FOXM1 Promotes Head and Neck Squamous Cell Carcinoma via Activation of the Linc-ROR/LMO4/AKT/PI3K Axis

LincROR promotes tumor growth of colorectal cancer through the miR-145/WNT2B/WNT10A/Wnt/β-catenin regulatory axis

Colorectal cancer (CRC) is a prevalent form of malignant tumor, and the current clinical treatments are far from satisfactory. Identifying new therapeutic targets is therefore essential for clinical practices. The long intergenic non-protein coding RNA lincROR has been shown to play a significant role in the tumorigenesis of various cancers. However, the molecular mechanism underlying lincROR-mediated CRC tumorigenesis remains unclear. In the present study, we found that knockdown of lincROR significantly inhibited cell viability in vitro, while its overexpression promoted tumor growth in vivo. Mechanistically, lincROR acted as a miRNA sponge for miR-145, thereby elevating the expression of the target genes WNT2B and WNT10A. The overexpression of WNT2B and WNT10A definitely activated the Wnt/β-catenin pathway, thus led to promoting tumorigenesis in CRC. In summary, our findings identified lincROR as a novel activator of the Wnt/β-catenin pathway by serving as a miRNA sponge for miR-145 and facilitating tumorigenesis, which suggests that lincROR may be a potential therapeutic target for CRC patients.

Pro-inflammatory cytokine IL-6 regulates LMO4 expression in psoriatic keratinocytes via AKT/STAT3 pathway

The transcription factor LIM-only protein 4 (LMO4) is overexpressed in the psoriatic epidermis and regulates keratinocyte proliferation and differentiation. High LMO4 expression levels are induced by interleukin-23 (IL-23) to activate the AKT/STAT3 signaling pathway. Interleukin-6 (IL-6) is mainly involved in regulating T cell functions and development in patients with psoriasis. However, whether LMO4 expression is regulated by IL-6 remains unclear. Therefore, the purpose of this study is to explore the role and molecular mechanisms of IL-6 in regulating LMO4 expression. The interleukin-6 (IL-6) levels in human plasma were determined using a chemiluminescence immunoassay system. A psoriasis-like mouse model was established using imiquimod induction. Epidermal keratinocytes (HaCaT) were cultured in defined keratinocyte-serum-free medium and stimulated by IL-6 alone or with inhibitors. The proteins of interest were detected using western blot analysis, immunofluorescence, and immunohistochemistry. The 5-ethynyl-2'-deoxyuridine assay was used to detect cell proliferation. The results revealed that IL-6 levels were markedly increased in the plasma of patients with psoriasis, compared to healthy control. The high expression of LMO4 was consistent with high levels of IL-6, p-AKT, and p-STAT3 in the lesions of both psoriasis patients and imiquimod-induced psoriasis-like mice. IL-6 activates the AKT/STAT3 signaling pathway, followed by LMO4 high-expression in HaCaT cells. IL-6 induces HaCaT proliferation and differentiation via AKT/STAT3 signaling pathway activation. We think that the high expression of LMO4 in psoriatic keratinocytes requires IL-6 to activate the AKT/STAT3 signaling pathway and leads to epidermal keratinocytes abnormal proliferation and differentiation.

FOXM1 promotes TGF-β2-induced injury of human lens epithelial cells by up regulating VEGFA expression

OBJECTIVE

To explore whether Fork head box protein M1 (FOXM1) is involved in TGF-β2-induced injury of human lens epithelial cells and its related mechanism.

METHODS

Human lens epithelium samples from cataract patients and healthy controls were collected. A cellular epithelial injury model was established by treating HLE-B3 cells with TGF-β2. QPCR, immunoblot assays were performed to detect the levels of FOXM1 in human cataract samples and the lens epithelial injury cell model. FOXM1 siRNA and pcDNA3.1-FOXM1 plasmids were transfected into the cells to knockdown and overexpress FOXM1, respectively. MTT and wound closure and transwell assays were performed to analyze cell proliferation and migration in HLE-B3 cells. Immunoblot assays were also conducted to detect the effects of FOXM1 on EMT, VEGFA and MAPK/ERK signaling.

RESULTS

We found high expression of FOXM1 in lens tissues of cataract patients. Silencing of FOXM1 in TGF-β2-induced HLE-B3 cells suppressed cell proliferation, migration, and the EMT process. Mechanistically, we found that downregulation of FOXM1 inhibited the VEGFA/MAPK signaling pathway in TGF-β2-induced HLE-B3 cells.

CONCLUSION

FOXM1 promoted TGF-β2-induced injury of human lens epithelial cells (hLECs) by promoting VEGFA expression. FOXM1 could be a potential drug target for the treatment of ocular diseases.

A review on the importance of LINC-ROR in human disorders

Long Intergenic Non-Protein Coding RNA, Regulator Of Reprogramming (LINC-ROR) is a long non-coding RNA with diverse physiological functions. The gene encoding this transcript resides on 18q21.31. Expression levels of LINC-ROR have been reported to be dysregulated in patients with diverse disorders, including cancer, autoimmune disorders and neurodegenerative and neurodevelopmental disorders. Moreover, polymorphisms within this lncRNA have been shown to be associated with a variety of disorders, such as some kinds of cancer and some aspects of systemic lupus erythematous. Abnormal expression of LINC-ROR in some other human disorders is not yet understood. Emerging evidence suggests that LINC-ROR exerts pivotal roles in most types of human disorders as an oncogene. Differentially expressed LINC-ROR contributes in the development of diseases by changing the expression of genes that control the cell cycle. It can also exert its role by affecting the activity of some cancer-related signaling pathways and sponging tumor suppressor miRNAs. Expanding our understanding of LINC-ROR functions will pave the way for developing efficient therapeutic strategies against cancer and related disorders. The current review aims at providing a concise overview of the role of LINC-ROR in diverse human disorders through providing a summary of association studies and expression assays.

Functional Relevance of the Long Intergenic Non-Coding RNA Regulator of Reprogramming (Linc-ROR) in Cancer Proliferation, Metastasis, and Drug Resistance

Cancer is responsible for more than 10 million deaths every year. Metastasis and drug resistance lead to a poor survival rate and are a major therapeutic challenge. Substantial evidence demonstrates that an increasing number of long non-coding RNAs are dysregulated in cancer, including the long intergenic non-coding RNA, regulator of reprogramming (linc-ROR), which mostly exerts its role as an onco-lncRNA acting as a competing endogenous RNA that sequesters micro RNAs. Although the properties of linc-ROR in relation to some cancers have been reviewed in the past, active research appends evidence constantly to a better comprehension of the role of linc-ROR in different stages of cancer. Moreover, the molecular details and some recent papers have been omitted or partially reported, thus the importance of this review aimed to contribute to the up-to-date understanding of linc-ROR and its implication in cancer tumorigenesis, progression, metastasis, and chemoresistance. As the involvement of linc-ROR in cancer is elucidated, an improvement in diagnostic and prognostic tools could promote and advance in targeted and specific therapies in precision oncology.

FOXM1-Mediated Regulation of Reactive Oxygen Species and Radioresistance in Oral Squamous Cell Carcinoma Cells

Radioresistance is a major obstacle to the successful treatment of oral squamous cell carcinoma (OSCC). To help overcome this issue, we have developed clinically relevant radioresistant (CRR) cell lines generated by irradiating parental cells over time, which are useful for OSCC research. In the present study, we conducted gene expression analysis using CRR cells and their parental lines to investigate the regulation of radioresistance in OSCC cells. Based on gene expression changes over time in CRR cells and parental lines subjected to irradiation, forkhead box M1 (FOXM1) was selected for further analysis in terms of its expression in OSCC cell lines, including CRR cell lines and clinical specimens. We suppressed or upregulated the expression of FOXM1 in OSCC cell lines, including CRR cell lines, and examined radiosensitivity, DNA damage, and cell viability under various conditions. The molecular network regulating radiotolerance was also investigated, especially the redox pathway, and the radiosensitizing effect of FOXM1 inhibitors was examined as a potential therapeutic application. We found that FOXM1 was not expressed in normal human keratinocytes but was expressed in several OSCC cell lines. The expression of FOXM1 was upregulated in CRR cells compared with that detected in the parental cell lines. In a xenograft model and clinical specimens, FOXM1 expression was upregulated in cells that survived irradiation. FOXM1-specific small interfering RNA (siRNA) treatment increased radiosensitivity, whereas FOXM1 overexpression decreased radiosensitivity, and DNA damage was altered significantly under both conditions, as well as the levels of redox-related molecules and reactive oxygen species production. Treatment with the FOXM1 inhibitor thiostrepton had a radiosensitizing effect and overcame radiotolerance in CRR cells. According to these results, the FOXM1-mediated regulation of reactive oxygen species could be a novel therapeutic target for the treatment of radioresistant OSCC; thus, treatment strategies targeting this axis might overcome radioresistance in this disease.

FAM64A promotes HNSCC tumorigenesis by mediating transcriptional autoregulation of FOXM1

Head and neck squamous cell carcinoma (HNSCC) still lacks effective targeted treatment. Therefore, exploring novel and robust molecular targets is critical for improving the clinical outcome of HNSCC. Here, we reported that the expression levels of family with sequence similarity 64, member A (FAM64A) were significantly higher in HNSCC tissues and cell lines. In addition, FAM64A overexpression was found to be strongly associated with an unfavorable prognosis of HNSCC. Both in vitro and in vivo evidence showed that FAM64A depletion suppressed the malignant activities of HNSCC cells, and vice versa. Moreover, we found that the FAM64A level was progressively increased from normal to dysplastic to cancerous tissues in a carcinogenic 4-nitroquinoline-1-oxide mouse model. Mechanistically, a physical interaction was found between FAM64A and forkhead box protein M1 (FOXM1) in HNSCC cells. FAM64A promoted HNSCC tumorigenesis not only by enhancing the transcriptional activity of FOXM1, but also, more importantly, by modulating FOXM1 expression via the autoregulation loop. Furthermore, a positive correlation between FAM64A and FOXM1 was found in multiple independent cohorts. Taken together, our findings reveal a previously unknown mechanism behind the activation of FOXM1 in HNSCC, and FAM64A might be a promising molecular therapeutic target for treating HNSCC.