The STAT3-miRNA-92-Wnt Signaling Pathway Regulates Spheroid Formation and Malignant Progression in Ovarian Cancer

Metabolic adaptation in epithelial ovarian cancer metastasis

Epithelial ovarian cancer (EOC) is highly lethal due to its unique metastatic characteristics. EOC spheroids enter a non-proliferative state, with hypoxic cores and reduced oncogenic signaling, all of which contribute to tumour dormancy during metastasis. We investigated the metabolomic states of EOC cells progressing through the three steps to metastasis. Metabolomes of adherent, spheroid, and re-adherent cells were validated by isotopic metabolic flux analysis and mitochondrial functional assays to identify metabolic pathways that were previously unknown to promote EOC metastasis. Although spheroids were thought to exist in a dormant state, metabolomic analysis revealed an unexpected upregulation of energy production pathways in spheroids, accompanied by increased abundance of tricarboxylic acid (TCA) cycle and electron transport chain proteins. Tracing of 13C-labelled glucose and glutamine showed increased pyruvate carboxylation and decreased glutamine anaplerosis in spheroids. Increased reductive carboxylation suggests spheroids adjust redox homeostasis by shuttling cytosolic NADPH into mitochondria via isocitrate dehydrogenase. Indeed, we observed spheroids have increased respiratory capacity and mitochondrial ATP production. Relative to adherent cells, spheroids reduced serine consumption and metabolism, processes which were reversed upon spheroid re-adherence. The data reveal a distinct metabolism in EOC spheroids that enhances energy production by the mitochondria while maintaining a dormant state with respect to growth and proliferation. The findings advance our understanding of EOC metastasis and identify the TCA cycle and mitochondrional activity as novel targets to disrupt EOC metastasis, providing new approaches to treat advanced disease.

Netrin signaling mediates survival of dormant epithelial ovarian cancer cells

Dormancy in cancer is a clinical state in which residual disease remains undetectable for a prolonged duration. At a cellular level, rare cancer cells cease proliferation and survive chemotherapy and disseminate disease. We created a suspension culture model of high-grade serous ovarian cancer (HGSOC) dormancy and devised a novel CRISPR screening approach to identify survival genes in this context. In combination with RNA-seq, we discovered the Netrin signaling pathway as critical to dormant HGSOC cell survival. We demonstrate that Netrin-1, -3, and its receptors are essential for low level ERK activation to promote survival, and that Netrin activation of ERK is unable to induce proliferation. Deletion of all UNC5 family receptors blocks Netrin signaling in HGSOC cells and compromises viability during the dormancy step of dissemination in xenograft assays. Furthermore, we demonstrate that Netrin-1 and -3 overexpression in HGSOC correlates with poor outcome. Specifically, our experiments reveal that Netrin overexpression elevates cell survival in dormant culture conditions and contributes to greater spread of disease in a xenograft model of abdominal dissemination. This study highlights Netrin signaling as a key mediator HGSOC cancer cell dormancy and metastasis.

GLUT3 transcriptional activation by ZEB1 fuels the Warburg effect and promotes ovarian cancer progression

Ovarian cancer (OvCa) is characterized by early metastasis and high mortality rates, underscoring the need for deeper understanding of these aspects. This study explores the role of glucose transporter 3 (GLUT3) driven by zinc finger E-box-binding homeobox 1 (ZEB1) in OvCa progression and metastasis. Specifically, this study explored whether ZEB1 promotes glycolysis and assessed the potential involvement of GLUT3 in this process in OvCa cells. Our findings revealed that ZEB1 and GLUT3 were excessively expressed and closely correlated in OvCa. Mechanistically, ZEB1 activates the transcription of GLUT3 by binding to its promoter region. Increased expression of GLUT3 driven by ZEB1 dramatically enhances glycolysis, and thus fuels Warburg Effect to promote OvCa progression and metastasis. Consistently, elevated ZEB1 and GLUT3 expression in clinical OvCa is correlated with poor prognosis, reinforcing the profound contribution of ZEB1-GLUT3 axis to OvCa. These results suggest that activation of GLUT3 expression by ZEB1 is crucial for the proliferation and metastasis of OvCa via fueling glycolysis, shedding new light on OvCa treatment.

Sindbis Virus Vaccine Platform: A Promising Oncolytic Virus-Mediated Approach for Ovarian Cancer Treatment

This review article provides a comprehensive overview of a novel Sindbis virus vaccine platform as potential immunotherapy for ovarian cancer patients. Ovarian cancer is the most lethal of all gynecological malignancies. The majority of high-grade serous ovarian cancer (HGSOC) patients are diagnosed with advanced disease. Current treatment options are very aggressive and limited, resulting in tumor recurrences and 50-60% patient mortality within 5 years. The unique properties of armed oncolytic Sindbis virus vectors (SV) in vivo have garnered significant interest in recent years to potently target and treat ovarian cancer. We discuss the molecular biology of Sindbis virus, its mechanisms of action against ovarian cancer cells, preclinical in vivo studies, and future perspectives. The potential of Sindbis virus-based therapies for ovarian cancer treatment holds great promise and warrants further investigation. Investigations using other oncolytic viruses in preclinical studies and clinical trials are also presented.

WP1066, a small molecule inhibitor of STAT3, chemosensitizes paclitaxel-resistant ovarian cancer cells to paclitaxel by simultaneously inhibiting the activity of STAT3 and the interaction of STAT3 with Stathmin

Paclitaxel is widely used to treat cancer, however, drug resistance limits its clinical utility. STAT3 is constitutively activated in some cancers, and contributes to chemotherapy resistance. Currently, several STAT3 inhibitors including WP1066 are used in cancer clinical trials. However, whether WP1066 reverses paclitaxel resistance and the mechanismremains unknown. Here, we report that in contrast to paclitaxel-sensitive parental cells, the expressions of several pro-survival BCL2 family members such as BCL-2, BCL-XL and MCL-1 are higher in paclitaxel-resistant ovarian cancer cells. Meanwhile, STAT3 is constitutively activated while stathmin loses its activity in paclitaxel-resistant cells. Importantly, WP1066 amplifies the inhibition of cell proliferation, colony-forming ability and apoptosis of ovarian cancer cells induced by paclitaxel. Mechanistically, WP1066, on the one hand, interferes the STAT3/Stathmin interaction, causing unleash of STAT3/Stathmin from microtubule, thus destroying microtubule stability. This process results in reduction of Ac-α-tubulin, further causing MCL-1 reduction. On the other hand, WP1066 inhibits phosphorylation of STAT3 by JAK2, and blocks its nuclear translocation, therefore repressing the transcription of pro-survival targets such as BCL-2, BCL-XL and MCL-1. Finally, the two pathways jointly promote cell death. Our findings reveal a new mechanism wherein WP1066 reverses paclitaxel-resistance of ovarian cancer cells by dually inhibiting STAT3 activity and STAT3/Stathmin interaction, which may layfoundation for WP1066 combined with paclitaxel in treating paclitaxel-resistant ovarian cancer.

miRNA on the Battlefield of Cancer: Significance in Cancer Stem Cells, WNT Pathway, and Treatment

Carcinogenesis is a complex process characterized by intricate changes in organ histology, biochemistry, epigenetics, and genetics. Within this intricate landscape, cancer stem cells (CSCs) have emerged as distinct cell types possessing unique attributes that significantly contribute to the pathogenesis of cancer. The WNT signaling pathway plays a critical role in maintaining somatic stem cell pluripotency. However, in cancer, overexpression of WNT mediators enhances the activity of β-catenin, resulting in phenomena such as recurrence and unfavorable survival outcomes. Notably, CSCs exhibit heightened WNT signaling compared to bulk cancer cells, providing intriguing insights into their functional characteristics. MicroRNAs (miRNAs), as post-transcriptional gene expression regulators, modulate various physiological processes in numerous diseases including cancer. Upregulation or downregulation of miRNAs can affect the production of pro-oncogenic or anti-oncogenic proteins, influencing cellular processes that maintain tissue homeostasis and promote either apoptosis or differentiation, even in cancer cells. In order to understand the dysregulation of miRNAs, it is essential to examine miRNA biogenesis and any possible alterations at each step. The potential of a miRNA as a biomarker in prognosis, diagnosis, and detection is being assessed using technologies such as next-generation sequencing. Extensive research has explored miRNA expression profiles in cancer, leading to their utilization as diagnostic tools and the development of personalized and targeted cancer therapies. This review delves into the role of miRNAs in carcinogenesis in relation to the WNT signaling pathway along with their potential as druggable compounds.

The regulatory mechanisms of oncomiRs in cancer

Cancer development is a complex process that primarily results from the combination of genetic alterations and the dysregulation of major signalling pathways due to interference with the epigenetic machinery. As major epigenetic regulators, miRNAs are central players in the control of many key tumour development factors. These miRNAs have been classified as oncogenic miRNAs (oncomiRs) when they target tumour suppressor genes and tumour suppressor miRNAs (TS miRNAs) when they inhibit oncogene protein expression. Most of the mechanisms that modulate oncomiR expression are linked to transcriptional or posttranscriptional regulation. However, non-transcriptional processes, such as gene amplification, have been described as alternative processes that are responsible for increasing oncomiR expression. The current review summarises the different mechanisms controlling the upregulation of oncomiR expression in cancer cells and the tumour microenvironment (TME). Detailed knowledge of the mechanism underlying the regulation of oncomiR expression in cancer may pave the way for understanding the critical role of oncomiRs in cancer development and progression.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Oligonucleotide-Based Therapeutics for STAT3 Targeting in Cancer-Drug Carriers Matter

High expression and phosphorylation of signal transducer and transcription activator 3 (STAT3) are correlated with progression and poor prognosis in various types of cancer. The constitutive activation of STAT3 in cancer affects processes such as cell proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. The importance of STAT3 in cancer makes it a potential therapeutic target. Various methods of directly and indirectly blocking STAT3 activity at different steps of the STAT3 pathway have been investigated. However, the outcome has been limited, mainly by the number of upstream proteins that can reactivate STAT3 or the relatively low specificity of the inhibitors. A new branch of molecules with significant therapeutic potential has emerged thanks to recent developments in the regulatory function of non-coding nucleic acids. Oligonucleotide-based therapeutics can silence target transcripts or edit genes, leading to the modification of gene expression profiles, causing cell death or restoring cell function. Moreover, they can reach untreatable targets, such as transcription factors. This review briefly describes oligonucleotide-based therapeutics that found application to target STAT3 activity in cancer. Additionally, this review comprehensively summarizes how the inhibition of STAT3 activity by nucleic acid-based therapeutics such as siRNA, shRNA, ASO, and ODN-decoy affected the therapy of different types of cancer in preclinical and clinical studies. Moreover, due to some limitations of oligonucleotide-based therapeutics, the importance of carriers that can deliver nucleic acid molecules to affect the STAT3 in cancer cells and cells of the tumor microenvironment (TME) was pointed out. Combining a high specificity of oligonucleotide-based therapeutics toward their targets and functionalized nanoparticles toward cell type can generate very efficient formulations.

Genetic and Functional Modifications Associated with Ovarian Cancer Cell Aggregation and Limited Culture Conditions

The aggregation of cancer cells provides a survival signal for disseminating cancer cells; however, the underlying molecular mechanisms have yet to be elucidated. Using qPCR gene arrays, this study investigated the changes in cancer-specific genes as well as genes regulating mitochondrial quality control, metabolism, and oxidative stress in response to aggregation and hypoxia in our progressive ovarian cancer models representing slow- and fast-developing ovarian cancer. Aggregation increased the expression of anti-apoptotic, stemness, epithelial-mesenchymal transition (EMT), angiogenic, mitophagic, and reactive oxygen species (ROS) scavenging genes and functions, and decreased proliferation, apoptosis, metabolism, and mitochondrial content genes and functions. The incorporation of stromal vascular cells (SVF) from obese mice into the spheroids increased DNA repair and telomere regulatory genes that may represent a link between obesity and ovarian cancer risk. While glucose had no effect, glutamine was essential for aggregation and supported proliferation of the spheroid. In contrast, low glucose and hypoxic culture conditions delayed adhesion and outgrowth capacity of the spheroids independent of their phenotype, decreased mitochondrial mass and polarity, and induced a shift of mitochondrial dynamics towards mitophagy. However, these conditions did not reduce the appearance of polarized mitochondria at adhesion sites, suggesting that adhesion signals that either reversed mitochondrial fragmentation or induced mitobiogenesis can override the impact of low glucose and oxygen levels. Thus, the plasticity of the spheroids' phenotype supports viability during dissemination, allows for the adaptation to changing conditions such as oxygen and nutrient availability. This may be critical for the development of an aggressive cancer phenotype and, therefore, could represent druggable targets for clinical interventions.

Blockade of the SRC/STAT3/BCL-2 Signaling Axis Sustains the Cytotoxicity in Human Colorectal Cancer Cell Lines Induced by Dehydroxyhispolon Methyl Ether

Colorectal cancer (CRC) is the third most prevalent human cancer globally. 5-Fluorouracil (5-FU)-based systemic chemotherapy is the primary strategy for advanced CRC treatment, yet is limited by poor response rate. Deregulated activation of signal transducer and activator of transcription 3 (STAT3) is fundamental to driving CRC malignant transformation and a poor prognostic marker for CRC, underscoring STAT3 as a promising CRC drug target. Dehydroxyhispolon methyl ether (DHME) is an analog of Hispolon, an anticancer polyphenol abundant in the medicinal mushroom Phellinus linteus. Previously, we have established DHME's cytotoxic effect on human CRC cell lines by eliciting apoptosis through the blockade of WNT/β-catenin signaling, a preeminent CRC oncogenic pathway. Herein, we unraveled that compared with 5-FU, DHME is a more potent killer of CRC cells while being much less toxic to normal colon epithelial cells. DHME suppressed both constitutive and interleukin 6 (IL-6)-induced STAT3 activation represented by tyrosine 705 phosphorylation of STAT3 (p-STAT3 (Y705)); notably, DHME-induced CRC apoptosis and clonogenicity limitation were abrogated by ectopic expression of STAT3-C, a dominant-active STAT3 mutant. Additionally, we proved that BCL-2 downregulation caused by DHME-mediated STAT3 blockage is responsible for DHME-induced CRC cell apoptosis. Lastly, DHME inhibited SRC activation, and v-src overexpression restored p-STAT3 (Y705) levels along with lowering the levels of apoptosis in DHME-treated CRC cells. We conclude DHME provokes CRC cell apoptosis by blocking the SRC/STAT3/BCL-2 axis besides thwarting WNT/β-catenin signaling. The notion that DHME targets two fundamental CRC signaling pathways underpins the potential of DHME as a CRC chemotherapy agent.

AUF1-induced circular RNA hsa_circ_0010467 promotes platinum resistance of ovarian cancer through miR-637/LIF/STAT3 axis

BACKGROUND

Increasing evidences has indicated that primary and acquired resistance of ovarian cancer (OC) to platinum is mediated by multiple molecular and cellular factors. Understanding these mechanisms could promote the therapeutic efficiency for patients with OC.

METHODS

Here, we screened the expression pattern of circRNAs in samples derived from platinum-resistant and platinum-sensitive OC patients using RNA-sequencing (RNA-seq). The expression of hsa_circ_0010467 was validated by Sanger sequencing, RT-qPCR, and fluorescence in situ hybridization (FISH) assays. Overexpression and knockdown experiments were performed to explore the function of hsa_circ_0010467. The effects of hsa_circ_0010467 on enhancing platinum treatment were validated in OC cells, mouse model and patient-derived organoid (PDO). RNA pull-down, RNA immunoprecipitation (RIP), and dual-luciferase reporter assays were performed to investigate the interaction between hsa_circ_0010467 and proteins.

RESULTS

Increased expression of hsa_circ_0010467 is observed in platinum-resistant OC cells, tissues and serum exosomes, which is positively correlated with advanced tumor stage and poor prognosis of OC patients. Hsa_circ_0010467 is found to maintain the platinum resistance via inducing tumor cell stemness, and silencing hsa_circ_0010467 substantially increases the efficacy of platinum treatment on inhibiting OC cell proliferation. Further investigation reveals that hsa_circ_0010467 acts as a miR-637 sponge to mediate the repressive effect of miR-637 on leukemia inhibitory factor (LIF) and activates the LIF/STAT3 signaling pathway. We further discover that AUF1 could promote the biogenesis of hsa_circ_0010467 in OC.

CONCLUSION

Our study uncovers the mechanism that hsa_circ_0010467 mediates the platinum resistance of OC through AUF1/hsa_circ_0010467/miR-637/LIF/STAT3 axis, and provides potential targets for the treatment of platinum-resistant OC patients.

Delta/Notch-like Epidermal Growth Factor-Related Receptor (DNER), a Potential Prognostic Marker of Gastric Cancer Regulates Cell Survival and Cell Cycle Progression

Upregulation of the expression of Delta/notch-like epidermal growth factor-related receptor (DNER) and its oncogenic role have been reported in several cancers, including gastric, breast, and prostate cancers. This study aimed to investigate the oncogenic role of DNER and the mechanisms behind its oncogenic role in gastric cancer. Analysis of the RNASeq data of gastric cancer tissues obtained from the TCGA database revealed that the expression of DNER was associated with the pathology of advanced gastric cancer and the prognosis of patients. DNER expression was increased upon stem cell-enriching cancer spheroid culture. Knockdown of DNER expression inhibited cell proliferation and invasion, induced apoptosis, enhanced chemosensitivity, and decreased spheroid formation of SNU-638 gastric cancer cells. DNER silencing elevated the expression of p53, p21^cip/waf, and p27, and increased G₁ phase cells at the expense of S phase cells. Knockdown of p21^cip/waf expression in the DNER-silenced cells partially restored cell viability and S phase progression. DNER silencing also induced the apoptosis of SNU-638 cells. While both cleaved caspases-8 and 9 were detected in adherent cells, only cleaved caspase-8 was found to have increased in spheroid-cultured cells, suggesting a distinct activation pattern of caspase activation depending on the growth condition. Knockdown of p53 expression rescued the DNER-silenced cells from apoptosis and partially restored cell viability. In contrast, overexpression of the Notch intracellular domain (NICD) decreased the expression of p53, p21^cip/waf, and cleaved caspase-3 in DNER-silenced cells. Moreover, NICD expression fully reverted the cell viability reduction, arrest in the G₁ phase, and elevated apoptosis caused by DNER silencing, thereby suggesting activation of Notch signaling by DNER. Expression of a membrane-unbound mutant of mDNER also decreased cell viability and induced apoptosis. On the other hand, TGF-β signals were found to be involved in DNER expression in both adherent and spheroid-cultured cells. DNER could therefore be a link connecting TGF-β signaling to Notch signaling. Taken together, DNER regulates cell proliferation, survival, and invasive capacity of the gastric cancer cells through the activation of Notch signaling, which may facilitate tumor progression into an advanced stage. This study provides evidences suggesting that DNER could be a potential prognostic marker, a therapeutic target, and a drug candidate in the form of a cell-free mutant.

The Role of STATs in Ovarian Cancer: Exploring Their Potential for Therapy

Ovarian cancer (OvCa) is a deadly gynecologic malignancy that presents many clinical challenges due to late-stage diagnoses and the development of acquired resistance to standard-of-care treatment protocols. There is an increasing body of evidence suggesting that STATs may play a critical role in OvCa progression, resistance, and disease recurrence, and thus we sought to compile a comprehensive review to summarize the current state of knowledge on the topic. We have examined peer reviewed literature to delineate the role of STATs in both cancer cells and cells within the tumor microenvironment. In addition to summarizing the current knowledge of STAT biology in OvCa, we have also examined the capacity of small molecule inhibitor development to target specific STATs and progress toward clinical applications. From our research, the best studied and targeted factors are STAT3 and STAT5, which has resulted in the development of several inhibitors that are under current evaluation in clinical trials. There remain gaps in understanding the role of STAT1, STAT2, STAT4, and STAT6, due to limited reports in the current literature; as such, further studies to establish their implications in OvCa are necessitated. Moreover, due to the deficiency in our understanding of these STATs, selective inhibitors also remain elusive, and therefore present opportunities for discovery.

Epigenetic programing of cancer stemness by transcription factors-non-coding RNAs interactions

Cancer 'stemness' is fundamental to cancer existence. It defines the ability of cancer cells to indefinitely perpetuate as well as differentiate. Cancer stem cell populations within a growing tumor also help evade the inhibitory effects of chemo- as well as radiation-therapies, in addition to playing an important role in cancer metastases. NF-κB and STAT-3 are representative transcription factors (TFs) that have long been associated with cancer stemness, thus presenting as attractive targets for cancer therapy. The growing interest in non-coding RNAs (ncRNAs) in the recent years has provided further insight into the mechanisms by which TFs influence cancer stem cell characteristics. There is evidence for a direct regulation of TFs by ncRNAs, such as, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) as well as circular RNAs (circRNAs), and vice versa. Additionally, the TF-ncRNAs regulations are often indirect, involving ncRNA-target genes or the sponging of other ncRNA species by individual ncRNAs. The information is rapidly evolving and this review provides a comprehensive review of TF-ncRNAs interactions with implications on cancer stemness and in response to therapies. Such knowledge will help uncover the many levels of tight regulations that control cancer stemness, providing novel opportunities and targets for therapy in the process.

STAT3 inhibitor BBI608 reduces patient-specific primary cell viability of cervical and endometrial cancer at a clinical-relevant concentration

PURPOSE

Aberrant activation of STAT3 signal pathway promotes tumor progression in many solid tumor types, including cervical cancer and endometrial cancer. BBI608, the STAT3 inhibitor had been reported in previous studies for restraining cancer stem cells. However, whether BBI608 is available for inhibiting the proliferation of cervical cancer or endometrial cancer remains poorly understood. This study investigated the anti-tumor effect and molecular mechanism of BBI608 on the patient-specific primary cells (PSPC) generated from cervical and endometrial cancer in vitro.

METHODS

PSPCs were obtained from four patients via biopsy. The cell viability was analyzed by the CCK8 assay. The PSPCs were treated with various concentrations of BBI608 or/and paclitaxel; and then, western blot was applied to investigate the expression of phosphorylated STAT3 (pSTAT3).

RESULTS

The PSPCs cell viability was reduced after treated with BBI608 at a lower concentration. Western blot results showed a reduction trend of pSTAT3 after PSPCs treated with BBI608. Our results demonstrated that BBI608 at the certain concentrations worked well in reducing the cell viability of PSPC from the patients who suffered from cervical cancer and endometrial cancer.

CONCLUSIONS

In this study, the patient-specific primary cell (PSPC) was used as the pre-clinical model for investigating the efficiency of BBI608 in reducing cancer cells viability. BBI608, at a clinical-relevant concentration, had valid efficiency in PSPCs from the patients. The dose of drugs treatment and the measured results were more valuable for further guiding clinical trials.

3D Spheroid Configurations Are Possible Indictors for Evaluating the Pathophysiology of Melanoma Cell Lines

To study the molecular mechanisms responsible for inducing the spatial proliferation of malignant melanomas (MM), three-dimension (3D) spheroids were produced from several MM cell lines including SK-mel-24, MM418, A375, WM266-4, and SM2-1, and their 3D architectures and cellular metabolisms were evaluated by phase-contrast microscopy and Seahorse bio-analyzer, respectively. Several transformed horizontal configurations were observed within most of these 3D spheroids, and the degree of their deformity was increased in the order: WM266-4, SM2-1, A375, MM418, and SK-mel-24. An increased maximal respiration and a decreased glycolytic capacity were observed within the lesser deformed two MM cell lines, WM266-4 and SM2-1, as compared with the most deformed ones. Among these MM cell lines, two distinct cell lines, WM266-4 and SK-mel-24, whose 3D appearances were the closest and farthest, respectively, from being horizontally circular-shaped, were subjected to RNA sequence analyses. Bioinformatic analyses of the differentially expressed genes (DEGs) identified KRAS and SOX2 as potential master regulatory genes for inducing these diverse 3D configurations between WM266-4 and SK-mel-24. The knockdown of both factors altered the morphological and functional characteristics of the SK-mel-24 cells, and in fact, their horizontal deformity was significantly reduced. A qPCR analysis indicated that the levels of several oncogenic signaling related factors, including KRAS and SOX2, PCG1α, extracellular matrixes (ECMs), and ZO1 had fluctuated among the five MM cell lines. In addition, and quite interestingly, the dabrafenib and trametinib resistant A375 (A375DT) cells formed globe shaped 3D spheroids and showed different profiles in cellular metabolism while the mRNA expression of these molecules that were tested as above were different compared with A375 cells. These current findings suggest that 3D spheroid configuration has the potential for serving as an indicator of the pathophysiological activities associated with MM.

Targeting ovarian cancer stem cells: a new way out

Ovarian cancer (OC) is the most lethal gynecological malignancy due to tumor heterogeneity, the lack of reliable early diagnosis methods and the high incidence of chemoresistant recurrent disease. Although there are developments in chemotherapies and surgical techniques to improve the overall survival of OC patients, the 5-year survival of advanced OC patients is still low. To improve the prognosis of OC patients, it is important to search for novel therapeutic approaches. Cancer stem cells (CSCs) are a subpopulation of tumor cells that participate in tumor growth, metastasis and chemoresistance. It is important to study the role of CSCs in a highly heterogeneous disease such as OC, which may be significant to a better understanding of the oncogenetic and metastatic pathways of the disease and to develop novel strategies against its progression and platinum resistance. Here, we summarized the current findings about targeting methods against ovarian cancer stem cells, including related signaling pathways, markers and drugs, to better manage OC patients using CSC-based therapeutic strategies.

Current Update on Nanotechnology-Based Approaches in Ovarian Cancer Therapy

Ovarian cancer is one of the leading causes of cancer-related deaths among women. The drawbacks of conventional therapeutic strategies encourage researchers to look for alternative strategies, including nanotechnology. Nanotechnology is one of the upcoming domains of science that is rechanneled towards targeted cancer therapy and diagnosis. Nanocarriers such as dendrimers, liposomes, polymer micelles, and polymer nanoparticles present distinct surface characteristics in morphology, surface chemistry, and mode of action that help differentiate normal and malignant cells, which paves the way for target-specific drug delivery. Similarly, nanoparticles have been strategically utilized as efficacious vehicles to deliver drugs that alter the epigenetic modifications in epigenetic therapy. Some studies suggest that the use of specialized target-modified nanoparticles in siRNA-based nanotherapy prevents internalization and improves the antitumor activity of siRNA by ensuring unrestrained entry of siRNA into the tumor vasculature and efficient intracellular delivery of siRNA. Moreover, research findings highlight the significance of utilizing nanoparticles as depots for photosensitive drugs in photodynamic therapy. The applicability of nanoparticles is further extended to medical imaging. They serve as contrast agents in combination with conventional imaging modalities such as MRI, CT, and fluorescence-based imaging to produce vivid and enhanced images of tumors. Therefore, this review aims to explore and delve deeper into the advent of various nanotechnology-based therapeutic and imaging techniques that provide non-invasive and effective means to tackle ovarian cancers.

Knock down of TIMP-2 by siRNA and CRISPR/Cas9 mediates diverse cellular reprogramming of metastasis and chemosensitivity in ovarian cancer

BACKGROUND

The endogenous tissue inhibitor of metalloproteinase-2 (TIMP-2), through its homeostatic action on certain metalloproteinases, plays a vital role in remodelling extracellular matrix (ECM) to facilitate cancer progression. This study investigated the role of TIMP-2 in an ovarian cancer cell line in which the expression of TIMP-2 was reduced by either siRNA or CRISPR/Cas9.

METHODS

OVCAR5 cells were transiently and stably transfected with either single or pooled TIMP-2 siRNAs (T2-KD cells) or by CRISPR/Cas9 under the influence of two distinct guide RNAs (gRNA1 and gRNA2 cell lines). The expression of different genes was analysed at the mRNA level by quantitative real time PCR (qRT-PCR) and at the protein level by immunofluorescence (IF) and western blot. Proliferation of cells was investigated by 5-Ethynyl-2'-deoxyuridine (EdU) assay or staining with Ki67. Cell migration/invasion was determined by xCELLigence. Cell growth in vitro was determined by 3D spheroid cultures and in vivo by a mouse xenograft model.

RESULTS

Approximately 70-90% knock down of TIMP-2 expression were confirmed in T2-KD, gRNA1 and gRNA2 OVCAR5 ovarian cancer cells at the protein level. T2-KD, gRNA1 and gRNA2 cells exhibited a significant downregulation of MMP-2 expression, but concurrently a significant upregulation in the expression of membrane bound MMP-14 compared to control and parental cells. Enhanced proliferation and invasion were exhibited in all TIMP-2 knocked down cells but differences in sensitivity to paclitaxel (PTX) treatment were observed, with T2-KD cells and gRNA2 cell line being sensitive, while the gRNA1 cell line was resistant to PTX treatment. In addition, significant differences in the growth of gRNA1 and gRNA2 cell lines were observed in in vitro 3D cultures as well as in an in vivo mouse xenograft model.

CONCLUSIONS

Our results suggest that the inhibition of TIMP-2 by siRNA and CRISPR/Cas-9 modulate the expression of MMP-2 and MMP-14 and reprogram ovarian cancer cells to facilitate proliferation and invasion. Distinct disparities in in vitro chemosensitivity and growth in 3D culture, and differences in tumour burden and invasion to proximal organs in a mouse model imply that selective suppression of TIMP-2 expression by siRNA or CRISPR/Cas-9 alters important aspects of metastasis and chemosensitivity in ovarian cancer.

Inside the stemness engine: Mechanistic links between deregulated transcription factors and stemness in cancer

Cell identity is largely determined by its transcriptional profile. In tumour, deregulation of transcription factor expression and/or activity enables cancer cell to acquire a stem-like state characterised by capacity to self-renew, differentiate and form tumours in vivo. These stem-like cancer cells are highly metastatic and therapy resistant, thus warranting a more complete understanding of the molecular mechanisms downstream of the transcription factors that mediate the establishment of stemness state. Here, we review recent research findings that provide a mechanistic link between the commonly deregulated transcription factors and stemness in cancer. In particular, we describe the role of master transcription factors (SOX, OCT4, NANOG, KLF, BRACHYURY, SALL, HOX, FOX and RUNX), signalling-regulated transcription factors (SMAD, β-catenin, YAP, TAZ, AP-1, NOTCH, STAT, GLI, ETS and NF-κB) and unclassified transcription factors (c-MYC, HIF, EMT transcription factors and P53) across diverse tumour types, thereby yielding a comprehensive overview identifying shared downstream targets, highlighting unique mechanisms and discussing complexities.

Trimethylamine N-oxide promotes demyelination in spontaneous hypertension rats through enhancing pyroptosis of oligodendrocytes

Background

Hypertension is a leading risk factor for cerebral small vessel disease (CSVD), a brain microvessels dysfunction accompanied by white matter lesions (WML). Trimethylamine N-oxide (TMAO), a metabolite of intestinal flora, is correlated with cardiovascular and aging diseases. Here, we explored the effect of TMAO on the demyelination of WML.

Methods

Spontaneous hypertension rats (SHRs) and primary oligodendrocytes were used to explore the effect of TMAO on demyelination in vivo and in vitro. T2-weighted magnetic resonance imaging (MRI) was applied to characterize the white matter hyperintensities (WMH) in rats. TMAO level was evaluated using LC-MS/MS assay. The histopathological changes of corpus callosum were measured by hematoxylin-eosin and luxol fast blue staining. And the related markers were detected by IHC, IF and western blot assay. Mito Tracker Red probe, DCFH-DA assay, flow cytometry based on JC-1 staining and Annexin V-FITC/PI double staining were conducted to evaluate the mitochondrial function, intracellular ROS levels and cell apoptosis.

Results

SHRs exhibited stronger WMH signals and a higher TMAO level than age-matched normotensive Wistar-kyoto rats (WKY). The corpus callosum region of SHR showed decreased volumes and enhanced demyelination when treated with TMAO. Furthermore, TMAO significantly elevated ROS production and induced NLRP3 inflammasome and impairment of mitochondrial function of oligodendrocytes. More importantly, TMAO enhanced the pyroptosis-related inflammatory death of oligodendrocytes.

Conclusion

TMAO could cross the blood-brain barrier (BBB) and promote oligodendrocytes pyroptosis via ROS/NLRP3 inflammasome signaling and mitochondrial dysfunction to promote demyelination, revealing a new diagnostic marker for WML under hypertension.

Advance in bone destruction participated by JAK/STAT in rheumatoid arthritis and therapeutic effect of JAK/STAT inhibitors

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic joint inflammation and bone erosion. The bones in the human body are constantly undergoing bone remodeling throughout their lives, which is the process of bone resorption by osteoclasts to damaged bone tissue and new bone formation by osteoblasts. Osteoblasts (OBs) are the main functional cells in bone formation, responsible for the synthesis, secretion and mineralization of the bone matrix. On the contrary, osteoclasts (OCs) mediate bone breakdown during natural bone turnover, but excessive breakdown occurs in RA. Under the condition of RA inflammation, many molecules, such as IL-1β, IL-6, TNF-α, IL-17 and hypoxia-inducible factor-1α (HIF-1α) are produced that could mediate bone loss. Studies have shown that cytokines mainly promote the formation of OCs and play a role in bone resorption by stimulating OBs to express receptor activator of NF-κB ligand (RANKL). JAK/STAT plays a crucial role in the process of bone destruction. And JAK/STAT pathway mediates the RANKL/receptor activator of NF-κB (RANK)/osteoprotegerin (OPG) axis. Tofacitinib, Baricitinib, Peficitinib and Filgotinib are now being used in patients with moderate to severe RA, as well as in patients with RA who have an inadequate response to methotrexate therapy and bone destruction. Currently, Tofacitiniband Baritinib areapprovedfor thetreatmentof moderate-to-severely active RA. JAK inhibitors have been reported to have better efficacy and lower adverse effects compared with methotrexate and adalimumab. In addition, two JAK inhibitors are currently in development: the JAK1 selective Upadacitinib, and the JAK3 selective inhibitor Decernotinib. In addition to the above JAK inhibitors, some small molecular compounds inhibit bone destruction by inhibiting the Phosphorylation of STAT3. In this paper, the research progress of bone destruction participated by JAK/ STAT in rheumatoid arthritis and therapeutic effect of JAK/STAT inhibitors were reviewed.

ROS and miRNA Dysregulation in Ovarian Cancer Development, Angiogenesis and Therapeutic Resistance

The diverse repertoires of cellular mechanisms that progress certain cancer types are being uncovered by recent research and leading to more effective treatment options. Ovarian cancer (OC) is among the most difficult cancers to treat. OC has limited treatment options, especially for patients diagnosed with late-stage OC. The dysregulation of miRNAs in OC plays a significant role in tumorigenesis through the alteration of a multitude of molecular processes. The development of OC can also be due to the utilization of endogenously derived reactive oxygen species (ROS) by activating signaling pathways such as PI3K/AKT and MAPK. Both miRNAs and ROS are involved in regulating OC angiogenesis through mediating multiple angiogenic factors such as hypoxia-induced factor (HIF-1) and vascular endothelial growth factor (VEGF). The NAPDH oxidase subunit NOX4 plays an important role in inducing endogenous ROS production in OC. This review will discuss several important miRNAs, NOX4, and ROS, which contribute to therapeutic resistance in OC, highlighting the effective therapeutic potential of OC through these mechanisms.

Family with sequence similarity 46 member a confers chemo-resistance to ovarian carcinoma via TGF-β/Smad2 signaling

Ovarian cancer is the most lethal malignancy with depressive 5-year survival rate, mainly due to patients with advanced stages experience tumor recurrence and resistance to the current chemotherapeutic agents. Thus, exploring the underlying molecular mechanisms involved in chemo-resistance is crucial for management of treatment to improve therapeutic outcomes. In the current study, we found overexpression of FAM46A in ovarian cancer patients demonstrated an aggressive phenotype and poor outcome. Furthermore, FAM46A overexpression in ovarian cancer cells induces higher CDDP resistance. However, inhibition of FAM46A sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. Mechanically, upregulation of FAM46A activated transforming growth factor-β (TGF-β)/Smad signaling and upregulated the levels of nuclear Smad2. Taken together, our results highlight the important oncogenic role of FAM46A in ovarian cancer progression and might provide a potential clinical target for patients with chemo resistant ovarian cancer.

Metastatic Voyage of Ovarian Cancer Cells in Ascites with the Assistance of Various Cellular Components

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-β can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.

Wnt antagonist as therapeutic targets in ovarian cancer

Ovarian cancer is a fatal malignancy in women with a low survival rate that demands new therapeutic paradigms. Cancer cells acquire various exclusive alterations to proliferate, invade, metastasize, and escape cell death, acting independently of growth-inducing or growth-inhibiting signals. The nature of cellular signaling in tumorigenesis is interwoven. Wnt signaling is an evolutionarily conserved signaling cascade that has been shown to regulate ovarian cancer pathogenesis. The molecular mechanism of Wnt signaling underlying the development of ovarian cancer, drug resistance, and relapse is not completely understood. Extracellularly secreted Wnt signaling inhibitors are crucial regulators of ovarian cancer tumorigenesis and malignant properties of cancer stem cells. Wnt inhibitors arbitrated modifications affecting Wnt pathway proteins on the cell membranes, in the cytoplasm, and in the nucleus have been shown to span essential contributions in the initiation, progression, and chemoresistance of ovarian cancer. Although many extrinsic inhibitors developed targeting the downstream components of the Wnt signaling pathway, investigating the molecular mechanisms of endogenous secreted inhibitors might substantiate prognostic or therapeutic biomarkers development. Given the importance of Wnt signaling in ovarian cancer, more systematic studies combined with clinical studies are requisite to probe the precise mechanistic interactions of Wnt antagonists in ovarian cancer. This review outlines the latest progress on the Wnt antagonists and ovarian cancer-specific regulators such as micro-RNAs, small molecules, and drugs regulating these Wnt antagonists in ovarian tumourigenesis.

Principles of dormancy evident in high-grade serous ovarian cancer

In cancer, dormancy refers to a clinical state in which microscopic residual disease becomes non-proliferative and is largely refractory to chemotherapy. Dormancy was first described in breast cancer where disease can remain undetected for decades, ultimately leading to relapse and clinical presentation of the original malignancy. A long latency period can be explained by withdrawal from cell proliferation (cellular dormancy), or a balance between proliferation and cell death that retains low levels of residual disease (tumor mass dormancy). Research into cellular dormancy has revealed features that define this state. They include arrest of cell proliferation, altered cellular metabolism, and unique cell dependencies and interactions with the microenvironment. These characteristics can be shared by dormant cells derived from disparate primary disease sites, suggesting common features exist between them.

High-grade serous ovarian cancer (HGSOC) disseminates to locations throughout the abdominal cavity by means of cellular aggregates called spheroids. These growth-arrested and therapy-resistant cells are a strong contributor to disease relapse. In this review, we discuss the similarities and differences between ovarian cancer cells in spheroids and dormant properties reported for other cancer disease sites. This reveals that elements of dormancy, such as cell cycle control mechanisms and changes to metabolism, may be similar across most forms of cellular dormancy. However, HGSOC-specific aspects of spheroid biology, including the extracellular matrix organization and microenvironment, are obligatorily disease site specific. Collectively, our critical review of current literature highlights places where HGSOC cell dormancy may offer a more tractable experimental approach to understand broad principles of cellular dormancy in cancer.

Disulfiram Transcends ALDH Inhibitory Activity When Targeting Ovarian Cancer Tumor-Initiating Cells

Epithelial ovarian cancer (EOC) is a global health burden and remains the fifth leading cause of cancer related death in women worldwide with the poorest five-year survival rate of the gynecological malignancies. EOC recurrence is considered to be driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs). We previously showed that disulfiram, an ALDH inhibitor, effectively targeted TICs compared to adherent EOC cells in terms of viability, spheroid formation, oxidative stress and also prevented relapse in an in vivo model of EOC. In this study we sought to determine whether specific targeting of ALDH isoenzyme ALDH1A1 would provide similar benefit to broader pathway inhibition by disulfiram. NCT-505 and NCT-506 are isoenzyme-specific ALDH1A1 inhibitors whose activity was compared to the effects of disulfiram. Following treatment with both the NCTs and disulfiram, the viability of TICs versus adherent cells, sphere formation, and cell death in our in vitro relapse model were measured and compared in EOC cell lines. We found that disulfiram decreased the viability of TICs significantly more effectively versus adherent cells, while no consistent trend was observed when the cells were treated with the NCTs. Disulfiram also affected the expression of proteins associated with NFκB signaling. Comparison of disulfiram to the direct targeting of ALDH1A1 with the NCTs suggests that the broader cellular effects of disulfiram are more suitable as a therapeutic to eradicate TICs from tumors and prevent EOC relapse. In addition to providing insight into a fitting treatment for TICs, the comparison of disulfiram to NCT-505 and -506 has increased our understanding of the mechanism of action of disulfiram. Further elucidation of the mechanism of disulfiram has the potential to reveal additional targets to treat EOC TICs and prevent disease recurrence.

Increased expression of NCAPG (Non-SMC condensing I complex subunit G) is associated with progression and poor prognosis of lung adenocarcinoma

Recently, studies have shown that the up-regulation of Non-SMC Condensin I Complex Subunit G (NCAPG) in some tumors can promote tumor progression, and its high expression has a strong correlation with the poor prognosis of patients. However, there are few studies on NCAPG in lung adenocarcinoma (LUAD). Our research is to explore the role of NCAPG in LUAD and try to reveal the possible molecular mechanism. We use public databases and tissue samples from LUAD patients to verify that NCAPG is significantly up-regulated in LUAD, and the high expression of NCAPG is related to the poor prognosis of patients. Subsequently, we found that silencing NCAPG can inhibit the proliferation and invasion of LUAD cells in vitro and the growth of subcutaneous tumors in nude mice in vivo. In order to explore the possible molecular mechanism of NCAPG's function, we found out the genes co-expressed with NCAPG through the cBioportal database, and discovered that these genes were significantly enriched in the cell cycle and other pathways through DAVID analysis, which implies the importance of NCAPG in the cell cycle. Finally, we confirmed by flow cytometry that NCAPG affects the conversion of cell cycle mitosis from G1 to S. Taken together, our research results suggest that NCAPG plays a role in the progress of LUAD. Moreover, NCAPG can be used as a potential biomarker for the diagnosis of LUAD, as well as a potential therapeutic target for patients with LUAD.

Deregulated miRNA clusters in ovarian cancer: Imperative implications in personalized medicine

Ovarian cancer (OC) is one of the most common and fatal types of gynecological cancer. OC is usually detected at the advanced stages of the disease, making it highly lethal. miRNAs are single-stranded, small non-coding RNAs with an approximate size ranging around 22 nt. Interestingly, a considerable proportion of miRNAs are organized in clusters with miRNA genes placed adjacent to one another, getting transcribed together to result in miRNA clusters (MCs). MCs comprise two or more miRNAs that follow the same orientation during transcription. Abnormal expression of the miRNA cluster has been identified as one of the key drivers in OC. MC exists both as tumor-suppressive and oncogenic clusters and has a significant role in OC pathogenesis by facilitating cancer cells to acquire various hallmarks. The present review summarizes the regulation and biological function of MCs in OC. The review also highlights the utility of abnormally expressed MCs in the clinical management of OC.

Recent Advances in Ovarian Cancer: Therapeutic Strategies, Potential Biomarkers, and Technological Improvements

Aggressive and recurrent gynecological cancers are associated with worse prognosis and a lack of effective therapeutic response. Ovarian cancer (OC) patients are often diagnosed in advanced stages, when drug resistance, angiogenesis, relapse, and metastasis impact survival outcomes. Currently, surgical debulking, radiotherapy, and/or chemotherapy remain the mainstream treatment modalities; however, patients suffer unwanted side effects and drug resistance in the absence of targeted therapies. Hence, it is urgent to decipher the complex disease biology and identify potential biomarkers, which could greatly contribute to making an early diagnosis or predicting the response to specific therapies. This review aims to critically discuss the current therapeutic strategies for OC, novel drug-delivery systems, and potential biomarkers in the context of genetics and molecular research. It emphasizes how the understanding of disease biology is related to the advancement of technology, enabling the exploration of novel biomarkers that may be able to provide more accurate diagnosis and prognosis, which would effectively translate into targeted therapies, ultimately improving patients’ overall survival and quality of life.

Downregulated Wnt2B Expression Suppresses Proliferation, Invasion, and Angiogenesis of Ovarian Cancer Cells Through Inhibiting the Wnt/β-Catenin Signaling Pathway

Ovarian cancer (OC) is known to be the most malignant gynecologic cancers. Wnt2B, a member of the Wnt family, plays a critical role in tumor development. However, the effect of Wnt2B on the occurrence and development of OC remains largely uncharacterized. In this study, immunohistochemistry assay indicated that Wnt2B was increased in our study cohort (OC). In addition, the expression of Wnt2B was positively correlated with TNM stages and metastasis of OC patients. Wnt2B markedly mediated the regulation of OC proliferation, invasion, and angiogenesis. Moreover, Wnt2B knockdown inactivated the Wnt/β-catenin signaling pathway. More importantly, the Wnt/β-catenin signaling pathway activator LiCl reversed the effect of Wnt2B knockdown on OC cell proliferation, angiogenesis, and invasion. Our data indicated that Wnt2B silencing could inhibit the proliferation, invasion, and angiogenesis of OC cells through downregulating the activity of Wnt/β-catenin pathway.

Role of JAK2/STAT3 Signaling Pathway in the Tumorigenesis, Chemotherapy Resistance, and Treatment of Solid Tumors: A Systemic Review

Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is a common signaling pathway used to transduce signals from the extracellular to the intracellular (nucleus) upon the binding of cytokines and growth factors to the extracellular domain of specific cell surface receptors. This signaling pathway is tightly regulated and has a multitude of biological functions such as cell proliferation, differentiation, and apoptosis. Besides, the regulated JAK2/STAT3 signaling plays a crucial role in embryonic development, hemopoiesis, and controlling the immune system. Conversely, aberrantly activated JAK2/STAT3 is frequently detected in varieties of tumors and involved in oncogenesis, angiogenesis, and metastasis of many cancer diseases that are usually refractory to the standard chemotherapy. However, the JAK3/STAT3 pathway recently emerged interestingly as a new site for the development of novel anti-tumor agents and becomes a promising therapeutic target in the treatment of many solid malignancies. Herein, this review aimed to provide insight into the JAK2/STAT3 pathway, in the hope to gain an understanding of its potential role in the pathogenesis, progression, chemotherapy resistance, and cancer therapy of solid tumors.

Cancer Stem Cells: An Ever-Hiding Foe

Cancer stem cells are a population of cells enable to reproduce the original phenotype of the tumor and capable to self-renewal, which is crucial for tumor proliferation, differentiation, recurrence, and metastasis, as well as chemoresistance. Therefore, the cancer stem cells (CSCs) have become one of the main targets for anticancer therapy and many ongoing clinical trials test anti-CSCs efficacy of plenty of drugs. This chapter describes CSCs starting from general description of this cell population, through CSCs markers, signaling pathways, genetic and epigenetic regulation, role of epithelial-mesenchymal transition (EMT) transition and autophagy, cooperation with microenvironment (CSCs niche), and finally role of CSCs in escaping host immunosurveillance against cancer.

A novel C-terminal heat shock protein 90 inhibitor that overcomes STAT3-Wnt-β-catenin signaling-mediated drug resistance and adverse effects

Rationale: The heat shock protein (Hsp) system plays important roles in cancer stem cell (CSC) and non-CSC populations. However, limited efficacy due to drug resistance and toxicity are obstacles to clinical use of Hsp90 inhibitors, suggesting the necessity to develop novel Hsp90 inhibitors overcoming these limitations. Methods: The underlying mechanism of resistance to Hsp90 inhibitors was investigated by colony formation assay, sphere formation assay, western blot analysis, and real-time PCR. To develop anticancer Hsp90 inhibitors that overcome the signal transducer and activator of transcription 3 (STAT3)-mediated resistance, we synthesized and screened a series of synthetic deguelin-based compounds in terms of inhibition of colony formation, migration, and viability of non-small cell lung cancer (NSCLC) cells and toxicity to normal cells. Regulation of Hsp90 by the selected compound NCT-80 [5-methoxy-N-(3-methoxy-4-(2-(pyridin-3-yl)ethoxy)phenyl)-2,2-dimethyl-2H-chromene-6-carboxamide] was investigated by immunoprecipitation, drug affinity responsive target stability assay, binding experiments using ATP-agarose beads and biotinylated drug, and docking analysis. The antitumor, antimetastatic, and anti-CSC effects of NCT-80 were examined in vitro and in vivo using various assays such as MTT, colony formation, and migration assays and flow cytometric analysis and tumor xenograft models. Results: We demonstrated a distinct mechanism in which Hsp90 inhibitors that block N-terminal ATP-binding pocket causes transcriptional upregulation of Wnt ligands through Akt- and ERK-mediated activation of STAT3, resulting in NSCLC cell survival in an autocrine or paracrine manner. In addition, NCT-80 effectively reduced viability, colony formation, migration, and CSC-like phenotypes of NSCLC cells and their sublines with acquired resistance to anticancer drugs by inducing apoptosis and inhibiting epithelial-mesenchymal transition and the growth of NSCLC patient-derived xenograft tumors without overt toxicity. With regards to mechanism, NCT-80 directly bound to the C-terminal ATP-binding pocket of Hsp90, disrupting the interaction between Hsp90 and STAT3 and degrading STAT3 protein. Moreover, NCT-80 inhibited chemotherapy- and EGFR TKI-induced programmed cell death ligand 1 expression and potentiated the antitumor effect of chemotherapy in the LLC-Luc allograft model. Conclusions: These data indicate the potential of STAT3/Wnt signaling pathway as a target to overcome resistance to Hsp90 inhibitors and NCT-80 as a novel Hsp90 inhibitor that targets both CSCs and non-CSCs in NSCLC.

Tumor-associated macrophages induced spheroid formation by CCL18-ZEB1-M-CSF feedback loop to promote transcoelomic metastasis of ovarian cancer

BACKGROUND

Ovarian cancer (OvCa)-tumor-associated macrophages (TAMs) spheroids are abundantly present within ascites of high malignant patients. This study investigated the mutual interaction of OvCa cells and TAMs in the spheroids.

METHODS

Three-dimensional coculture system and transwell coculture system were created to mimic the OvCa and TAMs in spheroids and in disassociated state. Transwell-migration assay and scratch wound healing assay were used to measure the invasive and migratory capacity. Western blot, quantitative reverse transcription-PCR and immunostaining were used to measure the mesenchymal and epithelial markers. Flow cytometry was used to assess the polarization of TAMs. Also, the differential gene expression profile of OvCa cells and OvCa cells from spheroids were tested by RNA-sequence. Finally, the ovarian mice models were constructed by intraperitoneal injection of ID8 or OvCa-TAMs spheroids.

RESULTS

Our results indicated that the formation of OvCa-TAMs spheroids was positive related to the malignancy of OvCa cells. M2-TAMs induced the epithelial-mesenchymal transition of OvCa cells by releasing chemokine (C-C motif) ligand 18 (CCL18) in the spheroids. While, CCL18 induced macrophage colony-stimulating factor (M-CSF) transcription in OvCa cells through zinc finger E-box-binding homeobox 1 (ZEB1). This study further indicated that M-CSF secreted by OvCa cells drived the polarization of M2-TAMs. Therefore, a CCL18-ZEB1-M-CSF interacting loop between OvCa cells and TAMs in the spheroids was identified. Moreover, with blocking the expression of ZEB1 in the OvCa cell, the formation of OvCa-TAMs spheroids was impeded. In the ovarian mice models, the formation of OvCa-TAMs spheroids in the ascites was promoted by overexpressing of ZEB1 in OvCa cells, which resulted in faster and earlier transcoelomic metastasis.

CONCLUSION

These findings suggested that the formation of OvCa-TAMs spheroids resulted in aggressive phenotype of OvCa cells, as a specific feedback loop CCL18-ZEB1-M-CSF in it. Inhibition of ZEB1 reduced OvCa-TAMs spheroids in the ascites, impeding the transcoelomic metastasis and improving the outcome of ovarian patients.

MicroRNAs and JAK/STAT3 signaling: A new promising therapeutic axis in blood cancers

Blood disorders include a wide spectrum of blood-associated malignancies resulting from inherited or acquired defects. The ineffectiveness of existing therapies against blood disorders arises from different reasons, one of which is drug resistance, so different types of leukemia may show different responses to treatment. Leukemia occurs for a variety of genetic and acquired reasons, leading to uncontrolled proliferation in one or more cell lines. Regarding the genetic defects, oncogene signal transducer and activator of transcription (STAT) family transcription factor, especially STAT3, play an essential role in hematological disorders onset and progress upon mutations, dysfunction, or hyperactivity. Besides, microRNAs, as biological molecules, has been shown to play a dual role in either tumorigenesis and tumor suppression in various cancers. Besides, a strong association between STAT3 and miRNA has been reported. For example, miRNAs can regulate STAT3 via targeting its upstream mediators such as IL6, IL9, and JAKs or directly binding to the STAT3 gene. On the other hand, STAT3 can regulate miRNAs. In this review study, we aimed to determine the role of either microRNAs and STAT3 along with their effect on one another's activity and function in hematological malignancies.

The impact of STAT3 and phospho-STAT3 expression on the prognosis and clinicopathology of ovarian cancer: a systematic review and meta-analysis

Purpose

STAT3 and p-STAT3 are often overexpressed in various human tumours and participate in cancer development and progression. However, whether STAT3/p-STAT3 expression is associated with clinicopathologic characteristics and has prognostic significance for people suffering from ovarian cancer remains controversial. We conducted a systematic review and meta-analyses to clarify the associations between STAT3/p-STAT3 expression and clinicopathologic characteristics and prognostic factors of ovarian cancer.

Methods

A systematic electronic search in the PubMed, Embase, CNKI, and Wanfang databases was conducted to identify relevant articles published before 3 April 2021. All statistical analyses were performed using Stata 15.1.

Results

We included 16 eligible studies incorporating 1747 ovarian cancer patients. The expression of STAT3/p-STAT3 was upregulated in ovarian cancer samples versus normal ovarian tissue, benign tumours and borderline tumours (OR = 10.14, p < 0.00001; OR = 9.08, P < 0.00001; OR = 4.01, p < 0.00001, respectively). STAT3/p-STAT3 overexpression was significantly correlated with FIGO stage (I-II vs. III-IV) (OR = 0.36, p < 0.00001), tumour grade (G1 + G2 vs. G3) (OR = 0.55; p = 0.001) and lymph node metastasis (yes vs. no) (OR = 3.39; p < 0.00001). High STAT3/p-STAT3 expression was correlated with poorer prognosis of ovarian cancer patients for both overall survival (OS) (HR = 1.67, p < 0.00001) and progression-free survival (PFS) (HR = 1.40, p = 0.007).

Conclusion

The present meta-analysis indicated that high STAT3/p-STAT3 expression is likely predictive of an unfavourable prognosis in ovarian cancer patients. Nonetheless, prospective trials are required to confirm these associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00918-6.

Characterization of the Potential Role of NTPCR in Epithelial Ovarian Cancer by Integrating Transcriptomic and Metabolomic Analysis

Background

Epithelial ovarian carcinoma (EOC) is a malignant tumor with high motility in women. Our previous study found that dysregulated nucleoside-triphosphatase cancer-related (NTPCR) was associated with the prognosis of EOC patients, and thus, this present study attempted to explore the potential roles of NTPCR in disease progression.

Methods

Expressed level of NTPCR was investigated in EOC tissues by RT-qPCR and Western blot analysis. NTPCR shRNA and overexpression vector were generated and transfected into OVCAR-3 or SKOV3 cells to detect the effect of NTPCR on cell proliferation, cell cycle, cell migration, and invasion. Transcriptomic sequencing and metabolite profiling analysis were performed in shNTPCR groups to identify transcriptome or metabolite alteration that might contribute to EOC. Finally, we searched the overlapped signaling pathways correlated with differential metabolites and differentially expressed genes (DEGs) by integrating analysis.

Results

Comparing para-cancerous tissues, we found that NTPCR is highly expressed in cancer tissues (p < 0.05). Overexpression of NTPCR inhibited cell proliferation, migration, and invasion and reduced the proportion of S- and G2/M-phase cells, while downregulation of NTPCR showed the opposite results. RNA sequencing analysis demonstrated cohorts of DEGs were identified in shNTPCR samples. Protein–protein interaction networks were constructed for DEGs. STAT1 (degree = 43) and OAS2 (degree = 36) were identified as hub genes in the network. Several miRNAs together with target genes were predicted to be crucial genes related to disease progression, including hsa-miR-124-3p, hsa-miR-30a-5p, hsa-miR-146a-5, EP300, GATA2, and STAT3. We also screened the differential metabolites from shNTPCR samples, including 22 upregulated and 22 downregulated metabolites. By integrating transcriptomics and metabolomics analysis, eight overlapped pathways were correlated with these DEGs and differential metabolites, such as primary bile acid biosynthesis, protein digestion, and absorption, pentose, and glucuronate interconversions.

Conclusion

NTPCR might serve as a tumor suppressor in EOC progression. Our results demonstrated that DEGs and differential metabolites were mainly related to several signaling pathways, which might be a crucial role in the progression of NTPCR regulation of EOC.

The Emerging Role of Non-coding RNAs in Drug Resistance of Ovarian Cancer

Ovarian cancer is one of the most common gynecological malignancies with highest mortality rate among all gynecological malignant tumors. Advanced ovarian cancer patients can obtain a survival benefit from chemotherapy, including platinum drugs and paclitaxel. In more recent years, the administration of poly-ADP ribose polymerase inhibitor to patients with BRCA mutations has significantly improved the progression-free survival of ovarian cancer patients. Nevertheless, primary drug resistance or the acquisition of drug resistance eventually leads to treatment failure and poor outcomes for ovarian cancer patients. The mechanism underlying drug resistance in ovarian cancer is complex and has not been fully elucidated. Interestingly, different non-coding RNAs (ncRNAs), such as circular RNAs, long non-coding RNAs and microRNAs, play a critical role in the development of ovarian cancer. Accumulating evidence has indicated that ncRNAs have important regulatory roles in ovarian cancer resistance to chemotherapy reagents and targeted therapy drugs. In this review, we systematically highlight the emerging roles and the regulatory mechanisms by which ncRNAs affect ovarian cancer chemoresistance. Additionally, we suggest that ncRNAs can be considered as potential diagnostic and prognostic biomarkers as well as novel therapeutic targets for ovarian cancer.

Puerarin induces platinum-resistant epithelial ovarian cancer cell apoptosis by targeting SIRT1

OBJECTIVE

Previous investigations indicated the anticancer activity of puerarin. The current study aimed to evaluate the effect and molecular mechanisms of puerarin in chemotherapy-resistant ovarian cancer cells.

METHODS

We examined the effects of puerarin in platinum-resistant epithelial ovarian cancer cells in vitro and in vivo. We also analyzed the molecular mechanism underlying Wnt/β-catenin inhibition and sirtuin 1 (SIRT1) regulation following puerarin treatment.

RESULTS

Our study demonstrated that puerarin effectively inhibited cell growth in vitro and in vivo by increasing apoptosis in ovarian cancer cells. More importantly, puerarin sensitized cisplatin-resistant ovarian cancer cells to chemotherapy. Puerarin treatment decreased SIRT1 expression, which attenuated the nuclear accumulation of β-catenin to inhibit Wnt/β-catenin signaling. In addition, SIRT1 overexpression diminished the effects of puerarin treatment on cisplatin-resistant ovarian cancer cells. Further analysis supported SIRT1/β-catenin expression as a candidate biomarker for the disease progression of epithelial ovarian cancer.

CONCLUSIONS

Puerarin increased the apoptosis of platinum-resistant ovarian cancer cells. The mechanism is partly related to the downregulation of SIRT1 and subsequent inhibition of Wnt/β-catenin signaling.

MiR-337 suppresses pancreatic cancer development via STAT3/Wnt/β-catenin axis

MiRNA is an important regulator of tumorigenesis and tumor progression. MiR-337 expression was increased in pancreatic cancer tissues and it was associated with patients' survival. This study aimed to explore the influence and the potential working mechanism of miR-337 on the malignant behaviors of pancreatic cancer cells. MiR-337 expression was detected by qRT-PCR. The expression levels of STAT3, epithelial-mesenchymal transition-related genes and Wnt/β-Catenin pathway genes were evaluated by qRT-PCR and western blot. Cell counting kit -8 and colony formation assays were conducted to examine the proliferation of AsPC-1 and SW1990 cells. Wound healing and transwell assays were performed to determine the migration and invasion of AsPC-1 and SW1990 cells. The predicted target gene of miR-337 was verified by luciferase reporter assay. The expression of miR-337 was decreased and STAT3 expression was increased in pancreatic cancer tissues as well as tumor cells. Overexpression of miR-337 suppressed proliferation, invasion and migration of AsPC-1 and SW1990 cells. MiR-337 targeted 3'UTR of STAT3 and inhibited STAT3 expression. In addition, exogenous STAT3 partially restored the inhibitory role of miR-337 on proliferation, invasion and migration of AsPC-1 and SW1990 cells. Moreover, miR-337 impeded the expression of Wnt/β-catenin pathway-related genes. Through the saving experiment, we found that the inhibitory effect of miR-337 on AsPC-1 and SW1990 cells was abolished by the addition of LiCl. These outcomes expounded that miR-337 inactivated the Wnt/β-catenin pathway to suppress the malignant behaviors of pancreatic cancer cells through targeting STAT3. This study may provide a novel biomarker for diagnosis and a new therapeutic target for pancreatic cancer treatment.

Transcending toward Advanced 3D-Cell Culture Modalities: A Review about an Emerging Paradigm in Translational Oncology

Cancer is a disorder characterized by an uncontrollable overgrowth and a fast-moving spread of cells from a localized tissue to multiple organs of the body, reaching a metastatic state. Throughout years, complexity of cancer progression and invasion, high prevalence and incidence, as well as the high rise in treatment failure cases leading to a poor patient prognosis accounted for continuous experimental investigations on animals and cellular models, mainly with 2D- and 3D-cell culture. Nowadays, these research models are considered a main asset to reflect the physiological events in many cancer types in terms of cellular characteristics and features, replication and metastatic mechanisms, metabolic pathways, biomarkers expression, and chemotherapeutic agent resistance. In practice, based on research perspective and hypothesis, scientists aim to choose the best model to approach their understanding and to prove their hypothesis. Recently, 3D-cell models are seen to be highly incorporated as a crucial tool for reflecting the true cancer cell microenvironment in pharmacokinetic and pharmacodynamics studies, in addition to the intensity of anticancer drug response in pharmacogenomics trials. Hence, in this review, we shed light on the unique characteristics of 3D cells favoring its promising usage through a comparative approach with other research models, specifically 2D-cell culture. Plus, we will discuss the importance of 3D models as a direct reflector of the intrinsic cancer cell environment with the newest multiple methods and types available for 3D-cells implementation.

Stat3 loss in mesenchymal progenitors causes Job syndrome-like skeletal defects by reducing Wnt/β-catenin signaling

Job syndrome is a rare genetic disorder caused by STAT3 mutations and primarily characterized by immune dysfunction along with comorbid skeleton developmental abnormalities including osteopenia, recurrent fracture of long bones, and scoliosis. So far, there is no definitive cure for the skeletal defects in Job syndrome, and treatments are limited to management of clinical symptoms only. Here, we have investigated the molecular mechanism whereby Stat3 regulates skeletal development and osteoblast differentiation. We showed that removing Stat3 function in the developing limb mesenchyme or osteoprogenitor cells in mice resulted in shortened and bow limbs with multiple fractures in long bones that resembled the skeleton symptoms in the Job Syndrome. However, Stat3 loss did not alter chondrocyte differentiation and hypertrophy in embryonic development, while osteoblast differentiation was severely reduced. Genome-wide transcriptome analyses as well as biochemical and histological studies showed that Stat3 loss resulted in down-regulation of Wnt/β-catenin signaling. Restoration of Wnt/β-catenin signaling by injecting BIO, a small molecule inhibitor of GSK3, or crossing with a Lrp5 gain of function (GOF) allele, rescued the bone reduction phenotypes due to Stat3 loss to a great extent. These studies uncover the essential functions of Stat3 in maintaining Wnt/β-catenin signaling in early mesenchymal or osteoprogenitor cells and provide evidence that bone defects in the Job Syndrome are likely caused by Wnt/β-catenin signaling reduction due to reduced STAT3 activities in bone development. Enhancing Wnt/β-catenin signaling could be a therapeutic approach to reduce bone symptoms of Job syndrome patients.

miRNA signaling networks in cancer stem cells

Cancer stem cells (CSCs) are a small cell subpopulation in many cancer types and are involved in various processes of tumor progression, such as initiation, metastasis and recurrence. The distinguished features of CSCs include a variety of biological properties, including self-renewal, multidifferentiation, stemness marker expression, and resistance to chemotherapy and radiotherapy. Despite their great potential of clinical importance, the CSC signaling pathways are not well understood at the molecular level. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs that play an important role in the regulation of several cellular, physiological, and developmental processes. Aberrant miRNA expression is associated with many human diseases, including cancer. miRNAs have been implicated in the regulation of CSC properties; therefore, a better understanding of miRNA-induced modulation of CSC gene expression could aid in the identification of promising biomarkers and therapeutic targets. In the present review, we summarize the major findings of the impacts of miRNAs on CSC signaling networks; we then discuss the recent advances that have improved our understanding of CSC regulation by miRNA-mediated signaling networks and that may lead to the development of miRNA therapeutics specifically targeting CSCs.

Isoorientin inhibits epithelial-to-mesenchymal properties and cancer stem-cell-like features in oral squamous cell carcinoma by blocking Wnt/β-catenin/STAT3 axis

Oral squamous cell carcinoma (OSCC) is among the most prevalent cancers of the head and neck. This study revealed that isoorientin attenuates OSCC cell stemness and epithelial-mesenchymal transition potential through the inhibition of JAK/signal transducer and activator of transcription 3 (STAT3) and Wnt/β-catenin signaling in cell lines. Our findings indicated that isoorientin is a potential inhibitor of β-catenin/STAT3 in vitro and in vivo. We analyzed possible synergism between isoorientin and cisplatin in OSCC. A sulforhodamine B assay, colony formation assay, tumorsphere-formation assay, and Wnt reporter activity assay were used for determining cell invasion, cell migration, drug cytotoxicity, and cell viability with potential molecular mechanisms in vitro. Isoorientin reduced the expression of p-STAT3, β-catenin, and p-GSK3 as well as downstream effectors TCF1/TCF7 and LEF1 and significantly reduced β-catenin colocalization in the nucleus. Isoorientin markedly strengthened the cytotoxic effects of cisplatin against SAS and SCC-25. Therefore, combining isoorientin and cisplatin treatments can potentially improve the anticancer effect of cisplatin. Isoorientin inhibited the tumorigenicity and growth of OSCC through the abrogation of Wnt/β-catenin/STAT3 signaling in vivo. Thus, isoorientin disrupted the β-catenin signaling pathway through the inactivation of STAT3 signaling. In conclusion, targeting OSCC-SC-mediated stemness with isoorientin to eradicate OSCC-SCs may be an effective strategy for preventing relapse and metastasis of OSCC and providing long-term survival benefits.