Downregulation of short-stature homeobox protein 2 suppresses gastric cancer cell growth and stemness in vitro and in vivo via inactivating wnt/β-catenin signaling.

Gastric cancer (GC) a prevalent form of cancer globally. Previous research suggests that SHOX2 may have a role in promoting cancer progression. However, the role of SHOX2 in GC is not well understood. Based on data from TCGA_GC data set, SHXO2 levels were examined in normal and GC tissues. Patients in the TCGA_GC cohort were divided into high- and low-SHOX2 level groups for analysis of overall survival (OS), functional enrichment, and immune infiltration. Furthermore, experiments were conducted to investigate the impact of SHOX2 on GC cell function through gain- and loss-of-function experiments. Utilizing data from public databases, SHOX2 mRNA levels were found to be elevated in GC tissues compared to normal control, this finding was confirmed by RT-qPCR, western blot analysis, and immune-histochemical analyses. Elevated SHOX2 levels could serve as an independent indicator of poor prognosis in GC patients. Furthermore, SHOX2 levels had a negative correlation with CD8 T cells and CD4 memory activated T cells, and a positive correlation with of M0 macrophages in GC patients. Functional analyses revealed that SHOX2 deficiency notably suppressed GC cell proliferation, migration, and invasion. Additionally, SHOX2 deficiency was shown to suppress stemness in GC cells in vitro and in vivo via inactivating wnt/β-catenin signaling. Collectively, SHOX2 may serve as a prognostic marker for GC patients, and downregulation of SHOX2 could effectively impede GC cell growth and stemness by inactivating the wnt/β-catenin signaling pathway. These findings underscore the potential of SHOX2 as a promising therapeutic target for GC.

Chen X ，Li S ，Sun B 《-》

RHBDD1 Promotes the Growth and Stemness Characteristics of Gastric Cancer Cells by Activating Wnt/β-catenin Signaling Pathway.

Gastric cancer (GC) is threatening public health, with at least one million new cases reported each year. Rhomboid domain-containing protein 1 (RHBDD1) has been identified to regulate the proliferation, migration, and metastasis of cancer cells. However, the role of RHBDD1 in GC has not been elucidated. This study aimed to investigate the role of RHBDD1 on the growth, metastasis, and stemness characteristics of GC. RHBDD1 expression was analyzed from the TCGA databank. qRT-PCR was conducted to evaluate the transcription level of RHBDD1. Western blots were used to evaluate the protein expression of RHBDD1, CD133, CD44, Nanog, β-catenin and c-myc. Colony formation assay and transwell assay were conducted to evaluate the growth and metastasis of NCI-N87 cells, respectively. Sphere-forming assay was performed to study the stemness characteristics. The nude mice xenotransplantation model and immunohistochemistry (IHC) were performed to evaluate the growth of GC in vivo. Results: RHBDD1 expression is elevated in GC cells and clinical tissues. RHBDD1 expression is positively associated with cell proliferation and metastasis of GC cells. RHBDD1 knockdown suppresses the expression of CD133, CD44 and Nanog and attenuates sphere-forming ability. RHBDD1 activates the Wnt/β-catenin pathway via promoting the expression of β-catenin / c-myc and inducing β-catenin translocation into nuclear. RHBDD1 knockdown inhibits the growth of GC in nude mice xenotransplantation model. RHBDD1 is highly expressed in GC, and its knockdown inhibits the growth, metastasis and stemness characteristics of GC cells through activating the Wnt/β-catenin pathway, suggesting that RHBDD1 has the potential to be a novel therapeutic target for GC treatment.

Yang Y ，Yuan Y ，Xia B 《-》

RORβ suppresses the stemness of gastric cancer cells by downregulating the activity of the Wnt signaling pathway.

Wen Z ，Chen M ，Guo W ，Guo K ，Du P ，Fang Y ，Gao M ，Wang Q ... -  《-》

Downregulation of HIGD1B induces mitochondria-mediated apoptosis in gastric cancer cells by inactivating Akt and ERK pathways.

Gastric cancer (GC) is one of the most common malignancies worldwide. Hypoxia-inducible domain (HIGD) family members (e.g., HIGD1A) have been linked to tumor progression. However, the role of HIGD1B (another HIGD family member) in GC has yet to be fully understood. Based on data from TCGA_GC, GSE65801, and GSE65801 data sets, HIGD1B levels were evaluated in normal and GC tissues. Next, HIGD1B levels were validated by reverse transcription-quantitative PCR and western blot analysis analyses. Meanwhile, patients with GC in the TCGA_GC cohort were grouped into high- and low-HIGD1B level groups, and overall survival, functional enrichment, and immune infiltration were analyzed. Additionally, gain- and loss-of-function experiments were performed to determine the function of HIGD1B in GC cells. Compared to normal controls, HIGD1B mRNA levels were significantly elevated in GC tissues. Moreover, high HIGD1B levels may be an independent indicator of poor prognosis in patients with GC. Additionally, high HIGD1B levels were correlated with high stromal and ESTIMATE scores and elevated expression of immune checkpoints in patients with GC. Functional analyses showed that HIGD1B deficiency notably suppressed GC cell proliferation, migration, and invasion. Moreover, HIGD1B deficiency significantly induced mitochondria-mediated apoptosis in GC cells by inactivating Akt and ERK pathways. Collectively, HIGD1B may predict the prognosis of patients with GC and may function as an oncogene in GC. These findings suggest that HIGD1B may serve as a prognostic biomarker and potential therapeutic target in GC.

Chen X ，Sun B ，Li S 《-》

MiR-675 is frequently overexpressed in gastric cancer and enhances cell proliferation and invasion via targeting a potent anti-tumor gene PITX1.

Gastric cancer (GC) is a common malignancy around the world. Irregular expression of microRNAs (miRNAs) contributes to the progression of malignancies. Our study illustrated that miR-675 facilitates GC proliferation and invasion via targeting paired-like homeodomain transcription factor 1 (PITX1) and promoting epithelial-mesenchymal transition (EMT) as well as Wnt/β-catenin signaling pathway. We collected the RNA-seq data of GC and normal stomach tissues from TCGA database to analyze the expression of miR-675 and PITX1. Kaplan-Meier plotter on line tool was used to analyze the association between miR-675 or PITX1 expression and the overall survival of GC patients. The biological function of miR-675 in GC cells was evaluated via altering its expression using miR-675 agomiR or antamiR. Dual-luciferase reporter assay was applied for verifying whether miR-675 could direct bind to 3'UTR of PITX1. Rescue assays were applied for characterizing the effects of miR-675/PITX1 axis on GC growth and invasion. Western blot was performed to evaluate the protein expression levels of PITX1, EMT-related and Wnt signaling-related proteins. Our results showed that miR-675 is up-regulated and predictive of worse prognosis in GC patients. Overexpression of miR-675 in AGS cells notably promoted cell proliferation, migration and invasion, whilst down-regulation of miR-675 in SGC-7901 cells gained the opposite results. PITX1 is down-regulated in GC and identified as a direct target of miR-675. Overexpression of PITX1 in AGS cells reverses cell viability and invasion that enhanced by miR-675 up-regulation. Conversely, depletion of PITX1 in SGC-7901 cells rescues cell viability and invasion that inhibited by miR-675 down-regulation. Western bolt results revealed that miR-675 positively regulated EMT and Wnt/β-catenin signaling pathway in GC cells via targeting PITX1. Our study emphasized the functional mechanism of miR-675 in GC and intimated that miR-675/PITX1 axis possibly affects proliferative and invasive properties of GC cells via regulating EMT and Wnt/β-catenin signaling pathway. Furthermore, miR-675 and PITX1 may be served as early diagnostic markers as well as therapeutic targets for GC.

Liu L ，Tian YC ，Mao G ，Zhang YG ，Han L ... -  《-》