Objective:To investigate the expression of long non-coding RNA (lncRNA) ALMS1-IT1 in colorectal cancer tissues and the molecular mechanism of its effect on the proliferation and migration of colorectal cancer HT-29 cells in vitro.Methods:The cancer tissue specimens and paracancerous tissue (>5 cm from the edge of the tumor) specimens were collected from 40 colorectal cancer patients who were diagnosed by pathological examination after surgical resection in Hubei 672 Orthopedic Hospital of Integrated Traditional Chinese and Western Medicine from July 2018 to November 2020. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression level of ALMS1-IT1 in colorectal cancer tissues and paracancerous tissues, when the relative expression of ALMS1-IT1 was higher than or equal to its median relative expression, ALMS1-IT1 was highly expressed, and the correlation of ALMS1-IT1 expression with the clinicopathological characteristics of patients was analyzed. HT-29 cells were infected with the empty lentivirus and the lentivirus carrying the ALMS1-IT1 silence sequence, and named control group and si-ALMS1-IT1 group. qRT-PCR was used to detect the expression of ALMS1-IT1 in the two groups of HT-29 cells. CCK-8 method and Transwell experiment were used to detect the proliferation and migration ability of the two groups of HT-29 cells. The starBase v2.0 online database was used to predict ALMS1-IT1 interacting molecules, and qRT-PCR and Western blot were used to detect the expression of these molecules.Results:The relative expression of ALMS1-IT1 in colorectal cancer tissues was higher than that in paracancerous tissues (4.54±0.61 vs. 1.19±0.31, t = 34.89, P < 0.01). The median relative expression of ALMS1-IT1 in cancer tissues of 40 patients was 2.93, and the high expression rate of ALMS1-IT1 was 50.0% (20/40). The high expression rate of ALMS1-IT1 in cancer tissues of TNM stage Ⅲ patients was higher than that in TNM stage Ⅰ-Ⅱ patients, the high expression rate of ALMS1-IT1 in poorly-differentiated patients was higher than that in well- and moderately-differentiated patients, and the high expression rate of ALMS1-IT1 in patients with lymph node metastasis was higher than that in patients without lymph node metastasis (all P < 0.01). The cell proliferation capacity (absorbance value) of HT-29 cells in the si-ALMS1-IT1 group after cultured for 2, 3, 4, and 5 days was lower than that in the control group (all P < 0.05). The number of cell migration at 24 h in HT-29 cells of the si-ALMS1-IT1 group was less than that of the control group (45±7 vs. 112±18, t = 3.45, P < 0.05). Using starBase v2.0 online database to predict that the target gene of ALMS1-IT1 may be miRNA-889-3p (miR-889-3p), and the target gene of miR-889-3p may be ATAD2. Compared with the control group, the relative expression of miR-889-3p in HT-29 cells of the si-ALMS1-IT1 group increased (4.24±0.46 vs. 1.01±0.11, t = 6.81, P < 0.01). Compared with the control group, ATAD2 mRNA ( P < 0.01) and protein expression levels in the si-ALMS1-IT1 group were reduced. Conclusions:ALMS1-IT1 is highly expressed in colorectal cancer tissues, and the ALMS1-IT1 expression is related to the TNM stage, degree of tumor differentiation and lymph node metastasis of patients. Down-regulation of ALMS1-IT1 in vitro may inhibit the proliferation and migration of colorectal cancer HT-29 cells by regulating the miR-889-3p-ATAD2 axis. ALMS1-IT1 may be a therapeutic target for colorectal cancer.

Objective:To observe the expression of microRNA (miRNA)-7159-5p in gastric cancer tissues, and explore its effect on the proliferation and invasion of gastric cancer cells and its molecular mechanism.Methods:The cancer tissues and adjacent tissues of 29 patients with gastric cancer who underwent surgical resection in Hubei 672 Orthopedic Hospital of Integrated Traditional Chinese and Western Medicine from March 2018 to November 2019 were collected. Fluorescence real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of miR-7159-5p in gastric cancer tissues and adjacent tissues, gastric cancer cell lines and normal gastric epithelial cell lines. Select the cell line with the lowest expression of miR-7159-5p, set the control group and the experimental group, and be transfected with control and miR-7159-5p mimics respectively. qRT-PCR was used to detect the expression of miR-7159-5p in transfected cells. The lymphocyte proliferation test (MTS method) was used to detect the proliferation of transfected cells, and the Transwell chamber method was used to detect the invasion activity of transfected cells. The miRNAMap database and dual luciferase reporter gene experiment were used to predict and verify the target genes of miR-7159-5p. qRT-PCR and Western blot were used to detect the expression of target genes in transfected cells.Results:The expression of miR-7159-5p in gastric cancer tissues was lower than that in adjacent tissues ( P<0.01), the expression of miR-7159-5p in gastric cancer cell lines was lower than that of normal gastric epithelial cells (all P<0.01), and the expression of miR-7159-5p was the lowest in SGC7901 cells ( P<0.01). After transfection, the expression of miR-7159-5p in SGC7901 cells of the experimental group was significantly higher than that in the control group ( P<0.01). After transfection, the proliferation activity and the cell invasion activity of the experimental group was significantly lower than that of the control group (all P<0.01). The target gene of miR-7159-5p was tripartite motif 26 (TRIM26). After transfection, the expression of TRIM26 mRNA in SGC7901 cells of the experimental group was significantly lower than that in the control group ( P<0.01). Western blot showed that after transfection, the expression of TRIM26, c-Myc, cyclin D1, β-catenin protein were lower than those in the control group (all P<0.05). Conclusions:The expression of miR-7159-5p is low in gastric cancer tissues, and miR-7159-5p can inhibit the proliferation and invasion of SGC7901 cells by down-regulating the expression of TRIM26.

The geographical origin of forensic evidence provides important information for crime investigation and solving cases,and is one of the key elements of criminal cases.Previous studies have shown significant differences in the distribution of microorganisms in different regions.Detecting environmental DNA samples and inferring the geographical and spatial sources can provide clues and evidence for case handling.However,due to the diversity of criminal environments and the trace amount of frequently encountered exhibits,stable and reliable technical methods for inferring geographical origin from environmental DNA are not yet available.This article summarizes the sample collection and DNA extraction methods for four types of environmental samples:dust,soil,water,and air.It compares the differences between amplicon sequencing and metagenomic sequencing in studying environmental biological populations,outlines the full process of high-throughput sequencing-based data analysis,and focuses on reviewing the research progress in inferring geographical sources of environmental samples based on bacteria,fungi,and other eukaryotes,to provide references for establishing sequencing and analysis methods for environmental DNA in forensic DNA laboratories and exploring environmental DNA information for forensic applications.