX), human bone sialoprotein (BSP) and dickkopf-1 secreted glycoprotein (DKK1). The future practical applicability of this literature review would be the large-scale determination of markers of bone destruction that correlate with the negative evolution to complications of bone disease or the implications that these markers have in regards to treatment.

Dual Role of TNF and LTα in Carcinogenesis as Implicated by Studies in Mice

Tumor necrosis factor (TNF) and lymphotoxin alpha (LTα) are two related cytokines from the TNF superfamily, yet they mediate their functions in soluble and membrane-bound forms via overlapping, as well as distinct, molecular pathways. Their genes are encoded within the major histocompatibility complex class III cluster in close proximity to each other. TNF is involved in host defense, maintenance of lymphoid tissues, regulation of cell death and survival, and antiviral and antibacterial responses. LTα, known for some time as TNFβ, has pleiotropic functions including control of lymphoid tissue development and homeostasis cross talk between lymphocytes and their environment, as well as lymphoid tissue neogenesis with formation of lymphoid follicles outside the lymph nodes. Along with their homeostatic functions, deregulation of these two cytokines may be associated with initiation and progression of chronic inflammation, autoimmunity, and tumorigenesis. In this review, we summarize the current state of knowledge concerning TNF/LTα functions in tumor promotion and suppression, with the focus on the recently uncovered significance of host-microbiota interplay in cancer development that may explain some earlier controversial results.