Functional characterization of two variants in the 3'-untranslated region (UTR) of transcription factor 4 gene and their association with schizophrenia in sib-pairs from multiplex families

Association between KRAS gene polymorphisms and genetic susceptibility to breast cancer in a Chinese population

OBJECTIVE

The KRAS gene has a pathophysiological role in the development of many cancers. This study aims to investigate the relationship between KRAS polymorphisms and genetic susceptibility to breast cancer.

METHOD

The rs712, rs12587 and rs9266 gene loci in the KRAS gene of 421 subjects (141 breast cancer patients, 141 benign breast tumours and 139 healthy controls) were analysed by the polymerase chain reaction and SNaPshot sequencing. Transcriptomic information on KRAS and corresponding clinical information was downloaded from the TCGA and GTEx databases. Differences in KRAS expression between breast cancer tissues and control tissues were analysed.

RESULTS

We found no significant association between KRAS rs712 and rs12587 locus gene polymorphisms and an increased risk of developing benign breast tumours and breast cancer (p > 0.05). The KRAS rs9266 locus mutation heterozygous model CT and dominant model CT + TT were significantly associated with an increased risk of breast cancer (both p < 0.05). In addition, the TAT haplotype was expressed at an increased frequency, and the GAC haplotype was expressed at a reduced frequency in breast cancer compared with controls (both p < 0.05). We found that KRAS was over expressed in breast cancer tumour tissues compared with the control tissues (p < 0.0001).

CONCLUSION

The KRAS rs9266 gene polymorphism and the TAT haplotype may be associated with an increased risk of breast cancer in Chinese women. The GAC haplotype may be a protective factor against breast cancer.

Exosomal miR-224-5p from Colorectal Cancer Cells Promotes Malignant Transformation of Human Normal Colon Epithelial Cells by Promoting Cell Proliferation through Downregulation of CMTM4

Background

Interactions between malignant cells and neighboring normal cells are important for carcinogenesis. In addition, cancer cell-derived exosomes have been shown to promote the malignant transformation of recipient cells, but the mechanisms remain unclear.

Methods

The level of miR-224-5p in CRC cell-derived exosomes was determined by RT-qPCR assay. In addition, PKH26 dye-labeled exosomes were used to assess the efficacy of the transfer of exosomes between SW620 and normal colon epithelial cell line CCD 841 CoN.

Results

In this study, we found that overexpression of miR-224-5p significantly promoted the proliferation, migration, and invasion and inhibited the oxidative stress of SW620 cells. In addition, miR-224-5p can be transferred from SW620 cells to CCD 841 CoN cells via exosomes. SW620 cell-derived exosomal miR-224-5p markedly promoted proliferation, migration, and invasion of CCD 841 CoN cells. Meanwhile, SW620 cell-derived exosomal miR-224-5p notably decreased the expression of CMTM4 in CCD 841 CoN cells. Furthermore, SW620 cell-derived exosomal miR-224-5p significantly promoted tumor growth in a xenograft model in vivo.

Conclusion

These findings suggested that SW620 cell-derived exosomal miR-224-5p could promote malignant transformation and tumorigenesis in vitro and in vivo via downregulation of CMTM4, suggesting that miR-224-5p might be a potential target for therapies in CRC.

An actualized screening of schizophrenia-associated genes

Background

Schizophrenia is a psychotic disorder that impacts around 0.5% to 1.2% of the world's population. It has been well established that heredity plays an essential role in the causation of schizophrenia, with genetic heritability of up to 80%. A several new schizophrenia susceptibility genes were identified at the start of the twenty-first century. The aim of this systematic review will be to explore the association between single nucleotide polymorphisms (SNPs) and schizophrenia risk in people all over the world.

Methods

This systematic review collected available data on genetic variants associated with schizophrenia in worldwide populations. A PubMed and Science Direct search was investigated to identify all studies published until December 2020 on genetic susceptibility to schizophrenia in various populations, excluding family studies, transversal studies, cohort studies, experimental studies, and descriptive studies; those that demonstrate an association between repeat polymorphism (CNV, VNTR, etc.). All researches on genetic predispositions of schizophrenia and accepting the predetermined inclusion criteria were included in this systematic review.

Findings

Thirty-six studies focused on the schizophrenia-associated genes were retained in which a total of 44 polymorphisms among 26 susceptibility genes to schizophrenia have been associated in the world populations.

Conclusion

Despite the few number of studies published about genetic of schizophrenia, some genetic variations have been consistently correlated to schizophrenia, particularly in China, as this analysis shows. Further data, especially from genome-wide association studies, might contribute in the development of a reference for schizophrenia genetic susceptibility markers.

Delivery of miR-320a-3p by gold nanoparticles combined with photothermal therapy for directly targeting Sp1 in lung cancer

Lung cancer is the second most common tumor and has the highest mortality rate. Both novel therapeutic targets and approaches are needed to improve the overall survival of patients with lung cancer. MicroRNA-320a-3p belongs to the miR-320a family and has been reported as a tumor suppressor in multiple cancers. However, its definitive role and precise mechanism in the progression of lung cancer remain unclear. In this study, we developed a new type of gold nanorod modified with polyethyleneimine that targets cancer-specific nanoparticles by RGD peptide, which could condense miRNA to self-assemble supramolecular nanoparticles. The designed nanoparticles can achieve integrin αvβ3-targeted cancer therapy, realize photosensitive therapy by laser irradiation and attain gene-targeted therapy by miRNAs. These nanoparticles could deliver miR-320a into lung cancer cells specifically and efficiently. Moreover, we demonstrated that Au-RGD-miR-320a nanoparticles combined with laser irradiation dramatically inhibited the proliferation and metastasis, and enhanced the apoptosis of lung cancer, both in vitro and in vivo. In terms of the mechanism, miR-320a inhibits Sp1 expression by directly binding to the 3'UTR of Sp1, and it eventually enhanced the expression of PTEN and inhibited the expression of matrix metallopeptidase 9 (MMP9). These findings provide a new and promising anticancer strategy via the use of Au-RGD-miR-320a nanoparticles, and identify miR-320a/Sp1 as a potential target for future systemic therapy against lung cancer.