Role of KIR and CD16A genotypes in colorectal carcinoma genetic risk and clinical stage

Impact of HLA Class I Antigen, Killer Inhibitory Receptor, and FCGR3A Genotypes on Breast Cancer Susceptibility and Tumor Stage

BACKGROUND

The identification in breast cancer (BC) of novel genetic biomarkers regulating natural killer (NK) cell function, including the HLA, KIR, and CD16A (FCGR3A), may be still a challenge.

OBJECTIVE

We aimed to evaluate whether the combined effect of these polymorphisms has an impact on BC susceptibility and progression.

METHODS

47 BC Italian patients and healthy individuals (39 females and 66 males/ females) were genotyped by Sanger sequencing (HLA-C exon 2-4 and FCGR3A- 158V/F, 48L/R/H) and PCR-SSP typing (KIR genes).

RESULTS

HLA-C gene allele analysis showed the group C1, with HLA-C*07:02:01 allele, to be significantly associated with tumor progression (16.7% vs. 4.0%, p=0.04, OR=4.867), and instead, group C2, with HLA-C*05:01:01, was protective against disease susceptibility (0.0% vs. 7.2%, p=0.019, OR=0.087). In addition, we highlighted a significant reduction of the KIR2DS4ins in BC patients (pcorr.=0.022) and an increased combined presence of KIR2DL1 and KIR2DS1 genes in advanced BC patients compared to earlier stages (66.7% vs. 19.2%, p=0.002). The concurrent lack of KIR2DL2 and KIR2DS4 genes in the presence of HLA-C2 alleles was significantly associated with increased susceptibility to BC (p=0.012, OR=5.020) or with lymph node involvement (p=0.008, OR=6.375). Lastly, we identified different combinations of the FCGR3A-48/158 variants and KIR genes in BC patients compared to controls.

CONCLUSION

Our findings suggest that in the development of BC probably exists a disorder of the NK innate immunity influenced by KIR/HLA-C gene content and FCGR3A-158 polymorphisms and that the combined analysis of these biomarkers might help predict genetic risk scores for tailored screening of BC patients in therapy.

FCGR3A Is a Prognostic Biomarker and Correlated with Immune Infiltrates in Lower-Grade Glioma

Low-grade gliomas (LGGs) are primary invasive brain tumors that grow slowly but are incurable and eventually develop into high malignant glioma. Fc fragment of IgG receptor IIIa (FCGR3A) gene polymorphism may correlate with some cancers’ treatment responses. However, the expression and prognosis value of FCGR3A and correlation with tumor-immune infiltrate in LGG remain unclear. FCGR3A mRNA expression in gastric cancer (GC) was examined using TIMER and GEPIA databases. Correlations between FCGR3A expression and clinicopathological parameters were analyzed using ULACAN and CGGA databases. GEPIA, OncoLnc, and ULACAN databases were used to examine the clinical prognostic significance of FCGR3A in LGG. TIMER was used to analyze the correlations among FCGR3A and tumor-infiltrating immune cells. Signaling pathways related to FCGR3A expression were identified by LinkedOmics. We found that FCGR3A expression was higher in LGG than in normal tissue and was correlated with various clinical parameters. In addition, high FCGR3A expression predicted poor overall survival in LGG. More importantly, FCGR3A expression positively correlated with immune checkpoint molecules, including PD1, PD-L1, PD-L2, CTLA4, LAG-3 and TIM-3, and tumor-associated macrophage (TAM) gene markers in LGG. GO and KEGG pathway analyses indicated that TUBA1C may potentially regulate the pathogenesis of LGG through immune-related pathways. These findings indicated that FCGR3A plays a vital role in the infiltration of immune cells and could constitute a promising prognostic biomarker in LGG patients.

Aging of the Immune System: Focus on Natural Killer Cells Phenotype and Functions

Aging is the greatest risk factor for nearly all major chronic diseases, including cardiovascular diseases, cancer, Alzheimer’s and other neurodegenerative diseases of aging. Age-related impairment of immune function (immunosenescence) is one important cause of age-related morbidity and mortality, which may extend beyond its role in infectious disease. One aspect of immunosenescence that has received less attention is age-related natural killer (NK) cell dysfunction, characterized by reduced cytokine secretion and decreased target cell cytotoxicity, accompanied by and despite an increase in NK cell numbers with age. Moreover, recent studies have revealed that NK cells are the central actors in the immunosurveillance of senescent cells, whose age-related accumulation is itself a probable contributor to the chronic sterile low-grade inflammation developed with aging (“inflammaging”). NK cell dysfunction is therefore implicated in the increasing burden of infection, malignancy, inflammatory disorders, and senescent cells with age. This review will focus on recent advances and open questions in understanding the interplay between systemic inflammation, senescence burden, and NK cell dysfunction in the context of aging. Understanding the factors driving and enforcing NK cell aging may potentially lead to therapies countering age-related diseases and underlying drivers of the biological aging process itself.

Association of killer cell immunoglobulin-like receptors with endemic Burkitt lymphoma in Kenyan children

Endemic Burkitt lymphoma (eBL) is an aggressive pediatric B cell lymphoma, common in Equatorial Africa. Co-infections with Epstein-Barr virus (EBV) and Plasmodium falciparum, coupled with c-myc translocation are involved in eBL etiology. Infection-induced immune evasion mechanisms to avoid T cell cytotoxicity may increase the role of Natural killer (NK) cells in anti-tumor immunosurveillance. Killer immunoglobulin-like receptor (KIR) genes on NK cells exhibit genotypic and allelic variations and are associated with susceptibility to diseases and malignancies. However, their role in eBL pathogenesis remains undefined. This retrospective study genotyped sixteen KIR genes and compared their frequencies in eBL patients (n = 104) and healthy geographically-matched children (n = 104) using sequence-specific primers polymerase chain reaction (SSP-PCR) technique. The relationship between KIR polymorphisms with EBV loads and eBL pathogenesis was investigated. Possession of ≥ 4 activating KIRs predisposed individuals to eBL (OR = 3.340; 95% CI 1.530-7.825; p = 0.004). High EBV levels were observed in Bx haplogroup (p = 0.016) and AB genotypes (p = 0.042) relative to AA haplogroup and AA genotype respectively, in eBL patients but not in healthy controls. Our results suggest that KIR-mediated NK cell stimulation could mute EBV control, contributing to eBL pathogenesis.

Activating and inhibitory killer cell immunoglobulin like receptors (KIR) genes are involved in an increased susceptibility to colorectal adenocarcinoma and protection against invasion and metastasis

BACKGROUND

A set of activating and inhibitory KIRs (aKIR, iKIR) are involved in NK cell mediated immunity. This study was carried out in order to investigate the KIRs pattern and its association with colorectal carcinoma (CRC) development and clinical outcomes.

METHODS

Sequence-specific primers-polymerase chain reaction (SSP-PCR) for typing of 16 KIR genes was utilized in 165 patients with colorectal adenocarcinoma with 165 age and gender matched healthy controls (CNs).

RESULTS

Possessing KIR2DS1, 2DS5, 3DS1, 2DS4fl, 2DL5, telomeric half KIR genes, ≥ 4 aKIR and CXT4 genotype were associated with an increased susceptibility to colorectal adenocarcinoma while KIR2DS4del and iKIR >aKIR confer resistance to CRC. On the other hand, clinical associations revealed the defensive role of telomeric KIR3DL1, 3DS1, 2DS1, 2DS4, genotypes with ≥ 4 aKIR and more inhibitory KIRs than activating ones (I > A) against metastasis and CXTX genotype in perineural invasion.

CONCLUSION

According to current results it appears that KIRs system play distinctive roles in development and metastasis of colorectal adenocarcinoma.

Human Gut-Associated Natural Killer Cells in Health and Disease

It is well established that natural killer (NK) cells are involved in both innate and adaptive immunity. Indeed, they can recognize molecules induced at the cell surface by stress signals and virus infections. The functions of NK cells in the gut are much more complex. Gut NK cells are not precisely organized in lymphoid aggregates but rather scattered in the epithelium or in the stroma, where they come in contact with a multitude of antigens derived from commensal or pathogenic microorganisms in addition to components of microbiota. Furthermore, NK cells in the bowel interact with several cell types, including epithelial cells, fibroblasts, macrophages, dendritic cells, and T lymphocytes, and contribute to the maintenance of immune homeostasis and development of efficient immune responses. NK cells have a key role in the response to intestinal bacterial infections, primarily through production of IFNγ, which can stimulate recruitment of additional NK cells from peripheral blood leading to amplification of the anti-bacterial immune response. Additionally, NK cells can have a role in the pathogenesis of gut autoimmune inflammatory bowel diseases (IBDs), such as Crohn's Disease and Ulcerative Colitis. These diseases are considered relevant to the generation of gastrointestinal malignancies. Indeed, the role of gut-associated NK cells in the immune response to bowel cancers is known. Thus, in the gut immune system, NK cells play a dual role, participating in both physiological and pathogenic processes. In this review, we will analyze the known functions of NK cells in the gut mucosa both in health and disease, focusing on the cross-talk among bowel microenvironment, epithelial barrier integrity, microbiota, and NK cells.

Redox, immune and genetic biomarker system for personalized treatments in colorectal cancer

BACKGROUND

Identifying biomarkers for the risk of developing degenerative processes linked to aging and colorectal cancer (CRC) onset that could improve clinical strategies.

AIM

To determine valid targets and a predictive biomarker’s system of chronicization of inflammation for cancer treatment.

METHODS

A group of 147 CRC patients was studied. Clinical diagnosis was confirmed histopathologically, and patients were sub-typed using the pathological tumor-node-metastasis classification. Thirteen colon adenoma patients and 219 healthy subjects were also studied. A system biology study on Thioredoxin1/CD30 redox-immune systems (Trx1/CD30), T helper cytokines and polymorphisms of killer immunoglobulin-like receptors, FcγRIIa-131H/R and FcγRIIIa-158V/F was carried out. Enzyme-linked immunosorbent assay was performed to analyze sera. Genetic study was executed by polymerase chain reaction sequence-specific primers and sequence-based typing method. Statistical analysis was performed by using the “Statgraphics software systems”.

RESULTS

We found a positive increase between Trx1/RTrx1 levels and sCD30 level and increased age. With respect to the gender relationships, there were distinct differences. Females showed a primary relationship between transforming growth factor beta (TGFβ) with Trx1, whereas males had one with TGFβ and RTrx1. Trx1/CD30 controls the redox immune homeostasis, and an imbalance in the relationship between the Trx1/RTrx1 and sCD30 levels is linked to the onset and progression of tumor. This event happens through different gender-specific cytokine pathways. Our study demonstrated that the serum levels of Trx1/RTrx1, TGFβ/interleukin (IL)6 and TGFβ/IL4 combinations and the sCD30, IFNγ and IL2 combination constitute a predictive gender specific biomarker system. This is relevant for clinical screening to detect the risk of the potential development or progression of a tumor.

CONCLUSION

Oxidative stress on Trx1/CD30 is a trigger of cancer disease, and the selected oxidation and immune products are a biomarker system for aging and cancer.

The Molecular Mechanism of Natural Killer Cells Function and Its Importance in Cancer Immunotherapy

Natural killer (NK) cells are innate immune cells that show strong cytolytic function against physiologically stressed cells such as tumor cells and virus-infected cells. NK cells show a broad array of tissue distribution and phenotypic variability. NK cells express several activating and inhibitory receptors that recognize the altered expression of proteins on target cells and control the cytolytic function. NK cells have been used in several clinical trials to control tumor growth. However, the results are encouraging only in hematological malignancies but not very promising in solid tumors. Increasing evidence suggests that tumor microenvironment regulate the phenotype and function of NK cells. In this review, we discussed the NK cell phenotypes and its effector function and impact of the tumor microenvironment on effector and cytolytic function of NK cells. We also summarized various NK cell-based immunotherapeutic strategies used in the past and the possibilities to improve the function of NK cell for the better clinical outcome.