Association of MICA-TM and MICB C1_2_A microsatellite polymorphisms with tumor progression in patients with colorectal cancer

Characterization of the genomic alterations in poorly differentiated thyroid cancer

Poorly differentiated thyroid carcinoma (PDTC) is a subtype of thyroid cancer that has a high rate of metastasis or recurrence and a relatively poor prognosis. However, there are few studies that have been conducted on PDTC at the whole protein-coding gene scale. Here, we performed genomic profiling of 15 patients with PDTC originated from follicular thyroid carcinoma using whole exome sequencing and also performed gene functional enrichment analysis of differentially expressed genes (DEGs) for three patients. Further, we investigated genetic variants associated with PDTC progression and the characteristics of clinical pathology. We revealed somatic genomic alterations in the RAF1, MAP2K2, and AKT2 genes that were not reported in previous studies. We confirmed frequent occurrences in the RAS gene in patients with PDTC; the genetic alterations were associated with the RAS-RAF-MEK-ERK/JNK, PI3K-AKT-mTOR signaling pathways, and the cell cycle. DEG analysis showed that immune response was lower in cancer tissues than in normal tissues. Through the association analysis of somatic mutations and the characteristics of clinical pathology from patients with PDTC, the somatic mutations of ABCA12, CLIP1, and ATP13A3 were significantly associated with a vascular invasion phenotype. By providing molecular genetic insight on PDTC, this study may contribute to the discovery of novel therapeutic target candidates.

Major Histocompatibility Complex Class I Chain-Related α (MICA) STR Polymorphisms in COVID-19 Patients

The SARS-CoV-2 disease presents different phenotypes of severity. Comorbidities, age, and being overweight are well established risk factors for severe disease. However, innate immunity plays a key role in the early control of viral infections and may condition the gravity of COVID-19. Natural Killer (NK) cells are part of innate immunity and are important in the control of virus infection by killing infected cells and participating in the development of adaptive immunity. Therefore, we studied the short tandem repeat (STR) transmembrane polymorphisms of the major histocompatibility complex class I chain-related A (MICA), an NKG2D ligand that induces activation of NK cells, among other cells. We compared the alleles and genotypes of MICA in COVID-19 patients versus healthy controls and analyzed their relation to disease severity. Our results indicate that the MICA*A9 allele is related to infection as well as to symptomatic disease but not to severe disease. The MICA*A9 allele may be a risk factor for SARS-CoV-2 infection and symptomatic disease.

MICA ∗012:01 Allele Facilitates the Metastasis of KRAS-Mutant Colorectal Cancer

Major histocompatibility complex (HLA) class I chain-related protein A (MICA) regulates immune surveillance through activation of NKG2D (natural killer group 2D) receptor. However, the genetic association, potential function, and predictive ability of MICA alleles with colorectal cancer (CRC) prognosis remain undefined. In this study, we characterized MICA alleles in tissue samples from 104 patients with CRC and 536 healthy controls and carried out genetic association studies by molecular and clinical CRC phenotypes. Preliminary sequence analysis revealed that MICA ^∗009:01 or ^∗049 alleles were significantly decreased in patients with CRC (p = 0.0049), and further stratification analysis indicated that MICA ^∗012:01 allele was associated with patients with CRC and carrying KRAS codon 12 mutation (p = 0.027). The functional consequences of MICA alleles were examined via transfected CRC cell lines which showed that overexpression of MICA ^∗012:01 enhanced the proliferation, invasion, and metastatic phenotype of CRC. Preliminary analysis of disease-free survival time in patients with and without MICA ^∗012:01 suggest this allele may be predictive for poor prognosis of patients with KRAS codon 12 mutated CRC, as no somatic mutation of MICA gene was detected in CRC tumors compared to paracancerous tissues. Our study indicates that MICA ^∗012:01 allele is associated with KRAS-mutated CRC, facilitates CRC invasion and metastasis, and possibly reduces the survival of patients with KRAS-mutated CRC.

High MICB expression as a biomarker for good prognosis of colorectal cancer

Introduction

Major histocompatibility complex (MHC) plays an important role in colorectal cancer (CRC) immunity. However, the function of MHC class I chain-related B (MICB) molecule is not very clear. In this study, we explored the prognostic effect of MICB in colorectal cancer.

Material and methods

From 2008-05 to 2012-11, consecutive CRC patients of Zhongshan Hospital, Fudan University were retrospectively enrolled as primary cohort. The inclusion criteria were as follows: receiving primary radical resection, pathologically confirmed colorectal adenocarcinoma, no treatment before surgery, clinicopathological data available. Another cohort of CRC patients were collected from a public dataset GSE39582 of GEO database from 1987 to 2007 in the same criteria for validation. MICB was detected using immunochemistry and evaluated as prognostic biomarker. The cut-off value of MICB expression was calculated using X-tile software.

Results

Finally, 863 patients were enrolled in the primary cohort, and 556 patients were enrolled in the validation cohort. MICB expression was significantly associated with tumor size and primary histological type in primary cohort, and with primary tumor location and distant metastases in validation cohort. The survival analysis showed that patients with high MICB expression had significantly better overall survival in both primary (P = 0.002) and validation (P = 0.001) cohorts. The multivariate analysis also confirmed that high MICB expression was a significantly independent protective factor for overall survival in both primary (hazard ratio HR = 0.741, 95% CI 0.594–0.924) and validation (HR = 0.699, 95% CI 0.508–0.961) cohorts.

Conclusion

For stage I–IV CRC patients, MICB was confirmed a novel independent prognostic factor. It could help better stratification of CRC prognosis.

Electronic supplementary material

The online version of this article (10.1007/s00432-020-03159-0) contains supplementary material, which is available to authorized users.

Positive association between MIC gene polymorphism and tuberculosis in Chinese population

The disease progression and morbidity of tuberculosis (TB) infections are determined by virulence of the micro-organism, host genetic factors and environmental factors. The highly polymorphic MHC class I chain-related gene (MIC) could serve as a potential host genetic candidate. To investigate the association of MIC polymorphism with TB infection, 124 patients and 191 ethnically matched controls from Hunan province, Southern China, were genotyped for the MIC polymorphism using polymerase chain reaction-sequence specific priming and sequencing-based typing. The results showed that allele frequencies of MIC-sequence and MICA-STR were different in TB patients in comparison to normal controls (both P < 0.05). MICA-A4 and MICA*012:01 alleles were positive associated (OR = 2.42, 95% CI: 1.69-3.87; OR = 3.41, 95% CI: 2.19-5.33, respectively, both P_c < 0.05) while MICA -A5 were inversely associated (OR = 0.59, 95%CI: 0.41-0.94, P_c < 0.05) with TB. Homozygote MICA*012:01/012:01 was observed to have significant risk effects on TB (OR = 4.76, 95% CI: 1.94-11.69, P_c0000-0001-5151-1853 < 0.05). Additionally, MICB*008 allele conduct a significant risk effect for TB (OR = 3.17, 95%CI: 1.80-5.61, P_c < 0.05). All the data showed that MIC polymorphism was associated with the variable susceptibility to TB in Chinese population.

Association between MICA polymorphisms, s-MICA levels, and pancreatic cancer risk in a population-based case-control study

BACKGROUND

Pancreatic tumor cells may avoid immune surveillance by releasing the transmembrane major histocompatibility complex class I chain-related A (MICA) protein in soluble form (s-MICA). We hypothesized that the presence of the A5.1 polymorphism in the MICA gene, which encodes a truncated MICA protein, is associated with higher s-MICA levels and increased pancreatic cancer risk.

METHODS

MICA alleles and s-MICA levels were measured in 121 pancreatic cancer cases and 419 controls. General linear regression with a log transformation assessed geometric means of s-MICA levels across MICA alleles. Unconditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI) for pancreatic cancer associated with MICA alleles.

RESULTS

After multivariate adjustment, participants with at least one copy of the A5.1 allele versus no A5.1 allele had 1.35 (95% CI: 1.05-1.74) times greater s-MICA levels (1.65 times higher for cases and 1.28, for controls) and increased risk of pancreatic cancer (OR = 1.91, 95% CI: 1.05-3.48).

CONCLUSIONS

Our study suggests higher risk of pancreatic cancer among those with the MICA A5.1 polymorphism, which may be explained by an increase in s-MICA secretion and impaired immune response.

IMPACT

These findings provide further evidence at the genetic and molecular level of the important role of MICA in pancreatic cancer development, and may have important implications with regards to pancreatic cancer screening.

Single nucleotide polymorphism of rs2596542 and the risk of hepatocellular carcinoma development: A meta-analysis

BACKGROUND

Major histocompatibility complex class I-related chain A (MICA) is considered as a tumor antigen, and its expression is affected by its genetic polymorphisms. However, the relationship between rs2596542 polymorphisms in MICA promoter region and hepatocellular carcinoma (HCC) is not fully elucidated so far. This study aims to explore the relationship between single nucleotide polymorphism of rs2596542 and the risk of HCC development through meta-analysis.

METHODS

MEDLINE, Web of Science, and EMBASE databases were systematically searched to identify relevant studies. A meta-analysis was performed to examine the association between MICA rs2596542 polymorphism and susceptibility to HCC. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Fourteen case-control studies involving 4,900 HCC cases and 19,519 controls were included. The MICA rs2596542C allele was significantly associated with decreased risk of HCC based on allelic contrast (OR = 0.76, 95% CI = 0.69-0.83, P < .001), homozygote comparison (OR = 0.57, 95% CI = 0.48-0.69, P < .001), and a recessive genetic model (OR = 0.77, 95% CI = 0.65-0.91, P < .001), whereas patients carrying the MICA rs2596542TT genotype had significantly higher risk of HCC than those with the CT or CC genotype (TT vs CT + CC, OR = 1.57, 95% CI = 1.36-1.81, P < .001). Subgroups analyses based on the ethnic or the source of control groups found very similar findings.

CONCLUSION

The C allele in MICA rs2596542 is a protective factor for hepatocarcinogenesis, whereas the T allele is a risk factor. Further large and well-designed studies are needed to confirm this conclusion.

The association between MICA/MICB polymorphism and respiratory syncytial virus infection in children

MICA/MICB gene polymorphisms are related to several cancers and infectious diseases, but there are no reports on the association between MICA/MICB gene polymorphisms and respiratory syncytial virus (RSV) infection. To clarify the association between MICA/MICB gene polymorphisms and infection of RSV in children, we collected fresh blood samples from paediatric patients with and without pneumonia after RSV infection. The MICA/MICB alleles were characterized by PCR sequence-specific primers (PCR-SSP) and PCR sequence-based genotyping (PCR-SBT), and then, the frequency of the MICA/MICB alleles and haplotypes was calculated. The results showed that the frequencies of MICA*002:01 and MICA-A9 in RSV-infected patients were significantly lower than in controls (9% vs. 20%, pc = 0.04). The allele frequency of MICA*002:01 in pneumonia patients (8%) and nonpneumonia patients (9%) was significantly lower than in controls (20%, pc = 0.02). MICA*002:01-MICB*008(Δrel = 0.616), MICA*009-MICB*016 (Δrel = 0.506), and MICA*045-MICB*014 (Δrel = 0.700) showed linkage disequilibrium in patients infected with RSV. The haplotype frequency of MICA*002:01-MICB*005:02 in RSV-infected patients was significantly lower than in controls (10% vs. 16%, pc = 0.033). In conclusion, allele MICA*002:01/A9 and haplotype MICA*002:01-MICB*005:02 were negatively associated with RSV respiratory tract infections.

MICA*A4 protects against ulcerative colitis, whereas MICA*A5.1 is associated with abscess formation and age of onset

Ulcerative colitis (UC) is one of the two major forms of inflammatory bowel disease, the aetiology of which remains unknown. Several studies have demonstrated the genetic basis of disease, identifying more than 130 susceptibility loci. The major histocompatibility complex class I chain-related gene A (MICA) is a useful candidate to be involved in UC pathogenesis, because it could be important in recognizing the integrity of the epithelial cell and its response to stress. The aim of this study was to analyse the relationship between polymorphisms in the transmembrane domain of MICA and susceptibility to develop UC. A total of 340 patients with UC and 636 healthy controls were genotyped for MICA transmembrane polymorphism using a polymerase chain reaction (PCR) combined with fluorescent technology. Different MICA alleles were determined depending on the PCR product size. The allele MICA*A4 was less frequent in patients than in controls (P = 0·003; OR = 0·643), and this protective role is higher when it forms haplotype with B*27 (P = 0·002; OR = 0·294). The haplotype HLA-B*52/MICA*A6 was also associated with UC [P = 0·001; odds ratio (OR) = 2·914]. No other alleles, genotypes or haplotypes were related with UC risk. Moreover, MICA*A5.1 is associated independently with abscesses (P = 0·002; OR = 3·096) and its frequency is lower in patients diagnosed between ages 17 and 40 years (P = 0·007; OR = 0·633), meaning an extreme age on onset. No association with location, extra-intestinal manifestations or need for surgery was found.

MICA polymorphisms and cancer risk: a meta-analysis

The major histocompatibility complex class I chain-related gene A transmembrane (MICA-TM) polymorphism has been implicated in susceptibility to cancer. However, the results are inconsistent. The aim of this meta-analysis is to evaluate the association between the MICA-TM polymorphisms and cancer risk. All eligible case-control studies published up to August 20, 2014 were identified by searching PubMed, Web of Science, CNKI and Wanfang databases. The cancer risk associated with the MICA polymorphism was estimated for each study by odds ratios (OR) together with its 95% confidence interval (CI), respectively. 21 studies from 19 publications with 3620 cases and 4903 controls were included. Overall, no significant associations between the MICA-TM polymorphism and cancer risk were found (A4 allele: OR = 0.97, 95% CI: 0.88-1.07; A5 allele: OR = 0.91, 95% CI: 0.81-1.04; A5.1 allele: OR = 1.03, 95% CI: 0.89-1.18; A6 allele: OR = 1.05, 95% CI: 0.95-1.15; A9 allele: OR = 0.96, 95% CI: 0.80-1.14; A10 allele: OR = 0.88, 95% CI: 0.43-1.79; del: OR = 2.50, 95% CI: 0.73-8.58; A7 allele: OR = 0.93, 95% CI: 0.43-2.00). When stratified by ethnicity, similar results were observed among Asians; however, there were significant association in Caucasian population for A5 (OR = 0.77, 95% CI: 0.68-0.87) and A9 allele (OR = 0.75, 95% CI: 0.66-0.85). This meta-analysis suggests that the MICA-TM A5 and A9 alleles may be an important protective factor for cancer in Caucasian populations.

MICA polymorphism: biology and importance in cancer

The major histocompatibility complex class I polypeptide-related sequence A gene (MICA) encodes a membrane-bound protein acting as a ligand to stimulate an activating receptor, NKG2D, expressed on the surface of essentially all human natural killer (NK), γδ T and CD8(+) αβ T cells. MICA protein is absent from most cells but can be induced by infections and oncogenic transformation and is frequently expressed in epithelial tumors. Upon binding to MICA, NKG2D activates cytolytic responses of NK and γδ T cells against infected and tumor cells expressing MICA. Therefore, membrane-bound MICA acts as a signal during the early immune response against infection or spontaneously arising tumors. On the other hand, human tumor cells spontaneously release a soluble form of MICA, causing the downregulation of NKG2D and in turn severe impairment of the antitumor immune response of NK and CD8(+) T cells. This is considered to promote tumor immune evasion and also to compromise host resistance to infections. MICA is the most polymorphic non-classical class I gene. A possible association of MICA polymorphism with genetic predisposition to different cancer types has been investigated in candidate gene-based studies. Two genome-wide association studies have identified loci in MICA that influence susceptibility to cervical neoplasia and hepatitis C virus-induced hepatocellular carcinoma, respectively. Given the current level of interest in the field of MICA gene, we discuss the genetics and biology of the MICA gene and the role of its polymorphism in cancer. Gaps in our understanding and future research needs are also discussed.

Microarrays for high-throughput genotyping of MICA alleles using allele-specific primer extension

The role of major histocompatibility complex (MHC) class I chain-related gene A (MICA), a ligand of NKG2D, has been defined in human diseases by its allele associations with various autoimmune diseases, hematopoietic stem cell transplantation (HSCT) and cancer. This study describes a practical system to develop MICA genotyping by allele-specific primer extension (ASPE) on microarrays. From the results of 20 control primers, strict and reliable cut-off values of more than 30,000 mean fluorescence intensity (MFI) as positive and less than 3000 MFI as negative, were applied to select high-quality specific extension primers. Among 55 allele-specific primers, 44 primers could be initially selected as optimal primer. Through adjusting the length, six primers were improved. The other failed five primers were corrected by refractory modification. MICA genotypes by ASPE on microarrays showed the same results as those by nucleotide sequencing. On the basis of these results, ASPE on microarrays may provide high-throughput genotyping for MICA alleles for population studies, disease-gene associations and HSCT.

Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region

Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.

Possible association of decreased NKG2D expression levels and suppression of the activity of natural killer cells in patients with colorectal cancer

Natural-killer group 2 (NKG2), a natural killer (NK) cell receptor, plays a critical role in regulating NK cytotoxicity. In this study, we investigated the expression levels of natural killer group 2 member A (NKG2A) and natural killer group 2 member D (NKG2D) in NK cells as well as the regulatory function of NKG2D in patients with colorectal cancer (CRC). Sixty-two CRC patients and 32 healthy controls were enrolled in this study. The expression levels of NKG2A and NKG2D mRNA in peripheral blood mononuclear cells (PBMCs) were investigated using real-time PCR. Flow cytometry was performed to assay the levels of NKG2A and NKG2D proteins in NK cells. The levels of NKG2D mRNA in PBMCs in the patients were significantly lower than those in the controls [mean ± SD, 1.11±0.60 (CRC patients) vs. 1.65±0.71 (healthy controls); p<0.01], whereas the 2 groups showed no apparent difference in the levels of NKG2A mRNA (p>0.05). In addition, the patients showed significantly lower NKG2D levels in NK cells than the controls did (71.23%±8.31% [CRC patients] vs. 79.39%±5.58% [healthy controls]; p<0.01). However, we observed no distinct difference in the NKG2A expression levels in NK cells between the 2 groups (p>0.05). Notably, blockage of NKG2D signaling with anti-NKG2D antibodies ex vivo resulted in decreased cytotoxicity and CD107a degranulation. Our data revealed that the decrease in NKG2D expression levels may have been associated with suppression of NK cell activity in CRC patients.

Major histocompatibility complex class I chain-related gene polymorphisms: associated with susceptibility to Kawasaki disease and coronary artery aneurysms

BACKGROUND

Kawasaki disease (KD) involves a complex interaction of immunoinflammatory process, cytokine activation, and genetic factors. We aimed to investigate whether genetic variations in a major histocompatibility complex (MHC) class could be used as markers of susceptibility in KD and coronary artery aneurysm lesions (CALs).

METHODS

Individuals were divided into following groups: (1) normal controls; (2) KD with CAL; (3) KD without CAL. Polymorphisms for MHC class I chain-related genes A (MICA) (rs2301747, rs2256184, rs2848716), MICB (rs2855804, rs3132464, rs2516400), BAT3 (rs750332), MSH5 (rs1150793), and chromosome 6 open reading frame 27 (C6orf27, rs707928) were genotyped with polymerase chain reaction and the TaqMan(®) allelic discrimination assay. Genotypes, alleles, and haplotype in each group were compared.

RESULTS

Genotype and allele frequency of MICB*rs2516400 polymorphisms in each group were significantly different. MICB (rs2516400)*C-related genotypes/alleles are correlated with development of KD and CAL. Proportions of rs2516400*TT/TC/CC were (1) 1/39/60%, (2) 0/0/100%, and (3) 0/0/100%. Other single-nucleotide polymorphisms were not associated with KD susceptibilities. Haplotypes (rs2301747-rs2256184-rs2848716-rs2855804-rs3132464-rs2516400-rs750332-rs1150793-rs707928) G-G-G-C-T-C-T-A-A, C-A-G-T-T-C-T-A-A, and G-G-G-C-C-C-T-A-A were associated with higher susceptibilities for KD. The G-G-G-T-T-T-T-G-G and C-G-G-T-T-T-T-A-A haplotypes were associated with lower susceptibilities.

CONCLUSION

MICB*rs2516400 polymorphisms and some MHC class I-related haplotypes are associated with KD susceptibility. MICB and MHC class I genetic variations might contribute to the pathogenesis of KD and CAL.