KNTC1 knockdown suppresses cell proliferation of colon cancer

Genome-wide association study on overweight in Brazilian children with asthma: Old stories and new discoveries

INTRODUCTION

Overweight and obesity are chronic and multifactorial diseases with a strong genetic component contributing to weight gain across all age groups. This study aimed to conduct a Genome-wide Association Study (GWAS) on a cohort of 1,004 Brazilian children (5-11 years old) to identify specific DNA regions associated with susceptibility to overweight.

METHODS

The GWAS was performed on children participating in the SCAALA (Asthma and Allergy Social Changes in Latin America) program, with participants classified as either overweight or non-overweight. Genotyping was carried out using the Illumina 2.5 Human Omni bead chip. Using ELISA, cytokine levels (IL-5, IL-13, IL-10, and IFN) were measured in the blood culture supernatant. Furthermore, pathway analyses were conducted utilizing the Gene Ontology tool.

RESULTS

Our analysis revealed eight significant signals distributed across the genome. The most prominent single nucleotide variant (SNV) was identified in the IL1R1 gene, followed by three variants in the LOC105377841 region (located between the ADH5P4 and EYS genes), as well as variants in the KNTC1, RAPTOR, and DSCAM genes. Among the identified variants, three (IL1R1, RAPTOR, and DSCAM) are associated with immune mechanisms, one (ST18) is linked to the death pathway, and one (KNTC1) is associated with mitotic spindle assembly. The genetic risk score analysis demonstrated that having one or more variants among the six analyzed significantly increased the risk of being overweight by eightfold.

CONCLUSIONS

Our study uncovered genetic loci within pathways with strong biological plausibility, including identifying a novel region (LOC105377841) not previously associated with overweight. Understanding the genetic variants involved in overweight and obesity is crucial for advancing our knowledge of these diseases, particularly within mixed populations such as the Brazilian population.

KNTC1 knockdown inhibits the proliferation and migration of osteosarcoma cells by MCM2

Osteosarcoma (OS) is a common primary malignant bone tumor, and it is necessary to further investigate the molecular mechanism of OS progression. The expression of kinetochore associated protein 1 (KNTC1) and minichromosome maintenance 2 (MCM2) was detected by immunohistochemistry, quantitative PCR (qPCR) and Western blot. Gene knockdown or overexpression cell models were constructed and the proliferation, apoptosis, cell cycle and migration were detected in vitro, besides, xenograft models were established to explore the effects of KNTC1 downregulation in vivo. Public databased and bioinformatics analysis were performed to screen the downstream molecules and determine the expression of MCM2 in cancers. KNTC1 was overexpressed in OS tissues and positively correlated with overall survival of OS patients. KNTC1 knockdown inhibited the proliferation and migration, and arrested G2 phase, and induced apoptosis. Besides, KNTC1 downregulation restricted the xenograft tumor formation. MCM2, one of the coexpressed genes, was highly expressed in sarcoma and downregulated after KNTC1 knockdown. MCM2 overexpression heightened the proliferation and migration ability of OS cells, which was reversed the inhibiting effects of KNTC1 knockdown. KNTC1 was overexpressed in OS and promoted the progression of OS by upregulating MCM2.

NK Cell-Monocyte Cross-talk Underlies NK Cell Activation in Severe COVID-19

NK cells in the peripheral blood of severe COVID-19 patients exhibit a unique profile characterized by activation and dysfunction. Previous studies have identified soluble factors, including type I IFN and TGF-β, that underlie this dysregulation. However, the role of cell-cell interactions in modulating NK cell function during COVID-19 remains unclear. To address this question, we combined cell-cell communication analysis on existing single-cell RNA sequencing data with in vitro primary cell coculture experiments to dissect the mechanisms underlying NK cell dysfunction in COVID-19. We found that NK cells are predicted to interact most strongly with monocytes and that this occurs via both soluble factors and direct interactions. To validate these findings, we performed in vitro cocultures in which NK cells from healthy human donors were incubated with monocytes from COVID-19+ or healthy donors. Coculture of healthy NK cells with monocytes from COVID-19 patients recapitulated aspects of the NK cell phenotype observed in severe COVID-19, including decreased expression of NKG2D, increased expression of activation markers, and increased proliferation. When these experiments were performed in a Transwell setting, we found that only CD56bright CD16- NK cells were activated in the presence of severe COVID-19 patient monocytes. O-link analysis of supernatants from Transwell cocultures revealed that cultures containing severe COVID-19 patient monocytes had significantly elevated levels of proinflammatory cytokines and chemokines, as well as TGF-β. Collectively, these results demonstrate that interactions between NK cells and monocytes in the peripheral blood of COVID-19 patients contribute to NK cell activation and dysfunction in severe COVID-19.

Metabolic modulation of mitochondrial mass during CD4+ T cell activation

Mitochondrial biogenesis initiates within hours of T cell receptor (TCR) engagement and is critical for T cell activation, function, and survival; yet, how metabolic programs support mitochondrial biogenesis during TCR signaling is not fully understood. Here, we performed a multiplexed metabolic chemical screen in CD4+ T lymphocytes to identify modulators of metabolism that impact mitochondrial mass during early T cell activation. Treatment of T cells with pyrvinium pamoate early during their activation blocks an increase in mitochondrial mass and results in reduced proliferation, skewed CD4+ T cell differentiation, and reduced cytokine production. Furthermore, administration of pyrvinium pamoate at the time of induction of experimental autoimmune encephalomyelitis, an experimental model of multiple sclerosis in mice, prevented the onset of clinical disease. Thus, modulation of mitochondrial biogenesis may provide a therapeutic strategy for modulating T cell immune responses.

KNTC1 knockdown inhibits proliferation and metastases of liver cancer

To investigate the mechanism of kinetochore-associated protein 1 (KNTC1) in hepatocellular carcinoma. To query the TCGA database for KNTC1 expression in hepatocellular carcinoma. Detection of protein and mRNA levels of KNTC1 in hepatocellular carcinoma cell lines SK-Hep-1, Huh7, HepG2 and SNU449. Cell proliferation, migration and invasion ability were examined after KNTC1 knockdown in SK-Hep-1 and Huh7. Proteins related to KNTC1 were identified through protein interregulation, and their role in hepatocellular carcinoma was investigated. Our results showed that KNTC1 was significantly upregulated in hepatocellular carcinoma tissues and was associated with poorer prognostic survival. The expression of KNTC1 in hepatocellular carcinoma cell lines SK-Hep-1, Huh7, HepG2 and SNU449 was significantly higher than that in normal hepatocyte line L02. Knockdown of KNTC1 in SK-Hep-1 and Huh7 significantly inhibited cell viability, migration ability and invasion ability. KNTC1 is involved in the regulation of hepatocellular carcinoma through its interaction with cyclin-dependent kinase 1 (CDK1). Knockdown of KNTC1 inhibited CDK1 expression, while CDK1 overexpression was able to rescue the regulation of KNTC1 on the viability, migration and invasive ability of hepatocellular carcinoma cell lines. Knockdown of KNTC1 was found to resulted a cell cycle arrest at the S-phase, potentially through the modulation of CDK1, leading to decreased migration and invasion of hepatocellular carcinoma cells. Moreover, knockdown of KNTC1 in mouse transplanted tumors significantly inhibits tumor growth. Inhibition of high expression of KNTC1 in hepatocellular carcinoma was effective in suppressing the progression of hepatocellular carcinoma cells after knockdown. It may be a potential target for the treatment of hepatocellular carcinoma.

KNTC1 and MCM2 are the molecular targets of gallbladder cancer

BACKGROUND

Gallbladder carcinoma is a malignant epithelial tumor of gallbladder with a high degree of malignancy. However, relationship between KNTC1 and MCM2 and gallbladder cancer is unclear.

METHODS

GSE139682 and GSE202479 were downloaded from gene expression omnibus (GEO). Differentially expressed genes (DEGs) were screened. Functional enrichment analysis and gene set enrichment analysis (GSEA) were performed. Protein-protein interaction (PPI) Network was constructed and analyzed. Gene expression heat map was drawn. Comparative toxicogenomics database (CTD) analysis was performed to find diseases most related to core genes. TargetScan was performed for screening miRNAs that regulated central DEGs.

RESULTS

230 DEGs were identified. According to GObp analysis, they were mainly concentrated in regulation of ossification, regulation of spindle microtubule and centromere attachment, cytoskeleton tissue of cortical actin. According to GOcc analysis, they are mainly concentrated in plasma membrane part, cell junction, plasma membrane region and anterior membrane. According to GOmf analysis, they are mainly enriched in protein homodimerization activity, proximal promoter sequence-specific DNA binding and sulfur compound binding. KEGG showed that target genes were mainly enriched in Hippo signal pathway, p53 signal pathway and cancer pathway. KIFC2, TUBG1, RACGAP1, CHMP4C, SFN and MYH11 were identified as core genes. Gene expression heat map showed that KNTC1, MCM2, CKAP2, RACGAP1, CCNB1 were highly expressed in gallbladder carcinoma samples. CTD analysis showed that KNTC1, MCM2, CKAP2, RACGAP1, CCNB1 were associated with head and neck squamous cell carcinoma, necrosis, inflammation and hepatomegaly.

CONCLUSIONS

KNTC1 and MCM2 are highly expressed in gallbladder cancer. Higher expression level correlates with worse prognosis.

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

BACKGROUND

Infertility is a common and rapidly growing health issue around the world. The genetic analysis based on the infertile population is crucial for intervention and treatment.

OBJECTIVE

To find candidate gene locus led to azoospermia in Chinese multi-ethnic groups and provide theoretical guidance for the diagnosis of genetic diseases to progressively aggravated infertility patients and sterile offspring with ART.

METHODS

The study based on whole-exome sequencing (WES) was presented for genetic characteristic analysis of multi-ethnics and identification of variants related to infertility in Xinjiang area of China.

RESULTS

The frequency of pathogenic variants showed significant ethnic differences among four main ethnics in Xinjiang. The population structure analysis confirmed that the Hui was close to the Han population, the Kazak was close to the Uygur population, and there are three ancestry components in the four ethnics. In addition, ten candidate variants potentially regulated azoospermia were detected, and KNTC1 (rs7968222: G > T) was chosen to validate the association. Through the analysis in the valid group, the frequency of rs7968222 (G > T) has a significant difference in the azoospermia population (11.76%, 8/68) and normospermia population (4.63%, 35/756) (P < 0.001). Interestingly, the proportion of people with abnormal follicle-stimulating hormone (FSH) level in the group carrying rs7968222 (G > T) was significantly higher than non-carriers (P < 0.05). Therefore, rs7968222 may regulate spermatogenesis through affecting hormone level.

CONCLUSION

Our study establishes the genetics analysis of Northwest China and finds a candidate gene locus KNTC1 (rs7968222: G > T), which is one of the genetic susceptibility factors for male azoospermia.

Kinetochore-associated protein 1 promotes the invasion and tumorigenicity of cervical cancer cells via matrix metalloproteinase-2 and matrix metalloproteinase-9

Cervical cancer, a common cancer in women, has become a serious social burden. Kinetochore-associated protein 1 (KNTC1) that regulates the cell cycle by regulating mitosis is related to the malignant behavior of different types of tumors. However, its role in the development of cervical cancer remains unclear. In this study, we initially explored the role of KNTC1 in cervical cancer. KNTC1 expression and relevant information were downloaded from The Cancer Genome Atlas (TCGA) and dataset GSE63514 in the Gene Expression Omnibus (GEO) database for bioinformatics analyses. Cell proliferation was detected by cell counting kit-8 (CCK8) and colony formation assays. Wound healing and Transwell assays were used to evaluate cell migration and invasion abilities. Protein expression levels of matrix metallopeptidase 2 (MMP2) and matrix metallopeptidase 9 (MMP9) were measured by western blotting. Nude mouse models of subcutaneous xenograft tumor were constructed to analyze tumor growth in vivo. CCK8 and colony formation assay results demonstrated that the proliferation rate of SiHa and C-33A cells decreased when KNTC1 was silenced. Western blot and Transwell assays indicated that KNTC1 knockdown weakened the invasion and migration abilities of SiHa and C-33A cells and decreased the expression of MMP-2 and MMP-9. In-vivo experiments suggested that the inhibition of KNTC1 reduced tumor growth. Taken together, our study showed that KNTC1 plays an important role in cervical cancer. Further, we verified the promotional effect of KNTC1 on cervical cancer through in-vivo and in-vitro experiments and speculated that KNTC1 might mediate tumor invasion via MMP9 and MMP2.