HMGA1 Regulates the Stem Cell-Like Properties of Circulating Tumor Cells from GIST Patients via Wnt/β-Catenin Pathway

FOSL1 drives the malignant progression of pancreatic cancer cells by regulating cell stemness, metastasis and multidrug efflux system

BACKGROUND

Targeted therapy is an effective strategy for the treatment of advanced and metastatic pancreatic cancer, one of the leading causes for cancer-related death worldwide. To address the limitations of existing targeted drugs, there is an urgently need to find novel targets and therapeutic strategies. Transcription factor FOS like 1 (FOSL1) is a potential therapeutic target for challenging pancreatic cancer, which contributes to the malignant progression and poor gnosis of pancreatic cancer. High mobility group A1 (HMGA1) is a nonhistone chromatin structural protein that contributes to malignant progression and poor prognosis of cancer.

METHODS

Human FOSL1 complete RNA, shRNA against FOSL1 and shRNA against HMGA1 lentiviral recombination vectors were used to overexpress FOSL1 and knock down FOSL1 and HMGA1. RNA sequencing, Q-PCR and Western blots were used to investigate the mechanism of FOSL1 in regulating the proliferation of pancreatic cancer cells. The relationship between FOSL1 and HMGA1 were analyzed by co-immunoprecipitation Mass spectrometry, Q-PCR of chromatin immunoprecipitation and Western blots. The regulation of FOSL1 and HMGA1 in the invasion and migration, stemness, and multidrug efflux system were determined by transwell assay, sphere formation assay, immunofluorescence, Q-PCR and Western blots.

RESULTS

We found that FOSL1 promoted the proliferation and progression of pancreatic cancer by trigging stemness, invasion and metastasis, and drug resistance. HMGA1 was a key downstream target regulated by FOSL1 at the transcriptional level and directly interacted with FOSL1. Knockdown of HMGA1 inhibited the proliferation of pancreatic cancer cells by regulating the expression of genes related to stemness, epithelial-mesenchymal transition and multidrug efflux system. Targeted inhibition of FOSL1 and HMGA1 expression significantly inhibited the proliferation of pancreatic cancer cells.

CONCLUSION

FOSL1 promote the malignant progression of pancreatic cancer by promoting HMGA1 expression. Targeting FOSL1 and HMGA1 in monotherapy or combination therapy is a promising strategy for the treatment of advanced and metastasis pancreatic cancer.

HMGA1 stimulates cancer stem-like features and sensitivity to monensin in gastric cancer

Gastric cancer represents a serious health problem worldwide, with insufficient molecular biomarkers and therapeutic options. Consequently, several efforts have been directed towards finding specific disease markers in order to develop new therapies capable of defeating gastric cancer. Attention has been pointed to cancer stem cells (CSCs) as they are primarily responsible for tumor initiation and recurrence, making them essential therapeutic targets. Using the SORE6-GFP reporter system, based on the expression of SOX2 and/or OCT4 to drive GFP expression, we isolated gastric cancer stem-like cells (SORE6+ cells) enriched in several molecules, including SOX2, C-MYC, KLF4, HIF-1α, NOTCH1 and HMGA1. Here, we explored the previously undisclosed link of HMGA1 with gastric CSCs. Our results indicated that HMGA1 can activate a transcriptional program that includes SOX2, C-MYC, and KLF4 and endows cells with CSC features. We further showed that chemical induction of gastric CSCs using ciclopirox (CPX) can be mediated by HMGA1. Finally, we showed that HMGA1 GFP+ cells were sensitive to monensin confirming the selective activity of this drug over CSCs. Thus, HMGA1 is a key player in the cellular reprogramming of gastric non-CSCs to cancer stem-like cells.

Suspension state affects the stemness of breast cancer cells by regulating the glycogen synthase kinase-3β

Circulating tumor cells (CTCs) are considered an important factor involved in tumor metastasis and can overcome mechanical interactions to gain the ability to distant metastasis. The previous study had shown that the suspension state could regulate the stemness of breast cancer cells (BCCs). However, the specific molecular mechanisms involved have not yet been explored clearly. In this study, MCF-7 and MDA-MBA-231 BCCs were cultured in suspension and adherent. The effect of suspension state on BCCs was further elucidated by observing suspension cell clusters, sorting CD44+/CD24- cell subpopulation and detecting self-renewal ability. Furthermore, it was found that glycogen synthase kinase-3β (GSK-3β) was significantly down-regulated in MCF-7 suspension cells along with the activation of the Wnt/β-catenin signaling, but the converse was true for MDA-MB-231 cells. Subsequently, GSK-3β was differentially expressed in MCF-7 suspension cells. The activation of the Wnt/β-catenin signaling, epithelial-mesenchymal transition (EMT) and stemness were all inhibited when GSK-3 was overexpressed in suspension MCF-7 cells. While GSK-3β was down-regulated, it further promoted the Wnt/β-catenin signaling, mesenchymal characteristic and stemness of MCF-7 cells. This study demonstrated that suspension state could activate the Wnt/β-catenin signaling by inhibiting GSK-3β to promote the stemness of epithelial BCCs, providing a therapeutic strategy for targeted CTCs.

CircPLK1 Acts as a Carcinogenic Driver to Promote the Development of Malignant Pleural Mesothelioma by Governing the miR-1294/HMGA1 Pathway

The deregulation of circular RNAs (circRNAs) is involved in cancer development. CircRNA polo-like kinase 1 (circPLK1) was reported to promote breast cancer development. However, the role of circPLK1 in malignant pleural mesothelioma (MPM) is unclear. The expression of circPLK1, miR-1294, and high mobility group AT-hook 1 (HMGA1) mRNA was measured by quantitative real-time PCR (qPCR). Cell viability was detected by CCK-8 assay. Colony formation ability was monitored by colony formation assay. Cell proliferation was detected by EdU assay. Cell migration and cell invasion were monitored by transwell assay. Cancer cell stemness was investigated by sphere formation assay. The protein levels of marker proteins and HMGA1 expression were measured by western blot analysis. The binding relationship between miR-1294 and circPLK1 or HMGA1 was validated by pull-down assay, dual-luciferase reporter assay or RIP assy. Animal study was performed to disclose the role of circPLK1 in vivo. Exosomes were identified by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). CircPLK1 was upregulated in MPM tumor tissues and cell lines. CircPLK1 knockdown suppressed the proliferation, migration, invasion and stemness of MPM cells. CircPLK1 contained a binding site for miR-1294 and thus bound to miR-1294 to sequester its expression. Inhibition of miR-1294 reversed the effects of circPLK1 knockdown. HMGA1 was a target of miR-1294, and circPLK1 bound to miR-1294 to increase the expression of HMGA1. MiR-1294 restoration also suppressed the proliferation, migration, invasion and stemness of MPM cells, while these effects were abolished by HMGA1 overexpression. In addition, circPLK1 knockdown inhibited tumor growth in vivo. CircPLK1 was overexpressed in exosomes derived from serum of MPM patients. CircPLK1 knockdown inhibited MPM cell proliferation, migration, invasion and stemness by targeting the miR-1294/HMGA1 pathway.

Long Noncoding RNA SNHG22 Induces Cell Migration, Invasion, and Angiogenesis of Gastric Cancer Cells via microRNA-361-3p/HMGA1/Wnt/β-Catenin Axis

Background

The correlation between long non-coding RNAs (lncRNAs) and gastric cancer (GC) has been indicated. As a newly found lncRNA, small nucleolar RNA host gene 22 (SNHG22) functions as an oncogene in ovarian carcinoma and breast cancer. However, its action has not been explored in GC. Herein, the purpose of the current research was to examine the influence of SNHG22 on GC development.

Methods

RT-qPCR was used to identify SNHG22 and microRNA-361-3p (miR-361-3p) in GC tissues and cells. Functional assays were implemented to measure changes on biological activities of GC cells under different transfections. Besides, after human umbilical vein endothelial cells (HUVECs) were co-cultured with supernatant of transfected GC cells, angiogenesis was assessed by tube formation assay in vitro. HMGA1 and β-catenin expression were determined. Finally, mechanistic assays, including RNA pull-down assay and dual-luciferase reporter assay, were employed to assess relationships among SNHG22, miR-361-3p, and HMGA1.

Results

SNHG22 and HMGA1 were highly expressed but miR-361-3p was poorly expressed in GC tissues. Mechanistically, SNHG22 bound to miR-361-3p, and miR-361-3p targeted HMGA1 to disrupt the Wnt/β-catenin pathway. Following SNHG22 or HMGA1 silencing or miR-361-3p upregulation, we observed a decline of proliferation, migration, and invasion of GC cells and HUVEC angiogenesis but acceleration of GC cell apoptosis and cell cycle arrest.

Conclusion

Collectively, SNHG22 silencing possessed tumor-suppressing potentials in GC development via Wnt/β-catenin pathway by binding to miR-361-3p and downregulating HMGA1, highlighting a new promising road for GC treatment development.