Genetic Variant of DNAM-1 rs763361 C>T Is Associated with Ankylosing Spondylitis in a Mexican Population.

DNAM-1 (CD226) is an activating receptor expressed in CD8+ T cells, NK cells, and monocytes. It has been reported that two SNPs in the DNAM-1 gene, rs763361 C>T and rs727088 G>A, have been associated with different autoimmune diseases; however, the role of DNAM-1 in ankylosing spondylitis has been less studied. For this reason, we focused on the study of these two SNPs in association with ankylosing spondylitis. For this, 34 patients and 70 controls were analyzed using endpoint PCR with allele-specific primers. Our results suggest that rs763361 C>T is involved as a possible protective factor under the CT co-dominant model (OR = 0.34, 95% CI = 0.13-0.88, p = 0.022) and the CT + TT dominant model (OR = 0.39, 95% CI = 0.17-0.90, p = 0.025), while rs727088 G>A did not show an association with the disease in any of the inheritance models. When analyzing the relationships of the haplotypes, we found that the T + A haplotype (OR = 0.31, 95% CI = 0.13-0.73, p = 0.0083) is a protective factor for developing the disease. In conclusion, the CT and CT + TT variants of rs763361 C>T and the T + A haplotype were considered as protective factors for developing ankylosing spondylitis.

Cytotoxic and Antitumoral Effects of Methanolic Extracts of Avocado Fruit Mesocarp in Colorectal Cancer Cell Line HT29.

Colorectal cancer is a widespread neoplasia with high ratios of chemoresistance. Phytochemicals in plant-based extracts could be useful to treat colorectal cancer, and/or reduce chemoresistance. Methanolic extract of avocado mesocarp (MEAM) has demonstrated antitumoral properties, depending on the fruit ripening stage (RS). The aim of this study was to analyze the effects of methanolic extracts of "Hass" avocado fruit at different RS on cytotoxicity, antioxidative, anti-inflammatory, anti-invasive, cell cycle, and epithelial-mesenchymal transition inhibition in colorectal adenocarcinoma cell line HT29. The MEAM showed an increasing concentration of total phenolic compounds as the RS progressed, which was correlated with antioxidant capacity measured by the Ferric Reducing Antioxidant Power assay but not with the 2.2-diphenyl-1-picrylhydrazyl assay. The specific phenolic compounds of MEAM were determined by high-performance liquid chromatography, and it was found that concentrations of epicatechin decreased while concentrations of chlorogenic acid increased as the RS progressed. The HT29 cell line was treated with MEAM for 48 h, and all MEAM had a cytotoxic effect, reported by MTT assay, nevertheless, the strongest effect was associated with the presence of chlorogenic acid. MEAM induced apoptosis and cell cycle arrest in phase G0/G1, reported by flow cytometry. Moreover, MEAM inhibited cell migration evidenced by the wound healing assay. On the other hand, MEAM significantly reduced expression of mRNA of tumor necrosis factor-alpha and cyclooxygenase 2. These effects comprise important inhibition of some hallmarks of cancer. This, in turn, may provide interesting guidelines for developing antitumoral intervention agents.

Non-fitness status of peripheral NK cells defined by decreased NKp30 and perforin, and increased soluble B7H6, in cervical cancer patients.

The NKp30 receptor is one of the three natural cytotoxic receptors reported in NK cells. This receptor is codified by the NCR3 gene, which encodes three isoforms, a consequence of the alternative splicing of exon 4. A greater expression of the three isoforms (A, B, and C), along with low levels of the NKp30 ligand B7H6, has been reported as a positive prognostic factor in different cancer types. Here, in patients with cervical cancer and precursor lesions, we report an altered immune-phenotype, characterized by non-fitness markers, that correlated with increased disease stage, from CIN 1 to FIGO IV. While overall NK cell numbers increased, loss of NKp30+ NK cells, especially in the CD56dim subpopulation, was found. Perforin levels were decreased in these cells. Decreased expression of the NKp30 C isoform and overexpression of soluble B7H6 was found in cervical cancer patients when compared against healthy subjects. PBMCs from healthy subjects downregulated NKp30 isoforms after co-culture with B7H6-expressing tumour cells. Taken together, these findings describe a unique down-modulation or non-fitness status of the immune response in cervical cancer, the understanding of which will be important for the design of novel immunotherapies against this disease.

B7-H6, an immunoligand for the natural killer cell activating receptor NKp30, reveals inhibitory effects on cell proliferation and migration, but not apoptosis, in cervical cancer derived-cell lines.

BACKGROUND: Although great progress has been made in treatment regimens, cervical cancer remains as one of the most common cancer in women worldwide. Studies focusing on molecules that regulate carcinogenesis may provide potential therapeutic strategies for cervical cancer. B7-H6, an activating immunoligand expressed by several tumor cells, is known to activate NK cell-mediated cytotoxicity once engaged with its natural receptor NKp30. However, the opposite, that is, the effects in the tumor cell triggered by B7-H6 after interacting with NKp30 has not yet been well explored. METHODS: In this study, we evaluated the surface expression of B7-H6 by flow cytometry. Later, we stimulated B7-H6 positive cervical cancer derived-cell lines (HeLa and SiHa) with recombinant soluble NKp30 (sNKp30) protein and evaluated biological effects using the impedance RTCA system for cell proliferation, the scratch method for cell migration, and flow cytometry for apoptosis. Cellular localization of B7-H6 was determined using confocal microscopy. RESULTS: Notably, we observed that the addition of sNKp30 to the cervical cancer cell lines decreased tumor cell proliferation and migration rate, but had no effect on apoptosis. We also found that B7-H6 is selectively maintained in tumor cell lines, and that efforts to sort and purify B7-H6 negative or positive cells were futile, as negative cells, when cultured, regained the expression of B7-H6 and B7-H6 positive cells, when sorted and cultivated, lost a percentage of B7-H6 expression. CONCLUSIONS: Our results suggest that B7-H6 has an important, as of yet undescribed, role in the biology of the cervical tumor cells themselves, suggesting that this protein might be a promising target for anti-tumor therapy in the future.

Positive staining of the immunoligand B7-H6 in abnormal/transformed keratinocytes consistently accompanies the progression of cervical cancer.

BACKGROUND: B7-H6 has been revealed as an endogenous immunoligand expressed in a variety of tumors, but not expressed in healthy tissues. Heretofore, no studies have been reported describing B7-H6 in women with cervical cancer. To investigate this question, our present study was conducted. RESULTS: This retrospective study comprised a total of 62 paraffinized cervical biopsies, which were distributed in five groups: low-grade squamous intraepithelial lesions (LSIL), high-grade squamous intraepithelial lesions (HSIL), squamous cervical carcinoma (SCC), uterine cervical adenocarcinoma (UCAC), and a group of cervicitis (as a control for non-abnormal/non-transformed cells). Cervical sections were stained by immunohistochemistry to explore the expression of B7-H6, which was reported according to the immunoreactive score (IRS) system. We observed a complete lack of B7-H6 in LSIL abnormal epithelial cells. Interestingly, B7-H6 began to be seen in HSIL abnormal epithelial cells; more than half of this group had B7-H6 positive cells, with staining characterized by a cytoplasmic and membranous pattern. B7-H6 in the SCC group was also seen in the majority of the sections, showing the same cytoplasmic and membranous pattern. Strong evidence of B7-H6 was notably found in UCAC tumor columnar cells (in 100% of the specimens, also with cytoplasmic and membranous pattern). Moreover, consistent B7-H6 staining was observed in infiltrating plasma cells in all groups. CONCLUSIONS: B7-H6 IRS positively correlated with disease stage in the development of cervical cancer; additionally, B7-H6 scores were found to be even higher in the more aggressive uterine cervical adenocarcinoma, suggesting a possible future therapeutic target for this cancer type.