The role of transcription factors in the crosstalk between cancer-associated fibroblasts and tumor cells

BACKGROUND

Transcription factors (TFs) fulfill a critical role in the formation and maintenance of different cell types during the developmental process as well as disease. It is believed that cancer-associated fibroblasts (CAFs) are activation status of tissue-resident fibroblasts or derived from form other cell types via transdifferentiation or dedifferentiation. Despite a subgroup of CAFs exhibit anti-cancer effects, most of them are reported to exert effects on tumor progression, further indicating their heterogeneous origin.

AIM OF REVIEW

This review aimed to summarize and review the roles of TFs in the reciprocal crosstalk between CAFs and tumor cells, discuss the emerging mechanisms, and their roles in cell-fate decision, cellular reprogramming and advancing our understanding of the gene regulatory networks over the period of cancer initiation and progression.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This manuscript delves into the key contributory factors of TFs that are involved in activating CAFs and maintaining their unique states. Additionally, it explores how TFs play a pivotal and multifaceted role in the reciprocal crosstalk between CAFs and tumor cells. This includes their involvement in processes such as epithelial-mesenchymal transition (EMT), proliferation, invasion, and metastasis, as well as metabolic reprogramming. TFs also have a role in constructing an immunosuppressive microenvironment, inducing resistance to radiation and chemotherapy, facilitating angiogenesis, and even 'educating' CAFs to support the malignancies of tumor cells. Furthermore, this manuscript delves into the current status of TF-targeted therapy and considers the future directions of TFs in conjunction with anti-CAFs therapies to address the challenges in clinical cancer treatment.

CUL4B enhances the malignant phenotype of esophageal squamous cell carcinoma by suppressing TGFBR3 expression

Cullin 4B (CUL4B), which acts as a scaffold protein in CUL4B-RING ubiquitin ligase complexes (CRL4B), is frequently overexpressed in cancer and represses tumor suppressors through epigenetic mechanisms. However, the expression and function of CUL4B in esophageal squamous cell carcinoma (ESCC) have not been well illustrated. In this study, we show that upregulation of CUL4B in ESCC cells enhances proliferation, invasion and cisplatin (CDDP)-resistance, while knockdown of CUL4B significantly represses the malignant activities. Mechanistically, we demonstrate that CUL4B promotes proliferation and migration of ESCC cells through inhibiting expression of transforming growth factor beta receptor III (TGFBR3). CRL4B complex binds to the promoter of TGFBR3, and represses its transcription by catalyzing monoubiquitination at H2AK119 and coordinating with PRC2 and HDAC complexes. Taken together, our findings establish a critical role for the CUL4B/TGFBR3 axis in the regulation of ESCC malignancy.

miRNA-195-5p/PSAT1 feedback loop in human triple-negative breast cancer cells

BACKGROUND

Substantial evidence suggests that non-coding RNAs, such as microRNAs (miRNAs), play a vital role in human cancer. Phosphoserine aminotransferase 1 (PSAT1) is a serine biosynthesis-related member of the aminotransferase family and is closely associated with worse prognosis in triple-negative breast cancer (TNBC).

OBJECTIVE

The present study elucidated the molecular mechanisms underlying PSAT1 regulation by miRNAs in TNBC.

METHODS

After collecting breast cancer and para-cancerous tissues, expression and functional testing of microRNA-195-5p (miR-195-5p) and PSAT1 were implemented both in vivo and in vitro.

RESULTS

Abnormally low miR-195-5p expression was confirmed in TNBC tissues and cells. The specific targeting effect of miR-195-5p on PSAT1 was screened. Our observations revealed that biological tumor behavior was inhibited after miR-195-5p upregulation and this inhibition could be reversed by PSAT1 overexpression both in vivo and in vitro.

CONCLUSION

Our study revealed the regulatory axis of miR-195-5p/PSAT1 in TNBC, suggesting a promising targeted therapy for clinical application.

Vincosamide Has a Function for Inhibiting Malignant Behaviors of Hepatocellular Carcinoma Cells

BACKGROUND

Vincosamide (Vinco) was first identified in the methanolic extract of the leaves of Psychotria leiocarpa, and Vinco has important anti-inflammatory effects and activity against cholinesterase, Vinco also has a trait to anti-tumor. However, whether Vinco can inhibit the malignant behaviors of hepatocellular carcinoma (HCC) cells is still unclear. In the present study, we explored the role of Vinco in suppressing the malignant behaviors of HCC cells.

METHODS

MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide), trypan blue exclusion assay, the Cell Counting Kit (CCK)-8 and flow cytometric analysis were applied to detect the proliferation and apoptosis of HCC cells; electron microscopy was performed to observe the change of cellular mitochondrial morphology; scratch repair and Transwell assays were used to analyze the migration and invasion of HCC cells; expression and localization of proteins were detected by laser confocal microscopy and Western blotting; the growth of the cancer cells in vivo was assessed in a mouse tumorous model.

RESULTS

At a dose of 10 - 80 µg/mL, Vinco inhibited the proliferation, migration, invasion and promoted apoptosis of HCC cells in a dose-dependent manner but had low cytotoxicity effect on normal liver cells. Additionally, 80 µg/mL of Vinco could significantly disrupt the morphology of mitochondria, suppress the migration and invasion of HCC cells. The growth of HCC cells in the animal tumorous model was significantly inhibited after treatment with Vinco (10 mg/kg/day) for 3 days. The results of the present study indicated that Vinco (10 - 80 µg/mL) played a role in activating caspase-3, promoting the expression of phosphate and tension homology deleted on chromosome 10 (PTEN), and inhibiting the phosphorylation of AKT (Ser473) and mTOR (Thr2448); Vinco also has a trait for suppressing the expression of CXCR4, Src, MMP9, EpCAM, Ras, Oct4 and cancer stem cell "stemness markers" CD133 and CD44 in HCC cells.

CONCLUSIONS

Vinco has a role in inhibiting the malignant behaviors of HCC cells; the role molecular mechanism of Vinco may be involved in restraining expression of the growth-, metastasis-related factors, such as Src, Ras, MMP9, EpCAM, CXCR4; activating the activity of caspase-3 and blocking PI3K/AKT signaling pathway. Thus, Vinco should be considered as a new chemotherapy agent for HCC patients.

The role of A-kinase interacting protein 1 in regulating progression and stemness as well as indicating the prognosis in glioblastoma

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AKIP1 was higher in GBM vs. LGG tissues, and in GBM cell lines vs. control cell line.

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AKIP1 promoted GBM cell invasion, CD133+ proportion, and sphere formation ability.

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PI3K/AKT, Notch, EGFR, Ras, ErbB, mTOR pathways linked with AKIP1’s function in GBM.

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AKIP1 correlated with poor prognosis in GBM patients.

Background

A-kinase interacting protein 1 (AKIP1) is recently implicated in the pathogenesis of several solid tumors, while its role in glioblastoma multiforme (GBM) is largely unknown. Therefore, the current study aimed to investigate the effect of AKIP1 on GBM cell malignant behaviors, stemness, and its underlying molecular mechanisms.

Methods

U-87 MG and A172 cells were transfected with control or AKIP1 overexpression plasmid; control or AKIP1 siRNA plasmid. Then cell proliferation, apoptosis, invasion, CD133⁺ cell proportion, and sphere formation assays were performed. Furthermore, RNA-Seq was performed in U-87 MG cells. Besides, AKIP1 expression was detected in 25 GBM and 25 low-grade glioma (LGG) tumor samples.

Results

AKIP1 was increased in several GBM cell lines compared to the control cell line. After transfections, it was found that AKIP1 overexpression increased cell invasion, CD133⁺ cell proportion, and sphere formation ability while less affecting cell proliferation or cell apoptosis in U-87 MG and A172 cells. Moreover, AKIP1 siRNA achieved the opposite effect in these cells, except that it inhibited cell proliferation but induced cell apoptosis to some extent. Subsequent RNA-Seq assay showed several critical carcinogenetic pathways, such as PI3K/AKT, Notch, EGFR tyrosine kinase inhibitor resistance, Ras, ErbB, mTOR pathways, etc. were potentially related to the function of AKIP1 in U-87 MG cells. Clinically, AKIP1 expression was higher in GBM tissues than in LGG tissues, which was also correlated with the poor prognosis of GBM to some degree.

Conclusions

AKIP1 regulates the malignant behaviors and stemness of GBM via regulating multiple carcinogenetic pathways.

LncRNA TUG1 promotes bladder cancer malignant behaviors by regulating the miR-320a/FOXQ1 axis

BACKGROUND

Growing evidence has showed long noncoding RNAs (lncRNAs) play critical roles in bladder cancer (BC) progression. LncRNA taurine upregulated gene 1 (TUG1) was involved in the development of human malignancies. However, the intrinsic and concrete molecular mechanisms of TUG1 in BC remain largely unknown.

METHODS

Expression patterns of TUG1, miR-320a and FOXQ1 in BC tissues and cell lines were measured using qRT-PCR and western blot, respectively. Cell proliferation was detected by CCK-8 and colony formation assays. The capacity of cell migration and invasion was evaluated using wound healing and transwell assay. Tumor xenograft assay was performed to further validate the role of TUG1 in BC progression. Dual luciferase reporter assay and FISH analysis were employed to verify the TUG1/miR-320a/FOXQ1 regulatory network.

RESULTS

TUG1 was significantly higher expression in BC specimens and cell lines. TUG1 knockdown suppressed BC cells malignant behaviors in vitro and inhibited tumor growth and metastasis in vivo, while TUG1 overexpression promoted BC cells malignant behaviors in vitro. However, the function of miR-320a was opposite to that of TUG1, and miR-320a inhibitor partially eliminated the inhibitory effect of TUG1 knockdown on the malignant behavior of BC cells. As a microRNA sponge, TUG1 actively elevated FOXQ1 expression to sponge miR-320a and subsequently promoted BC cells malignant phenotypes.

CONCLUSION

TUG1 may have great potential as therapeutic target for BC, since TUG1 silencing inhibited cell proliferation, migration and invasion in BC, while promoted cell apoptosis, by regulating the miR-320a/FOXQ1 axis.

Long non-coding RNA LINC01116 is activated by EGR1 and facilitates lung adenocarcinoma oncogenicity via targeting miR-744-5p/CDCA4 axis

Background

Lung adenocarcinoma (LAD) is one of the most frequently diagnosed pathological categories of human lung cancer. Nevertheless, the link between long non-coding RNA (lncRNA) LINC01116 and LAD remains poorly investigated.

Methods

QRT-PCR and western blot were applied for quantifying the expression of RNAs and proteins. Both functional experiments assays in vitro and xenografts model in vivo were implemented for analyzing LINC01116 function in LAD while molecular relationship among RNAs was investigated via mechanism experiments.

Results

LINC01116 was expressed at an abnormally high level in LAD, which was induced by transcription activator EGR1. LINC01116 depletion restrained proliferation, migration and invasion, yet facilitated apoptosis of LAD cells. MiR-744-5p could bind to LINC01116. MiR-744-5p inhibitor reversed the inhibitory effects of silencing LINC01116 on LAD malignant behaviors. In addition, cell division cycle-associated protein 4 (CDCA4) shared binding sites with miR-744-5p. Silencing LINC01116 elicited decline in CDCA4 mRNA and protein levels. Moreover, CDCA4 up-regulation could counteract the biological effects of LINC01116 knockdown on LAD cells.

Conclusion

Our data revealed that LINC01116 promoted malignant behaviors of LAD cells by targeting miR-744-5p/CDCA4 axis, implying the theoretical potential of LINC01116 as a novel target for LAD treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01994-w.

circ_0044516 functions in the progression of gastric cancer by modulating MicroRNA-149-5p/HuR axis

Circular RNAs (circRNAs) have emerged as a multifunctional class of RNAs, while there is limited knowledge on their functions in the development of cancers. Herein, we performed the current study to probe into the regulatory mechanism of circ_0044516 in malignant behaviors of gastric cancer (GC) cells with the involvement of microRNA (miR)-149-5p/human antigen R (HuR) axis. Firstly, the expression levels of circ_0044516 in GC cell lines and normal gastric mucosal epithelial cells were determined by qRT-PCR, and GC cell lines with the highest expression of circ_0044516 were screened for further cell experiments. Subsequently, the biological functions of silenced circ_0044516 in GC were identified by CCK-8, colony formation, and transwell assays. Xenograft mouse models were established for in vivo verification. Furthermore, luciferase reporter, RIP, RNA pull-down assay and rescue experiments were performed to explore the sponge regulatory mechanism of circ_0044516. circ_0044516 was suggested to be highly expressed in GC cell lines, and circ_0044516 could promote GC cell proliferation, migration and invasion, as well as in vivo tumor growth. In addition, silenced circ-0044516 reversed the promotive roles in cell viability caused by overexpressed HuR. Furthermore, circ_0044516 mainly localized in the cytoplasm, which may act as a miR-149-5p sponge to modulate HuR expression, thereby playing an essential role in GC development. This study suggests that circ_0044516 may promote HuR expression through sponging miR-149-5p, thereby playing a part in GC progression.

miR-155-5p modulates malignant behaviors of hepatocellular carcinoma by directly targeting CTHRC1 and indirectly regulating GSK-3β-involved Wnt/β-catenin signaling

Background

Hepatocellular carcinoma (HCC) remains one of the most lethal cancers. MicroRNA-155 (miR-155) and collagen triple helix repeat containing 1 (CTHRC1) were found to be involved in hepatocarcinogenesis, but their detailed functions in HCC are unclear. Here, we aimed to investigate the underlying role of miR-155-5p and CTHRC1 in HCC.

Methods

miR-155-5p and CTHRC1 expression levels were detected by qRT-PCR, IHC and WB in HCC patients and cell lines. Dual-luciferase assay, qRT-PCR and WB were used to validate the target interaction between miR-155-5p and CTHRC1. Biological behaviors, including apoptosis, cell cycle progression, and cell proliferation, invasion and migration, were measured by flow cytometry, CCK-8 assay and Transwell tests. A xenograft model was established to examine the effects of miR-155-5p and CTHRC1 on tumor formation. WB was finally utilized to identify the role of GSK-3β-involved Wnt/β-catenin signaling in HCC growth and metastasis.

Results

Our results showed that miR-155-5p and CTHRC1 were down-regulated and up-regulated, respectively, in HCC patients and cell lines. Dual-luciferase assay verified that CTHRC1 was the direct target of miR-155-5p. Moreover, elevated miR-155-5p expression promoted apoptosis but suppressed cell cycle progression and cell proliferation, invasion and migration in vitro and facilitated tumor formation in vivo; elevated CTHRC1 expression abolished these biological effects. Additionally, miR-155-5p overexpression increased metastasis- and anti-apoptosis-related protein expression and decreased pro-apoptosis-related protein expression, while forced CTHRC1 expression conserved the expression of these proteins.

Conclusion

Altogether, our data suggested that miR-155-5p modulated the malignant behaviors of HCC by targeting CTHRC1 and regulating GSK-3β-involved Wnt/β-catenin signaling; thereby, miR-155-5p and CTHRC1 might be promising therapeutic targets for HCC patients.

Silence of Long Noncoding RNA NEAT1 Inhibits Malignant Biological Behaviors and Chemotherapy Resistance in Gastric Cancer

Gastric cancer (GC) is the most common solid tumor in digestive system. Nuclear-enriched abundant transcript 1 (NEAT1) gene is a lncRNA, and reveal potential oncogene role in several malignant tumors. The aim of this study is to investigate the expression and clinical significance of Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) gene and its influence to malignant biologic behaviors and chemotherapy resistance to adriamycin in GC. This study found NEAT1 was up-regulated in GC tissues and cells, especially in in GC adriamycin-resistant cells. NEAT1 silence in SGC7901 cells could inhibit proliferation and invasion ability, and promote cell apoptosis significantly. NEAT1 silence in adriamycin-resistant SGC7901/ADR cells also depressed the half maximal inhibitory concentration (IC50) for adriamycin, chemotherapy resistance to adriamycin was inhibited significantly. NEAT1 knockdown promoted apoptosis in SGC7901/ADR cells induced by adriamycin. In summary, lncRNA NEAT1 is high-expressed in GC and functions as an oncogene to modulate apoptosis, invasion, proliferation and chemotherapy resistance of GC cells, which might be a novel potential therapeutic target for GC.