scholarly journals KLF4 coordinates corneal epithelial apicobasal polarity and plane of cell division, and is downregulated in ocular surface squamous neoplasia

2020 ◽  
Author(s):  
Anil Tiwari ◽  
Sudha Swamynathan ◽  
Vishal Jhanji ◽  
Shivalingappa K. Swamynathan

AbstractApicobasal polarity (ABP) is an important feature of many epithelial cells, including those in the stratified squamous corneal epithelium (CE). Previously, we demonstrated that KLF4 promotes CE homeostasis by suppressing epithelial-mesenchymal transition (EMT) and TGF-β signaling. As dysregulation of TGF-β signaling affects ABP, we investigated the role of KLF4 in regulating cell polarity and plane of division by spatiotemporally regulated ablation of Klf4 in adult ternary transgenic Klf4Δ/ΔCE (Klf4LoxP/LoxP/Krt12rtTA/rtTA/Tet-O-Cre) mouse CE. Klf4Δ/ΔCE cells displayed decreased expression and mis-localization of apical polarity markers Pals1 and Crumbs1, apicolateral Par3, and basolateral Scribble. Cdc42 was upregulated, while Rac and Rho were mis-localized in the Klf4Δ/ΔCE cytoplasm unlike their cortical expression in the control. Phalloidin staining revealed disrupted actin cytoskeleton in the Klf4Δ/ΔCE cells. Survivin and phospho-histone-H3 immunostaining revealed a tilt in the plane of cell division favoring symmetrical divisions with vertical axis in the Klf4Δ/ΔCE compared with predominantly asymmetrical divisions with horizontal axis in the control. Human ocular surface squamous neoplasia (OSSN) tissues displayed signs of EMT and loss of ABP markers PAR3, PALS1 and SCRIB, coupled with downregulation of KLF4. By demonstrating that Klf4 ablation affects CE expression of ABP markers and Rho family GTPases, cytoskeletal actin organization and the plane of cell division, and that KLF4 is downregulated in OSSN tissues that display EMT and lack ABP, these results elucidate the key integrative role of KLF4 in coordinating CE cell polarity and plane of division, loss of which results in OSSN.

2018 ◽  
Vol 8 (1) ◽  
pp. 62 ◽  
Author(s):  
Julianna Maria Santos ◽  
Fazle Hussain

Background: Reduced levels of magnesium can cause several diseases and increase cancer risk. Motivated by magnesium chloride’s (MgCl2) non-toxicity, physiological importance, and beneficial clinical applications, we studied its action mechanism and possible mechanical, molecular, and physiological effects in prostate cancer with different metastatic potentials.Methods: We examined the effects of MgCl2, after 24 and 48 hours, on apoptosis, cell migration, expression of epithelial mesenchymal transition (EMT) markers, and V-H+-ATPase, myosin II (NMII) and the transcription factor NF Kappa B (NFkB) expressions.Results: MgCl2 induces apoptosis, and significantly decreases migration speed in cancer cells with different metastatic potentials.  MgCl2 reduces the expression of V-H+-ATPase and myosin II that facilitates invasion and metastasis, suppresses the expression of vimentin and increases expression of E-cadherin, suggesting a role of MgCl2 in reversing the EMT. MgCl2 also significantly increases the chromatin condensation and decreases NFkB expression.Conclusions: These results suggest a promising preventive and therapeutic role of MgCl2 for prostate cancer. Further studies should explore extending MgCl2 therapy to in vivo studies and other cancer types.Keywords: Magnesium chloride, prostate cancer, migration speed, V-H+-ATPase, and EMT.


2020 ◽  
Vol 20 ◽  
Author(s):  
Qionghui Wu ◽  
Haidong Wei ◽  
Wenbo Meng ◽  
Xiaodong Xie ◽  
Zhenchang Zhang ◽  
...  

: Annexin, a calcium-dependent phospholipid binding protein, can affect tumor cell adhesion, proliferation, apoptosis, invasion and metastasis, as well as tumor neovascularization in different ways. Recent studies have shown that annexin exists not only as an intracellular protein in tumor cells, but also in different ways to be secret outside the cell as a “crosstalk” tool for tumor cells and tumor microenvironment, thus playing an important role in the development of tumors, such as participating in epithelial-mesenchymal transition, regulating immune cell behavior, promoting neovascularization and so on. The mechanism of annexin secretion in the form of extracellular vesicles and its specific role is still unclear. This paper summarizes the main role of annexin secreted into the extracellular space in the form of extracellular vesicles in tumorigenesis and drug resistance and analyzes its possible mechanism.


2020 ◽  
Vol 81 (1) ◽  
Author(s):  
Lina A. Aeshra ◽  
Maiada Moustafa ◽  
Mohammed I. Y. Elmallah ◽  
Said Abdelrahman Salih ◽  
Ibrahim Y. Abdel Kader

Author(s):  
Pedro Carriere ◽  
Natalia Calvo ◽  
María Belén Novoa ◽  
Fernanda Lopez-Moncada ◽  
Alexander Riquelme ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhenming Jiang ◽  
Yuxi Zhang ◽  
Xi Chen ◽  
Pingeng Wu ◽  
Dong Chen

An amendment to this paper has been published and can be accessed via the original article.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiabin Yu ◽  
Li Yang ◽  
Hongting Lu

AbstractMalignant tumors are one of the fatal diseases that threaten children’s physical and mental health and affect their development. Research has shown that the occurrence and development of malignant tumors are associated with the abnormal expression and regulation of genes. Circular RNAs (circRNAs) are noncoding RNAs that have a closed circular structure, with a relatively stable expression, and do not undergo exonuclease-mediated degradation readily. Recent studies have shown that circRNA plays an important role in the occurrence, metastasis, and invasion of solid malignant tumors (SMTs) in children. Thus, circRNA is being considered as a breakthrough in the treatment of SMTs in children. In this review, we describe the functions and mechanisms of circRNAs involved in SMTs in children oncogenesis, and summarize the roles of circRNAs in regulating cell proliferation, cell apoptotic death, the cell cycle, cell migrative and invasive ability, epithelial-mesenchymal transition (EMT), cancer stem cells and drug resistance in SMTs in children. In addition, we also discuss the role of circRNAs in the early diagnosis, pathological grading, targeted therapy, and prognosis evaluation of common SMTs in children. CircRNAs are likely to provide a novel direction in therapy in SMTs of children.


2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Peng Xia ◽  
Hao Zhang ◽  
Kequan Xu ◽  
Xiang Jiang ◽  
Meng Gao ◽  
...  

AbstractHepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. However, there still remains a lack of effective diagnostic and therapeutic targets for this disease. Increasing evidence demonstrates that RNA modifications play an important role in the progression of HCC, but the role of the N7-methylguanosine (m7G) methylation modification in HCC has not been properly evaluated. Thus, the goal of the present study was to investigate the function and mechanism of the m7G methyltransferase WD repeat domain 4 (WDR4) in HCC as well as its clinical relevance and potential value. We first verified the high expression of WDR4 in HCC and observed that upregulated WDR4 expression increased the m7G methylation level in HCC. WDR4 promoted HCC cell proliferation by inducing the G2/M cell cycle transition and inhibiting apoptosis in addition to enhancing metastasis and sorafenib resistance through epithelial-mesenchymal transition (EMT). Furthermore, we observed that c-MYC (MYC) can activate WDR4 transcription and that WDR4 promotes CCNB1 mRNA stability and translation to enhance HCC progression. Mechanistically, we determined that WDR4 enhances CCNB1 translation by promoting the binding of EIF2A to CCNB1 mRNA. Furthermore, CCNB1 was observed to promote PI3K and AKT phosphorylation in HCC and reduce P53 protein expression by promoting P53 ubiquitination. In summary, we elucidated the MYC/WDR4/CCNB1 signalling pathway and its impact on PI3K/AKT and P53. Furthermore, the result showed that the m7G methyltransferase WDR4 is a tumour promoter in the development and progression of HCC and may act as a candidate therapeutic target in HCC treatment.


Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2795
Author(s):  
Sofia Papanikolaou ◽  
Aikaterini Vourda ◽  
Spyros Syggelos ◽  
Kostis Gyftopoulos

Prostate cancer, the second most common malignancy in men, is characterized by high heterogeneity that poses several therapeutic challenges. Epithelial–mesenchymal transition (EMT) is a dynamic, reversible cellular process which is essential in normal embryonic morphogenesis and wound healing. However, the cellular changes that are induced by EMT suggest that it may also play a central role in tumor progression, invasion, metastasis, and resistance to current therapeutic options. These changes include enhanced motility and loss of cell–cell adhesion that form a more aggressive cellular phenotype. Moreover, the reverse process (MET) is a necessary element of the metastatic tumor process. It is highly probable that this cell plasticity reflects a hybrid state between epithelial and mesenchymal status. In this review, we describe the underlying key mechanisms of the EMT-induced phenotype modulation that contribute to prostate tumor aggressiveness and cancer therapy resistance, in an effort to provide a framework of this complex cellular process.


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