Transcriptional regulation of FoxM1 by HIF‑1α mediates hypoxia‑induced EMT in prostate cancer

Newborn apical resection preserves the proliferative capacity of cardiomyocytes located throughout the left ventricle

BACKGROUND

When pigs underwent apical resection (AR) on postnatal day (P) 1 (ARP1) followed by myocardial infarction (MI) on P28, the hearts had little evidence of scarring; meanwhile, hearts underwent MI on P28 without ARP1 showed large infarcts on P56; and the improvement of ARP1 hearts was driven primarily by cardiomyocyte proliferation. AR and MI were performed ~5 mm (AR) and ~20 mm (MI) above the heart apex; thus, we hypothesize that ARP1 preserved the cardiomyocytes cell-cycle throughout the left ventricle, rather than only near the resection site.

METHODS

Sections of cardiac tissue were collected from the left ventricle of uninjured pigs and from both the border zone (BZ) of AR and uninjured regions (remote zone, [RZ]) in ARP1 hearts. Cardiomyocyte proliferation was evaluated via immunofluorescence analysis of phosphorylated histone 3 [PH3] and symmetric Aurora B (sAuB). Single nucleus RNA sequencing (snRNAseq) data collected from the hearts of fetal pigs, uninjured pigs, and the BZ and RZ of ARP1 pigs was evaluated via our cell-cycle-specific autoencoder to identify proliferating cardiomyocytes.

RESULTS

Cardiomyocyte PH3 and sAuB expression, and percentage of proliferating cardiomyocytes in snRNA data was significantly more common in both BZ and RZ of ARP1 than uninjured hearts but did not differ significantly between the ARP1-BZ and ARP1-RZ at any time point. Heat shock proteins HSPA5 and HSP90B1 were overexpressed at both ARP1-BZ and ARP1-RZ. In AC16 cell, overexpression (and knockdown) of HSPA5-HSP90B1 increased (and decrease) cell-cycle activity.

CONCLUSION

ARP1 preserved proliferative capacity of cardiomyocytes located throughout the left ventricle.

TRPM channels in human cancers: regulatory mechanism and therapeutic prospects

The transient receptor potential melastatin (TRPM) channel family has been previously implicated in various diseases, including those related to temperature sensing, cardiovascular health, and neurodegeneration. Nowadays, increasing evidence indicates that TRPM family members also play significant roles in various types of cancers, exhibiting both pro- and anti-tumorigenic functions. They are involved in tumor cell proliferation, survival, invasion, and metastasis, serving as potential diagnostic and prognostic biomarkers for cancer. This paper begins by describing the structure and physiological functions of the TRPM family members. It then outlines their roles in several common malignancies, including pancreatic, prostate, colorectal, breast, brain cancer, and melanoma. Subsequently, we focused on investigating the specific mechanisms by which TRPM family members are involved in tumorigenesis and development from both the tumor microenvironment (TME) and intracellular signaling. TRPM channels not only transmit signals from the TME to regulate tumor cell functions, but also mediate extracellular matrix remodeling, which is conducive to the malignant transformation of tumor cells. Importantly, TRPM channels depend on the regulation of the inflow of various ions in cells, and participate in key signaling pathways involved in tumor progression, such as Wnt/β-catenin, MAPK, PI3K/AKT, p53, and autophagy. Finally, we summarize the current strategies and challenges of targeting TRPM channels in tumor treatment, and discuss the feasibility of combining targeted TRPM channel drugs with cancer immunotherapy.

Impact of Hypoxia and the Levels of Transcription Factor HIF-1α and JMJD1A on Epithelial-Mesenchymal Transition in Head and Neck Squamous Cell Carcinoma Cell Lines

BACKGROUND/AIM

This study aimed to assess the impact of hypoxia on epithelial-mesenchymal transition (EMT) in head and neck squamous cell carcinoma (HNSCC), focusing on the involvement of transcription factors hypoxia inducible factor 1 (HIF-1α) and Jumonji Domain-Containing Protein 1A (JMJD1A).

MATERIALS AND METHODS

FaDu and Cal33 cell lines were subjected to hypoxic and normoxic conditions. Cell proliferation was quantified electronically, while PCR and western blot analyses were used to measure mRNA and protein levels of HIF-1α, JMJD1A, and EMT markers. EMT was further characterized through immunofluorescence, migration, and invasion assays.

RESULTS

Hypoxic conditions significantly reduced cell proliferation after 48 hours in both cell lines. HIF-1α mRNA levels increased initially during short-term hypoxia but declined thereafter, while JMJD1A mRNA levels showed a sustained increase with prolonged hypoxia. Western blot analysis revealed contrasting trends in protein levels. EMT marker expression varied markedly over time at both the mRNA and protein levels, suggesting EMT induction in hypoxia within 24 hours. Immunofluorescence, migration, and invasion assays supported these findings.

CONCLUSION

The study provides evidence of hypoxia-induced EMT in HNSCC, although conflicting results suggest a complex interplay among molecular regulators involved in this process.

Epithelial-mesenchymal transition in an EcPV2-positive vulvar squamous cell carcinoma of a mare

BACKGROUND

Vulvar squamous cell carcinoma (VSCC) has been recently associated with Equus caballus papillomavirus type 2 (EcPV2) infection. Still, few reports concerning this disease are present in the literature.

OBJECTIVE

To describe a case of naturally occurring EcPV2-induced VSCC, by investigating tumour ability in undergoing the epithelial-to-mesenchymal transition (EMT).

STUDY DESIGN

Case report.

METHODS

A 13-year-old Haflinger mare was referred for a rapidly growing vulvar mass. After surgical excision, the mass was submitted to histopathology and molecular analysis. Histopathological diagnosis was consistent with a VSCC. Real-time qPCR, real-time reverse transcriptase (RT)-qPCR and RNAscope were carried out to detect EcPV2 infection and to evaluate E6/E7 oncogenes expression. To highlight the EMT, immunohistochemistry (IHC) was performed. Expression of EMT-related and innate immunity-related genes was investigated through RT-qPCR.

RESULTS

Real-time qPCR, RT-qPCR and RNAscope confirmed EcPV2 DNA presence and expression of EcPV2 oncoproteins (E6 and E7) within the neoplastic vulvar lesion. IHC highlighted a cadherin switch together with the expression of the EMT-related transcription factor HIF1α. With RT-qPCR, significantly increased gene expression of EBI3 (45.0 ± 1.62, p < 0.01), CDH2 (2445.3 ± 0.39, p < 0.001), CXCL8 (288.7 ± 0.40, p < 0.001) and decreased gene expression of CDH1 (0.3 ± 0.57, p < 0.05), IL12A (0.04 ± 1.06, p < 0.01) and IL17 (0.2 ± 0.64, p < 0.05) were detected.

MAIN LIMITATIONS

Lack of ability to generalise and danger of over-interpretation.

CONCLUSION

The results obtained were suggestive of an EMT event occurring within the neoplastic lesion.

Integrating spatial transcriptomics and single-cell RNA-sequencing reveals the alterations in epithelial cells during nodular formation in benign prostatic hyperplasia

OBJECTIVE

Proliferative nodular formation represents a characteristic pathological feature of benign prostatic hyperplasia (BPH) and serves as the primary cause for prostate volume enlargement and consequent lower urinary tract symptoms (LUTS). Its specific mechanism is largely unknown, although several cellular processes have been reported to be involved in BPH initiation and development and highlighted the crucial role of epithelial cells in proliferative nodular formation. However, the technological limitations hinder the in vivo investigation of BPH patients.

METHODS

The robust cell type decomposition (RCTD) method was employed to integrate spatial transcriptomics and single cell RNA sequencing profiles, enabling the elucidation of epithelial cell alterations during nodular formation. Immunofluorescent and immunohistochemical staining was performed for verification.

RESULTS

The alterations of epithelial cells during the formation of nodules in BPH was observed, and a distinct subgroup of basal epithelial (BE) cells, referred to as BE5, was identified to play a crucial role in driving this progression through the hypoxia-induced epithelial-mesenchymal transition (EMT) signaling pathway. BE5 served as both the initiating cell during nodular formation and the transitional cell during the transformation from luminal epithelial (LE) to BE cells. A distinguishing characteristic of the BE5 cell subgroup in patients with BPH was its heightened hypoxia and upregulated expression of FOS. Histological verification results confirmed a significant association between c-Fos expression and key biological processes such as hypoxia and cell proliferation, as well as the close relationship between hypoxia and EMT in BPH tissues. Furthermore, a strong link between c-Fos expression and the progression of BPH was also been validated. Additionally, notable functional differences were observed in glandular and stromal nodules regarding BE5 cells, with BE5 in glandular nodules exhibiting enhanced capacities for EMT and cell proliferation characterized by club-like cell markers.

CONCLUSIONS

This study elucidated the comprehensive landscape of epithelial cells during in vivo nodular formation in patients, thereby offering novel insights into the initiation and progression of BPH.

Forces at play: exploring factors affecting the cancer metastasis

Metastatic disease, a leading and lethal indication of deaths associated with tumors, results from the dissemination of metastatic tumor cells from the site of primary origin to a distant organ. Dispersion of metastatic cells during the development of tumors at distant organs leads to failure to comply with conventional treatments, ultimately instigating abrupt tissue homeostasis and organ failure. Increasing evidence indicates that the tumor microenvironment (TME) is a crucial factor in cancer progression and the process of metastatic tumor development at secondary sites. TME comprises several factors contributing to the initiation and progression of the metastatic cascade. Among these, various cell types in TME, such as mesenchymal stem cells (MSCs), lymphatic endothelial cells (LECs), cancer-associated fibroblasts (CAFs), myeloid-derived suppressor cells (MDSCs), T cells, and tumor-associated macrophages (TAMs), are significant players participating in cancer metastasis. Besides, various other factors, such as extracellular matrix (ECM), gut microbiota, circadian rhythm, and hypoxia, also shape the TME and impact the metastatic cascade. A thorough understanding of the functions of TME components in tumor progression and metastasis is necessary to discover new therapeutic strategies targeting the metastatic tumor cells and TME. Therefore, we reviewed these pivotal TME components and highlighted the background knowledge on how these cell types and disrupted components of TME influence the metastatic cascade and establish the premetastatic niche. This review will help researchers identify these altered components' molecular patterns and design an optimized, targeted therapy to treat solid tumors and restrict metastatic cascade.

Oncogenic role of FOXM1 in human prostate cancer (Review)

Prostate cancer is the leading cause of cancer‑related mortality among men worldwide. In particular, castration‑resistant prostate cancer presents a formidable clinical challenge and emphasizes the need to develop novel therapeutic strategies. Forkhead box M1 (FOXM1) is a multifaceted transcription factor that is implicated in the acquisition of the multiple cancer hallmark capabilities in prostate cancer cells, including sustaining proliferative signaling, resisting cell death and the activation of invasion and metastasis. Elevated FOXM1 expression is frequently observed in prostate cancer, and in particular, FOXM1 overexpression is closely associated with poor clinical outcomes in patients with prostate cancer. In the present review, recent advances in the understanding of the oncogenic role of deregulated FOXM1 expression in prostate cancer were highlighted. In addition, the molecular mechanisms by which FOXM1 regulates prostate cancer development and progression were described, thereby providing knowledge and a conceptual framework for FOXM1. The present review also provided valuable insight into the inherent challenges associated with translating biomedical knowledge into effective therapeutic strategies for prostate cancer.

E-box binding transcription factors in cancer

E-boxes are important regulatory elements in the eukaryotic genome. Transcription factors can bind to E-boxes through their basic helix-loop-helix or zinc finger domain to regulate gene transcription. E-box-binding transcription factors (EBTFs) are important regulators of development and essential for physiological activities of the cell. The fundamental role of EBTFs in cancer has been highlighted by studies on the canonical oncogene MYC, yet many EBTFs exhibit common features, implying the existence of shared molecular principles of how they are involved in tumorigenesis. A comprehensive analysis of TFs that share the basic function of binding to E-boxes has been lacking. Here, we review the structure of EBTFs, their common features in regulating transcription, their physiological functions, and their mutual regulation. We also discuss their converging functions in cancer biology, their potential to be targeted as a regulatory network, and recent progress in drug development targeting these factors in cancer therapy.

MiR-210 regulates lung adenocarcinoma by targeting HIF-1α

Object

This study sought to elucidate the role of microRNA-210 (miR-210) in the occurrence and development of lung adenocarcinoma (LUAD).

Methods

The levels of lncRNA miR-210HG and miR-210 in LUAD tissues and corresponding normal tissues were analyzed by real-time quantitative PCR. The expression of the anti-hypoxia factor hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were measured by qRT-PCR and Western blot. The target of miR-210 on HIF-1α was confirmed using TCGA, Western blot and luciferase reporter assay. The regulatory role of miR-210 on HIF-1α and VEGF in LUAD was investigated. The correlation of genes with clinical prognosis was analyzed using bioinformatics methods. The effect of miR-210 on LUAD cells was verified through apoptosis assays.

Results

The expression of miR-210 and miR-210HG was significantly higher in LUAD tissues than in normal tissues. The expression of hypoxia-related indicators HIF-1α and VEGF was also significantly higher in LUAD tissues. MiR-210 suppressed HIF-1α expression by targeting site 113 of HIF-1α, thereby affecting VEGF expression. Overexpression of miR-210 inhibited HIF-1 expression by targeting the 113 site of HIF-1, thereby affecting VEGF expression. Conversely, inhibition of miR-210 resulted in a significant increase in HIF-1α and VEGF expression in LUAD cells. In TCGA-LUAD cohorts, the expression of VEGF-c and VEGF-d genes in LUAD tissues was significantly lower than in normal tissues, while overall survival was worse in LUAD patients with high expression of HIF-1α, VEGF-c and VEGF-d. Apoptosis was significantly lower in H1650 cells after miR-210 inhibition.

Conclusion

This study reveals that miR-210 exerts an inhibitory effect on VEGF expression by down-regulating HIF-1α expression in LUAD. Conversely, inhibition of miR-210 significantly reduced H1650 apoptosis and led to worse patient survival by upregulating HIF-1α and VEGF. These results suggest that miR-210 could serve as a potential therapeutic target for the treatment of LUAD.

Targeting Mitochondrial ROS Production to Reverse the Epithelial-Mesenchymal Transition in Breast Cancer Cells

Experimental evidence implicates reactive oxygen species (ROS) generation in the hypoxic stabilization of hypoxia-inducible factor (HIF)-1α and in the subsequent expression of promoters of tumor invasiveness and metastatic spread. However, the role played by mitochondrial ROS in hypoxia-induced Epithelial-Mesenchymal Transition (EMT) activation is still unclear. This study was aimed at testing the hypothesis that the inhibition of hypoxia-induced mitochondrial ROS production, mainly at the mitochondrial Complex III UQCRB site, could result in the reversion of EMT, in addition to decreased HIF-1α stabilization. The role of hypoxia-induced ROS increase in HIF-1α stabilization and the ability of antioxidants, some of which directly targeting mitochondrial Complex III, to block ROS production and HIF-1α stabilization and prevent changes in EMT markers were assessed by evaluating ROS, HIF-1α and EMT markers on breast cancer cells, following 48 h treatment with the antioxidants. The specific role of UQCRB in hypoxia-induced EMT was also evaluated by silencing its expression through RNA interference and by assessing the effects of its downregulation on ROS production, HIF-1α levels, and EMT markers. Our results confirm the pivotal role of UQCRB in hypoxic signaling inducing EMT. Thus, UQCRB might be a new therapeutic target for the development of drugs able to reverse EMT by blocking mitochondrial ROS production.

Sirtuins and Hypoxia in EMT Control

Epithelial–mesenchymal transition (EMT), a physiological process during embryogenesis, can become pathological in the presence of different driving forces. Reduced oxygen tension or hypoxia is one of these forces, triggering a large number of molecular pathways with aberrant EMT induction, resulting in cancer and fibrosis onset. Both hypoxia-induced factors, HIF-1α and HIF-2α, act as master transcription factors implicated in EMT. On the other hand, hypoxia-dependent HIF-independent EMT has also been described. Recently, a new class of seven proteins with deacylase activity, called sirtuins, have been implicated in the control of both hypoxia responses, HIF-1α and HIF-2α activation, as well as EMT induction. Intriguingly, different sirtuins have different effects on hypoxia and EMT, acting as either activators or inhibitors, depending on the tissue and cell type. Interestingly, sirtuins and HIF can be activated or inhibited with natural or synthetic molecules. Moreover, recent studies have shown that these natural or synthetic molecules can be better conveyed using nanoparticles, representing a valid strategy for EMT modulation. The following review, by detailing the aspects listed above, summarizes the interplay between hypoxia, sirtuins, and EMT, as well as the possible strategies to modulate them by using a nanoparticle-based approach.

Present and Future Perspective on PLK1 Inhibition in Cancer Treatment

Polo-like kinase 1 (PLK1) is the principle member of the well conserved serine/threonine kinase family. PLK1 has a key role in the progression of mitosis and recent evidence suggest its important involvement in regulating the G2/M checkpoint, in DNA damage and replication stress response, and in cell death pathways. PLK1 expression is tightly spatially and temporally regulated to ensure its nuclear activation at the late S-phase, until the peak of expression at the G2/M-phase. Recently, new roles of PLK1 have been reported in literature on its implication in the regulation of inflammation and immunological responses. All these biological processes are altered in tumors and, considering that PLK1 is often found overexpressed in several tumor types, its targeting has emerged as a promising anti-cancer therapeutic strategy. In this review, we will summarize the evidence suggesting the role of PLK1 in response to DNA damage, including DNA repair, cell cycle progression, epithelial to mesenchymal transition, cell death pathways and cancer-related immunity. An update of PLK1 inhibitors currently investigated in preclinical and clinical studies, in monotherapy and in combination with existing chemotherapeutic drugs and targeted therapies will be discussed.

FAT10 promotes chemotherapeutic resistance in pancreatic cancer by inducing epithelial-mesenchymal transition via stabilization of FOXM1 expression

Pancreatic cancer (PC) is one of the deadliest malignant tumors, and its resistance to gemcitabine chemotherapy is the primary reason for poor prognosis in patients. Ubiquitin-like protein FAT10 has recently been reported to promote tumor chemotherapy resistance. In this study, the expression of FAT10 in PC was significantly higher than that in adjacent noncancerous tissues. Increased expression of FAT10 in PC was related to a late TNM stage and decreased overall survival. Functional experiments revealed that downregulating the expression of FAT10 inhibits the proliferation and epithelial-mesenchymal transition (EMT) of PC cells, promotes the apoptosis of PC cells, and enhances sensitivity to gemcitabine chemotherapy. In addition, upregulation of FAT10 increased the expression of FOXM1 protein. The effect of downregulating FAT10 was reversed by FOXM1 overexpression, and FOXM1 knockdown inhibited EMT driven by FAT10 overexpression. Mechanistically, FAT10 stabilized the expression of FOXM1 by competing with ubiquitin to bind FOXM1 and inhibiting the ubiquitination-mediated degradation of FOXM1. In conclusion, the FAT10-FOXM1 axis is a pivotal driver of PC proliferation and gemcitabine resistance, and the results provide novel insights into chemotherapy resistance in PC.

A novel HIF1α-STIL-FOXM1 axis regulates tumor metastasis

BACKGROUND

Metastasis is the major cause of morbidity and mortality in cancer that involves in multiple steps including epithelial-mesenchymal transition (EMT) process. Centrosome is an organelle that functions as the major microtubule organizing center (MTOC), and centrosome abnormalities are commonly correlated with tumor aggressiveness. However, the conclusive mechanisms indicating specific centrosomal proteins participated in tumor progression and metastasis remain largely unknown.

METHODS

The expression levels of centriolar/centrosomal genes in various types of cancers were first examined by in silico analysis of the data derived from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and European Bioinformatics Institute (EBI) datasets. The expression of STIL (SCL/TAL1-interrupting locus) protein in clinical specimens was further assessed by Immunohistochemistry (IHC) analysis and the oncogenic roles of STIL in tumorigenesis were analyzed using in vitro and in vivo assays, including cell migration, invasion, xenograft tumor formation, and metastasis assays. The transcriptome differences between low- and high-STIL expression cells were analyzed by RNA-seq to uncover candidate genes involved in oncogenic pathways. The quantitative polymerase chain reaction (qPCR) and reporter assays were performed to confirm the results. The chromatin immunoprecipitation (ChIP)-qPCR assay was applied to demonstrate the binding of transcriptional factors to the promoter.

RESULTS

The expression of STIL shows the most significant increase in lung and various other types of cancers, and is highly associated with patients' survival rate. Depletion of STIL inhibits tumor growth and metastasis. Interestingly, excess STIL activates the EMT pathway, and subsequently enhances cancer cell migration and invasion. Importantly, we reveal an unexpected role of STIL in tumor metastasis. A subset of STIL translocate into nucleus and associate with FOXM1 (Forkhead box protein M1) to promote tumor metastasis and stemness via FOXM1-mediated downstream target genes. Furthermore, we demonstrate that hypoxia-inducible factor 1α (HIF1α) directly binds to the STIL promoter and upregulates STIL expression under hypoxic condition.

CONCLUSIONS

Our findings indicate that STIL promotes tumor metastasis through the HIF1α-STIL-FOXM1 axis, and highlight the importance of STIL as a promising therapeutic target for lung cancer treatment.

Insight into Hypoxia Stemness Control

Recently, the research on stemness and multilineage differentiation mechanisms has greatly increased its value due to the potential therapeutic impact of stem cell-based approaches. Stem cells modulate their self-renewing and differentiation capacities in response to endogenous and/or extrinsic factors that can control stem cell fate. One key factor controlling stem cell phenotype is oxygen (O₂). Several pieces of evidence demonstrated that the complexity of reproducing O₂ physiological tensions and gradients in culture is responsible for defective stem cell behavior in vitro and after transplantation. This evidence is still worsened by considering that stem cells are conventionally incubated under non-physiological air O₂ tension (21%). Therefore, the study of mechanisms and signaling activated at lower O₂ tension, such as those existing under native microenvironments (referred to as hypoxia), represent an effective strategy to define if O₂ is essential in preserving naïve stemness potential as well as in modulating their differentiation. Starting from this premise, the goal of the present review is to report the status of the art about the link existing between hypoxia and stemness providing insight into the factors/molecules involved, to design targeted strategies that, recapitulating naïve O₂ signals, enable towards the therapeutic use of stem cell for tissue engineering and regenerative medicine.

STK10 knockout inhibits cell migration and promotes cell proliferation via modulating the activity of ERM and p38 MAPK in prostate cancer cells

Prostate cancer (PCa) is one of the most common types of cancer and is a serious threat to men's health due to the high rate of incidence and metastasis. However, the exact underlying pathology of this malignant disease has yet to be fully elucidated. The ezrin-radixin-moesin (ERM) family of proteins are associated with the development and metastasis of various types of cancer. Serine threonine kinase 10 (STK10) is an ERM kinase that is involved in the activation of ERM proteins and serves essential roles in the aggregation and adhesion of lymphocytes. To evaluate the functional roles of STK10 in the pathogenesis of PCa, a STK10-knockout (KO) DU145 PCa cell line was generated using the CRISPR-Cas9 gene editing system, and the effects of STK10 deletion on tumor biological behaviors were further analyzed. The present data suggested that STK10 KO promoted PCa cell proliferation by inhibiting p38 MAPK activation and suppressed migration primarily via the inhibition of p38 MAPK signaling and ERM protein activation. To the best of our knowledge, this is the first study to provide evidence that STK10 plays important roles in the proliferation and migration of PCa cells, which will be useful for further investigation into the pathogenesis of this disease.

The epithelial-mesenchymal transition regulators Twist, Slug, and Snail are associated with aggressive tumour features and poor outcome in prostate cancer patients

The prognostic importance of transcription factors promoting epithelial-mesenchymal transition (EMT) and angiogenesis has not been well explored in prostate cancer patients with long follow-up, nor the interplay between these factors. The objective of this study was to assess the individual protein expression and co-expression of Twist, Slug (Snai2), Snail (Snai1), and hypoxia-inducible factor-1 alpha (Hif-1α) in prostate cancer in relation to EMT, angiogenesis, hypoxia, tumour features, disease recurrence, and patient survival. Immunohistochemical staining was performed on tissue microarray sections from 338 radical prostatectomies with long follow-up. In addition, 41 cases of prostatic hyperplasia, 33 non-skeletal metastases, 13 skeletal metastases, and 33 castration-resistant prostate carcinomas were included. Our findings were validated in external gene expression data sets. Twist was overexpressed in primary prostate cancer and markedly reduced in distant metastases (p < 0.0005). Strong expression of Twist and Slug was associated with Hif-1α in localised prostate cancer (p ≤ 0.001), and strong Twist was associated with Hif-1α in castration-resistant carcinomas (p = 0.044). Twist, Slug, and increased Snail at the tumour stromal border were associated with vascular factors (p ≤ 0.045). Each of the three EMT-regulating transcription factors were associated with aggressive tumour features and shorter time to recurrence and cancer-specific death. Notably, the co-expression of factors demonstrated an enhanced influence on outcome. In the subgroup of E-cadherinlow carcinomas, strong Slug was associated with shorter time to all end points and was an independent predictor of time to multiple end points, including cancer-specific death (hazard ratio 3.0, p = 0.041). To conclude, we demonstrate an important relation between EMT, hypoxia, and angiogenesis and a strong link between the investigated EMT regulators and aggressive tumour features and poor patient outcome in prostate cancer. Despite the retrospective nature of this long-term study, our findings could have a significant impact on the future treatment of prostate cancer, where tailored therapies might be directed simultaneously against epithelial-mesenchymal phenotypes, angiogenesis, and tumour hypoxia.

Amnion-Derived Teno-Inductive Secretomes: A Novel Approach to Foster Tendon Differentiation and Regeneration in an Ovine Model

Regenerative medicine has greatly progressed, but tendon regeneration mechanisms and robust in vitro tendon differentiation protocols remain to be elucidated. Recently, tendon explant co-culture (CO) has been proposed as an in vitro model to recapitulate the microenvironment driving tendon development and regeneration. Here, we explored standardized protocols for production and storage of bioactive tendon-derived secretomes with an evaluation of their teno-inductive effects on ovine amniotic epithelial cells (AECs). Teno-inductive soluble factors were released in culture-conditioned media (CM) only in response to active communication between tendon explants and stem cells (CMCO). Unsuccessful tenogenic differentiation in AECs was noted when exposed to CM collected from tendon explants (CMFT) only, whereas CMCO upregulated SCXB, COL I and TNMD transcripts, in AECs, alongside stimulation of the development of mature 3D tendon-like structures enriched in TNMD and COL I extracellular matrix proteins. Furthermore, although the tenogenic effect on AECs was partially inhibited by freezing CMCO, this effect could be recovered by application of an in vivo-like physiological oxygen (2% O2) environment during AECs tenogenesis. Therefore, CMCO can be considered as a waste tissue product with the potential to be used for the development of regenerative bio-inspired devices to innovate tissue engineering application to tendon differentiation and healing.

The Effect of Hypoxia on the Expression of CXC Chemokines and CXC Chemokine Receptors-A Review of Literature

Hypoxia is an integral component of the tumor microenvironment. Either as chronic or cycling hypoxia, it exerts a similar effect on cancer processes by activating hypoxia-inducible factor-1 (HIF-1) and nuclear factor (NF-κB), with cycling hypoxia showing a stronger proinflammatory influence. One of the systems affected by hypoxia is the CXC chemokine system. This paper reviews all available information on hypoxia-induced changes in the expression of all CXC chemokines (CXCL1, CXCL2, CXCL3, CXCL4, CXCL5, CXCL6, CXCL7, CXCL8 (IL-8), CXCL9, CXCL10, CXCL11, CXCL12 (SDF-1), CXCL13, CXCL14, CXCL15, CXCL16, CXCL17) as well as CXC chemokine receptors—CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CXCR7 and CXCR8. First, we present basic information on the effect of these chemoattractant cytokines on cancer processes. We then discuss the effect of hypoxia-induced changes on CXC chemokine expression on the angiogenesis, lymphangiogenesis and recruitment of various cells to the tumor niche, including myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), regulatory T cells (T_regs) and tumor-infiltrating lymphocytes (TILs). Finally, the review summarizes data on the use of drugs targeting the CXC chemokine system in cancer therapies.

High expression of hypoxia inducible factor 1α related with acquired resistant to EGFR tyrosine kinase inhibitors in NSCLC

The acquired resistance of the first generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is a main factor leading to poor prognosis of non-small cell lung cancer (NSCLC), so we researched whether the high expression of hypoxia-inducible factor-1α (HIF-1α) in EGFR-TKIs sensitive NSCLC tissue tends to induce the acquired resistance. We detected the HIF-1α in normal lung tissue, EGFR-TKIs sensitive NSCLC tissue, the first generation EGFR-TKIs acquired resistant NSCLC tissue and acquired EGFR T790M mutation NSCLC tissue with the method of immunohistochemistry. Then, we compared the expression of HIF-1α in these tissues, and evaluate the effect of HIF-1α expression to the occurrence of acquired resistance. The expression of HIF-1α was much higher in the EGFR-TKIs sensitive NSCLC tissue than that in normal lung tissue. HIF-1α level became higher after the occurrence acquired resistance. There was negative correlation between HIF-1α level before receiving treatment and the time of acquired resistance occurring as well as the acquired EGFR T790M mutation occurring. As the treatment going on, EGFR-TKIs sensitivity rate of low HIF-1α level group was much higher than that of high level group. The high expression of HIF-1α related with the acquired resistance of the first generation EGFR-TKIs, and HIF-1α can be a biomarker to predict the early occurrence of acquired resistance.

Impact of Lineage Plasticity to and from a Neuroendocrine Phenotype on Progression and Response in Prostate and Lung Cancers

Intratumoral heterogeneity can occur via phenotype transitions, often after chronic exposure to targeted anticancer agents. This process, termed lineage plasticity, is associated with acquired independence to an initial oncogenic driver, resulting in treatment failure. In non-small cell lung cancer (NSCLC) and prostate cancers, lineage plasticity manifests when the adenocarcinoma phenotype transforms into neuroendocrine (NE) disease. The exact molecular mechanisms involved in this NE transdifferentiation remain elusive. In small cell lung cancer (SCLC), plasticity from NE to nonNE phenotypes is driven by NOTCH signaling. Herein we review current understanding of NE lineage plasticity dynamics, exemplified by prostate cancer, NSCLC, and SCLC.

Targeting tumor-associated macrophages in the tumor microenvironment

Tumor-associated macrophages (TAMs) are the most abundant population type of tumor-infiltrating immune cells found in the tumor microenvironment (TME), and are evolutionarily associated with microvessel density in tumor tissues. TAMs can be broadly divided into M1-like and M2-like TAMs, which demonstrate antitumor and pro-tumor activity in the TME, respectively. Studies have indicated that: i) The predominate presence of M2-like TAMs in the TME can result in tumor immunosuppression and chemoresistance; ii) the ratio of M1-like to M2-like TAMs in the TME is positively correlated with better long-term prognosis of patients with cancer; iii) epigenetic silencing, preventing the secretion of M1-like TAM-associated molecules, is an important immune evasion mechanism during tumor progression; and iv) the transformation from M2-like to M1-like TAMs following exposure to specific conditions can result in tumor regression. The present study discusses the molecular events underlying the recruitment of macrophages and their polarization into M1-like or M2-like TAMs, and their differential roles in angiogenesis, angiostasis, invasion, metastasis and immune activity in the TME. This insight may inform the improved design of TAM-targeted cancer immunotherapy. Some of these therapeutic strategies show promising effects; however, challenges remain.

Hypoxia-Induced Epithelial-Mesenchymal Transition in Cancers: HIF-1α and Beyond

Metastasis is the main cause of cancer-related mortality. Although the actual process of metastasis remains largely elusive, epithelial-mesenchymal transition (EMT) has been considered as a major event in metastasis. Besides, hypoxia is common in solid cancers and has been considered as an important factor for adverse treatment outcomes including metastasis. Since EMT and hypoxia potentially share several signaling pathways, many recent studies focused on investigate the issue of hypoxia-induced EMT. Among all potential mediators of hypoxia-induced EMT, hypoxia-inducible factor-1α (HIF-1α) has been studied extensively. Moreover, there are other potential mediators that may also contribute to the process. This review aims to summarize the recent reports on hypoxia-induced EMT by HIF-1α or other potential mediators and provide insights for further investigations on this issue. Ultimately, better understanding of hypoxia-induced EMT may allow us to develop anti-metastatic strategies and improve treatment outcomes.

Integrative Analysis of Breast Cancer Cells Reveals an Epithelial-Mesenchymal Transition Role in Adaptation to Acidic Microenvironment

Early ducts of breast tumors are unequivocally acidic. High rates of glycolysis combined with poor perfusion lead to a congestion of acidic metabolites in the tumor microenvironment, and pre-malignant cells must adapt to this acidosis to thrive. Adaptation to acidosis selects cancer cells that can thrive in harsh conditions and are capable of outgrowing the normal or non-adapted neighbors. This selection is usually accompanied by phenotypic change. Epithelial mesenchymal transition (EMT) is one of the most important switches correlated to malignant tumor cell phenotype and has been shown to be induced by tumor acidosis. New evidence shows that the EMT switch is not a binary system and occurs on a spectrum of transition states. During confirmation of the EMT phenotype, our results demonstrated a partial EMT phenotype in our acid-adapted cell population. Using RNA sequencing and network analysis we found 10 dysregulated network motifs in acid-adapted breast cancer cells playing a role in EMT. Our further integrative analysis of RNA sequencing and SILAC proteomics resulted in recognition of S100B and S100A6 proteins at both the RNA and protein level. Higher expression of S100B and S100A6 was validated in vitro by Immunocytochemistry. We further validated our finding both in vitro and in patients' samples by IHC analysis of Tissue Microarray (TMA). Correlation analysis of S100A6 and LAMP2b as marker of acidosis in each patient from Moffitt TMA approved the acid related role of S100A6 in breast cancer patients. Also, DCIS patients with higher expression of S100A6 showed lower survival compared to lower expression. We propose essential roles of acid adaptation in cancer cells EMT process through S100 proteins such as S100A6 that can be used as therapeutic strategy targeting both acid-adapted and malignant phenotypes.

Suppression of TRPM7 Inhibited Hypoxia-Induced Migration and Invasion of Androgen-Independent Prostate Cancer Cells by Enhancing RACK1-Mediated Degradation of HIF-1α

Transient receptor potential melastatin subfamily member 7 (TRPM7) was essential in the growth and metastatic ability of prostate cancer cells. However, the effects and the relevant molecular mechanisms of TRPM7 on metastasis of prostate cancer under hypoxic atmosphere remain unclear. This study investigated the role of TRPM7 in the metastatic ability of androgen-independent prostate cancer cells under hypoxia. First, data mining was carried out to disclose the relationship between the TRPM7 gene level and the survival of prostate cancer patients. Specific siRNAs were used to knockdown target genes. Western blotting and qPCR were employed to determine protein and gene expression, respectively. The gene transcription activity was evaluated by luciferase activity assay of promoter gene. The protein interaction was determined by coimmunoprecipitation. Wound healing and transwell assays were employed to evaluated cell migration and invasion, respectively. Open access database results showed that high expression of TRPM7 was closely related to the poor survival of prostate cancer patients. Hypoxia simultaneously increased TRPM7 expression and induced HIF-1α accumulation in androgen-independent prostate cancer cells. Knockdown of TRPM7 significantly promoted HIF-1α degradation through the proteasome and inhibited EMT changes in androgen-independent prostate cancer cells under hypoxic condition. Moreover, TRPM7 knockdown increased the phosphorylation of RACK1 and strengthened the interaction between RACK1 and HIF-1α but attenuated the binding of HSP90 to HIF-1α. Whereas knockdown of RACK1 increased the binding of HSP90 to HIF-1α. Furthermore, both TRPM7 and HIF-1α knockdown significantly suppressed hypoxia-induced Annexin A1 protein expression, and suppression of HIF-1α/Annexin A1 signaling significantly inhibited hypoxia-induced cell migration and invasion of androgen-independent prostate cancer cells. Our findings demonstrate that TRPM7 knockdown promotes HIF-1α degradation via an oxygen-independent mechanism involving increased binding of RAKC1 to HIF-1α, and TRPM7-HIF-1α-Annexin A1 signaling axis plays a crucial role in the EMT, cell migration, and invasion of androgen-independent prostate cancer cells under hypoxic conditions.