Aberrant activation of hedgehog signaling pathway in ovarian cancers: effect on prognosis, cell invasion and differentiation

Aberrant angiogenic signaling pathways: Accomplices in ovarian cancer progression and treatment

Ovarian cancer is one of the most common malignant tumors in women, and treatment options are limited. Despite efforts to adjust cancer treatment models and develop new methods, including tumor microenvironment (TME) therapy, more theoretical support is needed. Increasing attention is being given to antiangiogenic measures for TME treatment. Another important concept in ovarian cancer TME is angiogenesis, where tumor cells obtain nutrients and oxygen from surrounding tissues through blood vessels to support further expansion and metastasis. Many neovascularization signaling pathways become imbalanced and hyperactive during this process. Inhibiting these abnormal pathways can yield ideal therapeutic effects in patients, even by reversing drug resistance. However, these deep TME signaling pathways often exhibit crosstalk and correlation. Understanding these interactions may be an important strategy for further treating ovarian cancer. This review summarizes the latest progress and therapeutic strategies for these angiogenic signaling pathways in ovarian cancer.

MYCN in human development and diseases

Somatic mutations in MYCN have been identified across various tumors, playing pivotal roles in tumorigenesis, tumor progression, and unfavorable prognoses. Despite its established notoriety as an oncogenic driver, there is a growing interest in exploring the involvement of MYCN in human development. While MYCN variants have traditionally been associated with Feingold syndrome type 1, recent discoveries highlight gain-of-function variants, specifically p.(Thr58Met) and p.(Pro60Leu), as the cause for megalencephaly-polydactyly syndrome. The elucidation of cellular and murine analytical data from both loss-of-function (Feingold syndrome model) and gain-of-function models (megalencephaly-polydactyly syndrome model) is significantly contributing to a comprehensive understanding of the physiological role of MYCN in human development and pathogenesis. This review discusses the MYCN's functional implications for human development by reviewing the clinical characteristics of these distinct syndromes, Feingold syndrome, and megalencephaly-polydactyly syndrome, providing valuable insights into the understanding of pathophysiological backgrounds of other syndromes associated with the MYCN pathway and the overall comprehension of MYCN's role in human development.

Research progress on arsenic, arsenic-containing medicinal materials, and arsenic-containing preparations: clinical application, pharmacological effects, and toxicity

Introduction: The toxicity of arsenic is widely recognized globally, mainly harming human health by polluting water, soil, and food. However, its formulations can also be used for the clinical treatment of diseases such as leukemia and tumors. Arsenic has been used as a drug in China for over 2,400 years, with examples such as the arsenic-containing drug realgar mentioned in Shennong's Herbal Classic. We have reviewed references on arsenic over the past thirty years and found that research has mainly focused on clinical, pharmacological, and toxicological aspects. Results and Discussion: The finding showed that in clinical practice, arsenic trioxide is mainly used in combination with all-trans retinoic acid (ATRA) at a dose of 10 mg/d for the treatment of acute promyelocytic leukemia (APL); realgar can be used to treat acute promyelocytic leukemia, myelodysplastic syndrome, and lymphoma. In terms of pharmacology, arsenic mainly exerts anti-tumor effects. The dosage range of the action is 0.01-80 μmol/L, and the concentration of arsenic in most studies does not exceed 20 μmol/L. The pharmacological effects of realgar include antiviral activity, inhibition of overactivated lactate dehydrogenase, and resistance to malaria parasites. In terms of toxicity, arsenic is toxic to multiple systems in a dose-dependent manner. For example, 5 μmol/L sodium arsenite can induce liver oxidative damage and promote the expression of pro-inflammatory factors, and 15 μmol/L sodium arsenite induces myocardial injury; when the concentration is higher, it is more likely to cause toxic damage.

A clinicopathological exploration of Hedgehog signaling: implications in oral carcinogenesis

INTRODUCTION

Hedgehog Signaling, a basic cancer stem cell pathway, plays a major role during the embryonic development, is known to play a quiescent role in adults. However, aberrant activation of Hedgehog signaling in adults is known to play a role in cancer development. Hence, the aim of the study was to identify the role of Hedgehog signaling pathway in the Oral cancers.

MATERIALS AND METHODS

The expression of Hedgehog signaling pathway was evaluated in 124 patients through the quantitative real-time PCR. The association between the gene expression and clinico-pathological parameters were analyzed using the Pearson chi-square test and survival analysis was carried out using Kaplan-Meier analysis.

RESULTS

SHH and GLI1 was found to be significantly associated with the Lymph Node Status and SUFU was significantly associated with the Age. SMO and SUFU were found to have a worse prognosis in oral cancer patients. According to our findings, IHH plays a critical role in the activation of the HH signaling pathway in oral cancer.

CONCLUSION

These findings back up the use of the Hedgehog signaling pathway as a biomarker for early disease prediction in oral cancer, as well as its role in tumor aggressiveness and invasiveness.

Epigenetic control of cell signalling in cancer stem cells

The self-renewing cancer stem cells (CSCs) represent one of the distinct cell populations occurring in a tumour that can differentiate into multiple lineages. This group of sparsely abundant cells play a vital role in tumour survival and resistance to different treatments during cancer. The lack of exclusive markers associated with CSCs makes diagnosis and prognosis in cancer patients extremely difficult. This calls for the identification of unique regulators and markers for CSCs. Various signalling pathways like the Wnt/β-catenin pathway, Hedgehog pathway, Notch pathway, and TGFβ/BMP play a major role in the regulation and maintenance of CSCs. Epigenetic regulatory mechanisms add another layer of complexity to control these signalling pathways. In this chapter, we discuss about the role of epigenetic mechanisms in regulating the cellular signalling pathways in CSCs. The epigenetic regulatory mechanisms such as DNA methylation, histone modification and microRNAs can modulate the diverse effectors of signalling pathways and consequently the growth, differentiation and tumorigenicity of CSCs. In the end, we briefly discuss the therapeutic potential of targeting these epigenetic regulators and their target genes in CSCs.

Deciphering Common Traits of Breast and Ovarian Cancer Stem Cells and Possible Therapeutic Approaches

Breast cancer (BC) and ovarian cancer (OC) are among the most common and deadly cancers affecting women worldwide. Both are complex diseases with marked heterogeneity. Despite the induction of screening programs that increase the frequency of earlier diagnosis of BC, at a stage when the cancer is more likely to respond to therapy, which does not exist for OC, more than 50% of both cancers are diagnosed at an advanced stage. Initial therapy can put the cancer into remission. However, recurrences occur frequently in both BC and OC, which are highly cancer-subtype dependent. Therapy resistance is mainly attributed to a rare subpopulation of cells, named cancer stem cells (CSC) or tumor-initiating cells, as they are capable of self-renewal, tumor initiation, and regrowth of tumor bulk. In this review, we will discuss the distinctive markers and signaling pathways that characterize CSC, their interactions with the tumor microenvironment, and the strategies they employ to evade immune surveillance. Our focus will be on identifying the common features of breast cancer stem cells (BCSC) and ovarian cancer stem cells (OCSC) and suggesting potential therapeutic approaches.

Matrix Gla Protein drives stemness and tumor initiation in ovarian cancer

Ovarian cancer (OC) displays the highest mortality among gynecological tumors, mainly due to early peritoneal dissemination, the high frequency of tumor relapse following primary debulking, and the development of chemoresistance. All these events are thought to be initiated and sustained by a subpopulation of neoplastic cells, termed ovarian cancer stem cells (OCSC), that are endowed with self-renewing and tumor-initiating properties. This implies that interfering with OCSC function should offer novel therapeutic perspectives to defeat OC progression. To this aim, a better understanding of the molecular and functional makeup of OCSC in clinically relevant model systems is essential. We have profiled the transcriptome of OCSC vs. their bulk cell counterpart from a panel of patient-derived OC cell cultures. This revealed that Matrix Gla Protein (MGP), classically known as a calcification-preventing factor in cartilage and blood vessels, is markedly enriched in OCSC. Functional assays showed that MGP confers several stemness-associated traits to OC cells, including a transcriptional reprogramming. Patient-derived organotypic cultures pointed to the peritoneal microenvironment as a major inducer of MGP expression in OC cells. Furthermore, MGP was found to be necessary and sufficient for tumor initiation in OC mouse models, by shortening tumor latency and increasing dramatically the frequency of tumor-initiating cells. Mechanistically, MGP-driven OC stemness was mediated by the stimulation of Hedgehog signaling, in particular through the induction of the Hedgehog effector GLI1, thus highlighting a novel MGP/Hedgehog pathway axis in OCSC. Finally, MGP expression was found to correlate with poor prognosis in OC patients, and was increased in tumor tissue after chemotherapy, supporting the clinical relevance of our findings. Thus, MGP is a novel driver in OCSC pathophysiology, with a major role in stemness and in tumor initiation.

Analysis of matched primary and recurrent BRCA1/2 mutation-associated tumors identifies recurrence-specific drivers

Recurrence is a major cause of death among BRCA1/2 mutation carriers with breast (BrCa) and ovarian cancers (OvCa). Herein we perform multi-omic sequencing on 67 paired primary and recurrent BrCa and OvCa from 27 BRCA1/2 mutation carriers to identify potential recurrence-specific drivers. PARP1 amplifications are identified in recurrences (False Discovery Rate q = 0.05), and PARP1 is significantly overexpressed across primary BrCa and recurrent BrCa and OvCa, independent of amplification status. RNA sequencing analysis finds two BRCA2 isoforms, BRCA2-201/Long and BRCA2-001/Short, respectively predicted to be sensitive and insensitive to nonsense-mediated decay. BRCA2-001/Short is expressed more frequently in recurrences and associated with reduced overall survival in breast cancer (87 vs. 121 months; Hazard Ratio = 2.5 [1.18-5.5]). Loss of heterozygosity (LOH) status is discordant in 25% of patient's primary and recurrent tumors, with switching between both LOH and lack of LOH found. Our study reveals multiple potential drivers of recurrent disease in BRCA1/2 mutation-associated cancer, improving our understanding of tumor evolution and suggesting potential biomarkers.

Regulation of the aryl hydrocarbon receptor in cancer and cancer stem cells of gynecological malignancies: An update on signaling pathways

Gynecological malignancies are a female type of cancers that affects the reproductive system. Cancer metastasis or recurrence mediated by cellular invasiveness occurs at advanced stages of cancer progression. Cancer Stem Cells (CSCs) enrichment in tumors leads to chemoresistance, which results in cancer mortality. Exposure to environmental pollutants such as polycyclic aromatic hydrocarbons is associated with an increased the risk of CSC enrichment in gynecological cancers. One of the important pathways that mediates the metabolism and bioactivation of these environmental chemicals is the transcription factor, aryl hydrocarbon receptor (AhR). The present review explores the molecular mechanisms regulating the crosstalk and interaction of the AhR with cancer-related signaling pathways, such as apoptosis, epithelial-mesenchymal transition, immune checkpoints, and G-protein-coupled receptors in several gynecological malignancies such as ovarian, uterine, endometrial, and cervical cancers. The review also discusses the potential of targeting the AhR pathway as a novel chemotherapy for gynecological cancers.

The Proteolytic Landscape of Ovarian Cancer: Applications in Nanomedicine

Ovarian cancer (OvCa) is one of the leading causes of mortality globally with an overall 5-year survival of 47%. The predominant subtype of OvCa is epithelial carcinoma, which can be highly aggressive. This review launches with a summary of the clinical features of OvCa, including staging and current techniques for diagnosis and therapy. Further, the important role of proteases in OvCa progression and dissemination is described. Proteases contribute to tumor angiogenesis, remodeling of extracellular matrix, migration and invasion, major processes in OvCa pathology. Multiple proteases, such as metalloproteinases, trypsin, cathepsin and others, are overexpressed in the tumor tissue. Presence of these catabolic enzymes in OvCa tissue can be exploited for improving early diagnosis and therapeutic options in advanced cases. Nanomedicine, being on the interface of molecular and cellular scales, can be designed to be activated by proteases in the OvCa microenvironment. Various types of protease-enabled nanomedicines are described and the studies that focus on their diagnostic, therapeutic and theranostic potential are reviewed.

Mesenchymal Stem/Stromal Cells May Decrease Success of Cancer Treatment by Inducing Resistance to Chemotherapy in Cancer Cells

Simple Summary

Tumours consist of different cell types and an extracellular matrix, all of which together form a complex microenvironment. The tumour microenvironment plays a critical role in various aspects of tumour development and progression. Mesenchymal stem/stromal cells (MSCs) are multipotent stem cells that have a tri-lineage differentiation capacity and are one of the key stromal cells in the tumour microenvironment. Following the interaction with cancer cells, they are transformed from naïve MSCs to tumour-associated MSCs, which substantially affect tumour growth and progression as well as the development of chemoresistance in cancer cells. The aim of this review article is to provide an overview of studies that have investigated how MSCs affect the susceptibility of cancer cells to chemotherapeutics. Their results show that MSCs protect cancer cells from chemotherapeutics by influencing several signalling pathways. This knowledge is crucial for the development of new treatment approaches that will lead to improved treatment outcomes.

Abstract

The tumour microenvironment, which is comprised of various cell types and the extracellular matrix, substantially impacts tumour initiation, progression, and metastasis. Mesenchymal stem/stromal cells (MSCs) are one of the key stromal cells in the tumour microenvironment, and their interaction with cancer cells results in the transformation of naïve MSCs to tumour-associated MSCs. The latter has an important impact on tumour growth and progression. Recently, it has been shown that they can also contribute to the development of chemoresistance in cancer cells. This review provides an overview of 42 studies published between 1 January 2001 and 1 January 2022 that examined the effect of MSCs on the susceptibility of cancer cells to chemotherapeutics. The studies showed that MSCs affect various signalling pathways in cancer cells, leading to protection against chemotherapy-induced damage. Promising results emerged from the use of inhibitors of various signalling pathways that are affected in cancer cells due to interactions with MSCs in the tumour microenvironment. These studies present a good starting point for the investigation of novel treatment approaches and demonstrate the importance of targeting the stroma in the tumour microenvironment to improve treatment outcomes.

Survivin, Sonic hedgehog, Krüppel-like factors, and p53 pathway in serous ovarian cancer: an immunohistochemical study

OBJECTIVE

Survivin was previously associated with tumor stage and grade in ovarian cancer and interfered with the tumor's drug sensitivity. In addition, Survivin expression was found to be regulated by the Sonic hedgehog (Shh) pathway, Krüppel-like factor (KLF) family proteins, and p53 pathway. The main aim of this study was to assess the prognostic values of immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a cohort of high grade ovarian serous cancers. Other aims were comparison between high- and low-grade ovarian serous cancer and between platinum-resistant and the other cases. The last aim was to assess the correlations among the immunohistochemical expression of the studied proteins.

METHODS

Retrospective cohort study to assess immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a tissue microarray of primary tumor samples among 73 women affected by high-grade ovarian serous cancer and 9 by low-grade ovarian serous cancer.

RESULTS

Klf5 and Shh cytoplasmic staining were associated to short overall survival (HR 6.38, CI.95 2.25 - 18.01, p<0.05 and 2.25, CI.95 1.19-4.23, p<0.05 respectively). In addition, cytoplasmic Klf5 staining, high Klf11 and p53 nuclear staining were associated with platinum resistance (p<0.05). Cytoplasmic Shh score was significantly correlated to the immunohistochemical expression of Klf5, Klf11, Mdm2, and Survivin.

CONCLUSIONS

Our data highlight the possible role of Klf5 and Shh as prognostic markers, meanwhile confirming the role of the KLF family proteins and p53 in ovarian cancer drug resistance. Moreover, Shh appeared to play an important role in the intracellular network of ovarian neoplasia.

Hedgehog Autoprocessing: From Structural Mechanisms to Drug Discovery

Hedgehog (Hh) signaling plays pivotal roles in embryonic development. In adults, Hh signaling is mostly turned off but its abnormal activation is involved in many types of cancer. Hh signaling is initiated by the Hh ligand, generated from the Hh precursor by a specialized autocatalytic process called Hh autoprocessing. The Hh precursor consists of an N-terminal signaling domain (HhN) and a C-terminal autoprocessing domain (HhC). During Hh autoprocessing, the precursor is cleaved between N- and C-terminal domain followed by the covalent ligation of cholesterol to the last residue of HhN, which subsequently leads to the generation of Hh ligand for Hh signaling. Hh autoprocessing is at the origin of canonical Hh signaling and precedes all downstream signaling events. Mutations in the catalytic residues in HhC can lead to congenital defects such as holoprosencephaly (HPE). The aim of this review is to provide an in-depth summary of the progresses and challenges towards an atomic level understanding of the structural mechanisms of Hh autoprocessing. We also discuss drug discovery efforts to inhibit Hh autoprocessing as a new direction in cancer therapy.

Cancer Immunoediting: Elimination, Equilibrium, and Immune Escape in Solid Tumors

Emphasizing the dynamic processes between cancer and host immune system, the initially discovered concept of cancer immunosurveillance has been replaced by the current concept of cancer immunoediting consisting of three phases: elimination, equilibrium, and escape. Solid tumors composed of both cancer and host stromal cells are an example how the three phases of cancer immunoediting functionally evolve and how tumor shaped by the host immune system gets finally resistant phenotype. The elimination, equilibrium, and escape have been described in this chapter in details, including the role of immune surveillance, cancer dormancy, disruption of the antigen-presenting machinery, tumor-infiltrating immune cells, resistance to apoptosis, as well as the function of tumor stroma, microvesicles, exosomes, and inflammation.

The Role of Smoothened-Dependent and -Independent Hedgehog Signaling Pathway in Tumorigenesis

The Hedgehog (Hh)-glioma-associated oncogene homolog (GLI) signaling pathway is highly conserved among mammals, with crucial roles in regulating embryonic development as well as in cancer initiation and progression. The GLI transcription factors (GLI1, GLI2, and GLI3) are effectors of the Hh pathway and are regulated via Smoothened (SMO)-dependent and SMO-independent mechanisms. The SMO-dependent route involves the common Hh-PTCH-SMO axis, and mutations or transcriptional and epigenetic dysregulation at these levels lead to the constitutive activation of GLI transcription factors. Conversely, the SMO-independent route involves the SMO bypass regulation of GLI transcription factors by external signaling pathways and their interacting proteins or by epigenetic and transcriptional regulation of GLI transcription factors expression. Both routes of GLI activation, when dysregulated, have been heavily implicated in tumorigenesis of many known cancers, making them important targets for cancer treatment. Hence, this review describes the various SMO-dependent and SMO-independent routes of GLI regulation in the tumorigenesis of multiple cancers in order to provide a holistic view of the paradigms of hedgehog signaling networks involving GLI regulation. An in-depth understanding of the complex interplay between GLI and various signaling elements could help inspire new therapeutic breakthroughs for the treatment of Hh-GLI-dependent cancers in the future. Lastly, we have presented an up-to-date summary of the latest findings concerning the use of Hh inhibitors in clinical developmental studies and discussed the challenges, perspectives, and possible directions regarding the use of SMO/GLI inhibitors in clinical settings.

Ovarian Cancer and Cancer Stem Cells-Cellular and Molecular Characteristics, Signaling Pathways, and Usefulness as a Diagnostic Tool in Medicine and Oncology

Simple Summary

Ovarian cancer is still a high-risk, metastatic disease, often diagnosed at a late stage. Difficulties in its treatment are associated with high resistance to chemotherapy and recurrence. Responsible for the malignant features of cancer are considered to be cancer stem cells (CSCs), which generate new cells by modifying various signaling pathways. Signaling pathways are crucial for the regulation of epithelial-mesenchymal transition, metastasis, and self-renewal of CSCs. New therapies based on the use of inhibitors that block CSC growth and proliferation signals are being investigated. The current histological classification of ovarian tumors, their epidemiology, and the recent knowledge of ovarian CSCs, with particular emphasis on their molecular basis, are important considerations.

Abstract

Despite the increasing development of medicine, ovarian cancer is still a high-risk, metastatic disease that is often diagnosed at a late stage. In addition, difficulties in its treatment are associated with high resistance to chemotherapy and frequent relapse. Cancer stem cells (CSCs), recently attracting significant scientific interest, are considered to be responsible for the malignant features of tumors. CSCs, as the driving force behind tumor development, generate new cells by modifying different signaling pathways. Moreover, investigations on different types of tumors have shown that signaling pathways are key to epithelial-mesenchymal transition (EMT) regulation, metastasis, and self-renewal of CSCs. Based on these established issues, new therapies are being investigated based on the use of inhibitors to block CSC growth and proliferation signals. Many reports indicate that CSC markers play a key role in cancer metastasis, with hopes placed in their targeting to block this process and eliminate relapses. Current histological classification of ovarian tumors, their epidemiology, and the most recent knowledge of ovarian CSCs, with particular emphasis on their molecular background, are important aspects for consideration. Furthermore, the importance of signaling pathways involved in tumor growth, development, and metastasis, is also presented.

The role of MMP-14 in ovarian cancer: a systematic review

AIM

In order to evaluate the role of MMP-14 in ovarian cancer, a systematic review was conducted.

METHODS

In March 2020, a search in Pubmed was performed with MMP-14 and ovarian cancer as search terms. After exclusion of the references not on MMP-14 or ovarian cancer or not in English, the studies found were classified into two categories: basic research and clinicopathological research.

RESULTS

In total, 94 references were found of which 33 were excluded. Two additional articles were found in the reference lists of the included studies. Based on the full texts, another 4 were excluded. Eventually, 59 studies were included in the review, 32 on basic research and 19 on clinicopathological research. 8 studies fell in both categories. The basic research studies show that MMP-14 plays an important role in ovarian cancer in the processes of proliferation, invasion, angiogenesis and metastasis. In clinocopathological research, MMP-14 expression is found in most tumours with characteristics of poor prognosis but this immunohistochemical MMP-14 determination does not seem to be an independent predictor of prognosis.

CONCLUSIONS

From this systematic review of the literature concerning MMP-14 in ovarian cancer it becomes clear that MMP-14 plays various important roles in the pathophysiology of ovarian cancer. The exact translation of these roles in the pathophysiology to the importance of MMP-14 in clinicopathological research in ovarian cancer and possible therapeutic role of anti-MMP-14 agents needs further elucidation.

Sonic Hedgehog signaling pathway in gynecological and genitourinary cancer (Review)

Cancers of the urinary tract, as well as those of the female and male reproductive systems, account for a large percentage of malignancies worldwide. Mortality is frequently affected by late diagnosis or therapeutic difficulties. The Sonic Hedgehog (SHH) pathway is an evolutionary conserved molecular cascade, which is mainly associated with the development of the central nervous system in fetal life. The present review aimed to provide an in‑depth summary of the SHH signaling pathway, including the characterization of its major components, the mechanism of its upstream regulation and non‑canonical activation, as well as its interactions with other cellular pathways. In addition, the three possible mechanisms of the cellular SHH cascade in cancer tissue are discussed. The aim of the present review was to summarize significant findings with regards to the expression of the SHH pathway components in kidney, bladder, ovarian, cervical and prostate cancer. Reports associated with common deficits and de‑regulations of the SHH pathway were summarized, despite the differences in molecular and histological patterns among these malignancies. However, currently, neither are SHH pathway elements included in panels of prognostic/therapeutic molecular patterns in any of the discussed cancers, nor have the drugs targeting SMO or GLIs been approved for therapy. The findings of the present review may support future studies on the treatment of and/or molecular targets for gynecological and genitourinary cancers.

The Cancer Stem Cell Niche in Ovarian Cancer and Its Impact on Immune Surveillance

Ovarian cancer is an aggressive gynaecological cancer with extremely poor prognosis, due to late diagnosis as well as the development of chemoresistance after first-line therapy. Research advances have found stem-like cells present in ovarian tumours, which exist in a dynamic niche and persist through therapy. The stem cell niche interacts extensively with the immune and non-immune components of the tumour microenvironment. Significant pathways associated with the cancer stem cell niche have been identified which interfere with the immune component of the tumour microenvironment, leading to immune surveillance evasion, dysfunction and suppression. This review aims to summarise current evidence-based knowledge on the cancer stem cell niche within the ovarian cancer tumour microenvironment and its effect on immune surveillance. Furthermore, the review seeks to understand the clinical consequences of this dynamic interaction by highlighting current therapies which target these processes.

The Role of Hedgehog Pathway in Female Cancers

Background:

The hedgehog pathway (HH) is one of the key regulators involved in many biological events. Malfunction of this pathway is associated with a variety of diseases including several types of cancers.

Methods:

We collected data from public databases and conducted a comprehensive search linking the HH pathway with female cancers. In addition, we overviewed clinical trials of targeting HH pathway in female cancers.

Results:

The activation of HH pathway and its role in female cancers, including breast cancer, ovarian cancer, cervical cancer, endometrial cancer, and uterine leiomyosarcoma were summarized. Treatment options targeting SMO and GLI in HH pathway were reviewed and discussed.

Conclusions:

The hedgehog pathway was shown to be activated in several types of female cancers. Therefore, targeting HH pathway may be considered as a therapeutic option to be acknowledged in the treatment of female cancers.

The Hedgehog signaling pathway promotes chemotherapy resistance via multidrug resistance protein 1 in ovarian cancer

Various studies have revealed that the Hedgehog (Hh) signaling pathway promotes ovarian cancer invasion, migration and drug resistance. Previous studies by our group have identified a set of genes, including multidrug resistance gene 1 (MDR1), that are regulated by Hh signaling in ovarian cancer. However, the association between Hh signaling activation and MDR1 expression requires further validation. In the present study, reverse transcription-quantitative PCR or western blot assays were used to evaluate the mRNA and protein expression levels of MDR1, Sonic Hh (Shh), glioma-associated oncogene 2 (Gli2), Gli1 and γ-phosphorylated H2A.X variant histone (γ-H2AX). MTT and colony-formation assays were performed to determine the effect of cisplatin (DDP) after inhibiting the Hh pathway in ovarian cancer cells. The results indicated that MDR1, Gli2 and Shh levels were much higher in SK-OV-3 cells with acquired DDP resistance than in native SK-OV-3 cells. ES-2 cells with overexpression of Gli2 were capable of efficiently forming colonies in the presence of low DDP concentrations. By contrast, Gli2 knockdown in SK-OV-3 cells decreased the colony-forming ability under the same concentration of DDP. As determined by MTT assays, knockdown of Gli2 or targeting of the Hh signaling pathway with either Gli-antagonist 61 (GANT61) or cyclopamine, in combination with DDP treatment, diminished the viability of ES-2 and SK-OV-3 cells, whereas Gli2 overexpression increased the viability of ES-2 cells in the presence of DDP. Knockdown of Gli2 or targeting the Hh signaling pathway with GANT61 also increased γ-H2AX levels but decreased the expression of MDR1 in the presence of DDP. MDR1 expression is regulated by the Hh signaling pathway and is likely a downstream transcription factor of Gli2. In conclusion, targeting the Hh signaling pathway increases the sensitivity of ovarian cancer to DDP. MDR1 is a target gene of the Hh signaling pathway and this pathway may affect chemoresistance of ovarian cancer to DDP via MDR1.

Carcinoma-Associated Mesenchymal Stem Cells Promote Chemoresistance in Ovarian Cancer Stem Cells via PDGF Signaling

Within the ovarian cancer tumor microenvironment, cancer stem-like cells (CSC) interact with carcinoma associated mesenchymal stem/stromal cells (CA-MSC) through multiple secreted cytokines and growth factors. These paracrine interactions have been revealed to cause enrichment of CSC and their chemoprotection; however, it is still not known if platelet-derived growth factor (PDGF) signaling is involved in facilitating these responses. In order to probe this undiscovered bidirectional communication, we created a model of ovarian malignant ascites in the three-dimensional (3D) hanging drop heterospheroid array, with CSC and CA-MSC. We hypothesized that PDGF secretion by CA-MSC increases self-renewal, migration, epithelial to mesenchymal transition (EMT) and chemoresistance in ovarian CSC. Our results indicate that PDGF signaling in the CSC-MSC heterospheroids significantly increased stemness, metastatic potential and chemoresistance of CSC. Knockdown of PDGFB in MSC resulted in abrogation of these phenotypes in the heterospheroids. Our studies also reveal a cross-talk between PDGF and Hedgehog signaling in ovarian cancer. Overall, our data suggest that when the stromal signaling via PDGF to ovarian CSC is blocked in addition to chemotherapy pressure, the tumor cells are significantly more sensitive to chemotherapy. Our results emphasize the importance of disrupting the signals from the microenvironment to the tumor cells, in order to improve response rates. These findings may lead to the development of combination therapies targeting stromal signaling (such as PDGF and Hedgehog) that can abrogate the tumorigenic, metastatic and platinum resistant phenotypes of ovarian CSC through additional investigations.

Targeting Cancer Stem Cells to Overcome Therapy Resistance in Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy due to its late detection and high recurrence rate. Resistance to conventional platinum-based therapies and metastasis are attributed to a population of cells within tumors called cancer stem cells, which possess stem-like features and are able to recapitulate new tumors. Recent studies have deepened the understanding of the biology of ovarian cancer stem cells and their special properties and have identified multiple markers and signaling pathways responsible for their self-renewal abilities. Targeting cancer stem cells represents the most promising strategy for overcoming therapy resistance and reducing mortality in ovarian cancer, but further efforts must be made to improve our understanding of the mechanisms involved in therapy resistance. In this review, we summarize our current knowledge about ovarian cancer stem cells, their involvement in metastasis and their interactions with the tumor microenvironment; we also discuss the therapeutic approaches that are being developed to target them to prevent tumor relapse.

The Diagnosis, Treatment, Prognosis and Molecular Pathology of Borderline Ovarian Tumors: Current Status and Perspectives

Borderline ovarian tumors (BOTs) are a type of low malignant potential tumor that is typically associated with better outcomes than ovarian cancer. Indeed, its 10-year survival rate is as high as 95%. However, there is a small subset of patients who experience relapse and eventually die. It has been shown that the prognosis of BOTs was based on pathological diagnosis, the age at diagnosis, pre-operative carbohydrate antigen 125 level, invasive implants, and micropapillary patterns. Now the molecular-targeted therapy and molecular-genetic diagnosis have developed into a form of precision medicine. Recent studies on extensive molecular characterizations and molecular pathological mechanisms of BOTs have helped us understand the genomic landscapes of BOTs, and therefore BOTs could be reclassified into biologically and clinically more accurate and effective subtypes. The purpose of this review is to summarize current status for the diagnosis and treatment of BOTs and to describe the research progress on molecular pathologies, with a goal of providing a theoretical perspective for the diagnosis and treatment of BOTs.

The hedgehog pathway regulates cancer stem cells in serous adenocarcinoma of the ovary

PURPOSE

Signaling by cancer stem cells (CSCs) is known to occur at least in part through conserved developmental pathways. Here, the role of one of these pathways, i.e., the hedgehog pathway, was evaluated in high-grade serous ovarian carcinoma (HGSOC).

METHODS AND RESULTS

We found that in HGSOC, hedgehog inhibitors (HHIs) GANT61, LDE225 and GDC0449 reduced or inhibited the formation of spheroids enriched in CSCs. Primary malignant cells (PMCs) in ascites from HGSOC patients cultured in the presence of HHIs showed significant reduction in CSCs. Sonic hedgehog (SHH) significantly increased the expression of ALDH1A1, which was inhibited by GANT61. In the presence of a SHH neutralizing antibody (5E1), a significant reduction in the number of spheroids was observed in HGSOC-derived cell lines. Further, the motility, migration and clonogenic growth of the cells were significantly reduced by HHIs. In the presence of GANT61, a reduction of cells from PMCs in the G0 phase of the cell cycle was observed. The magnitude of difference in expression of Gli1 in tumors from the same HGSOC patients at presentation and at interval debulking surgery was greater in patients who had a recurrence on follow up. GANT61 also significantly inhibited the growth of CSCs in nude mice. Finally, RNA sequencing of HGSOC cells treated with GANT61 showed a significantly reduced expression of CSC markers.

CONCLUSIONS

Our results indicate that the hedgehog pathway plays an important role in maintaining the integrity of CSCs in HGSOC and could be a potential therapeutic target.

The transcription factor GLI1 cooperates with the chromatin remodeler SMARCA2 to regulate chromatin accessibility at distal DNA regulatory elements

The transcription factor GLI1 (GLI family zinc finger 1) plays a key role in the development and progression of multiple malignancies. To date, regulation of transcriptional activity at target gene promoters is the only molecular event known to underlie the oncogenic function of GLI1. Here, we provide evidence that GLI1 controls chromatin accessibility at distal regulatory regions by modulating the recruitment of SMARCA2 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 2) to these elements. We demonstrate that SMARCA2 endogenously interacts with GLI1 and enhances its transcriptional activity. Mapping experiments indicated that the C-terminal transcriptional activation domain of GLI1 and SMARCA2's central domains, including its ATPase motif, are required for this interaction. Interestingly, similar to SMARCA2, GLI1 overexpression increased chromatin accessibility, as indicated by results of the micrococcal nuclease assay. Further, results of assays for transposase-accessible chromatin with sequencing (ATAC-seq) after GLI1 knockdown supported these findings, revealing that GLI1 regulates chromatin accessibility at several regions distal to gene promoters. Integrated RNA-seq and ATAC-seq data analyses identified a subset of differentially expressed genes located in cis to these regulated chromatin sites. Finally, using the GLI1-regulated gene HHIP (Hedgehog-interacting protein) as a model, we demonstrate that GLI1 and SMARCA2 co-occupy a distal chromatin peak and that SMARCA2 recruitment to this HHIP putative enhancer requires intact GLI1. These findings provide insights into how GLI1 controls gene expression in cancer cells and may inform approaches targeting this oncogenic transcription factor to manage malignancies.

Transcriptome analysis during photostimulated recrudescence reveals distinct patterns of gene regulation in Siberian hamster ovaries†

In Siberian hamsters, exposure to short days (SDs, 8 h light:16 h dark) reduces reproductive function centrally by decreasing gonadotropin secretion, whereas subsequent transfer of photoinhibited hamsters to stimulatory long days (LDs, 16 L:8 D) promotes follicle stimulating hormone (FSH) release inducing ovarian recrudescence. Although differences between SD and LD ovaries have been investigated, a systematic investigation of the ovarian transcriptome across photoperiod groups to identify potentially novel factors that contribute to photostimulated restoration of ovarian function had not been conducted. Hamsters were assigned to one of four photoperiod groups: LD to maintain ovarian cyclicity, SD to induce ovarian regression, or post transfer (PT), where females housed in SD for 14-weeks were transferred to LD for 2-days or 1-week to reflect photostimulated ovaries prior to (PTd2) and following (PTw1) the return of systemic FSH. Ovarian RNA was extracted to create RNA-sequencing libraries and short-read sequencing Illumina assays that mapped and quantified the ovarian transcriptomes (n = 4/group). Ovarian and uterine masses, plasma FSH, and numbers of antral follicles and corpora lutea decreased in SD as compared to LD ovaries (P < 0.05). When reads were aligned to the mouse genome, 18 548 genes were sufficiently quantified. Most of the differentially expressed genes noted between functional LD ovaries and regressed SD ovaries; however, five main expression patterns were identified across photoperiod groups. These results, generally corroborated by select protein immunostaining, provide a map of photoregulated ovary function and identify novel genes that may contribute to the photostimulated resumption of ovarian activity.

Hedgehog Signaling for Urogenital Organogenesis and Prostate Cancer: An Implication for the Epithelial-Mesenchyme Interaction (EMI)

Hedgehog (Hh) signaling is an essential growth factor signaling pathway especially in the regulation of epithelial-mesenchymal interactions (EMI) during the development of the urogenital organs such as the bladder and the external genitalia (EXG). The Hh ligands are often expressed in the epithelia, affecting the surrounding mesenchyme, and thus constituting a form of paracrine signaling. The development of the urogenital organ, therefore, provides an intriguing opportunity to study EMI and its relationship with other pathways, such as hormonal signaling. Cellular interactions of prostate cancer (PCa) with its neighboring tissue is also noteworthy. The local microenvironment, including the bone metastatic site, can release cellular signals which can affect the malignant tumors, and vice versa. Thus, it is necessary to compare possible similarities and divergences in Hh signaling functions and its interaction with other local growth factors, such as BMP (bone morphogenetic protein) between organogenesis and tumorigenesis. Additionally, this review will discuss two pertinent research aspects of Hh signaling: (1) the potential signaling crosstalk between Hh and androgen signaling; and (2) the effect of signaling between the epithelia and the mesenchyme on the status of the basement membrane with extracellular matrix structures located on the epithelial-mesenchymal interface.

SPOP Regulates The Biological Mechanism Of Ovarian Cancer Cells Through The Hh Signaling Pathway

Background

Ovarian cancer is characterized by high metastatic potential and high mortality. More than 80% of primary ovarian malignancies are epithelial ovarian cancers. There is increasing evidence that Speckle-type POZ protein (SPOP) is highly correlated with the development of various types of cancer. However, the effects of SPOP on epithelial ovarian cancer and the associated molecular mechanisms remain unclear.

Materials and methods

We compared SPOP expression between epithelial ovarian cancer tissues and normal ovarian tissues by using immunohistochemical staining. To determine the role of SPOP in epithelial ovarian cancer cells, we overexpressed or knocked down SPOP in the epithelial ovarian cancer cell line OVCAR-3 using lentiviral vectors.

Results

Our results from the present study indicated that SPOP expression was significantly downregulated in human epithelial ovarian cancer and was associated with the FIGO stage and the histopathologic grading of the tumor. The overexpression and knockdown experiments revealed that SPOP inhibited proliferation while promoting apoptosis in ovarian cancer cells. Inhibition of SPOP mis-activated the Hedgehog (Hh) signaling pathway, thereby inhibiting apoptosis in ovarian cancer cells.

Conclusion

SPOP suppresses proliferation and promotes apoptosis in human ovarian cancer cells by inhibiting the Hh signaling pathway, offering the possibility of new approaches for the treatment of ovarian cancer.

The Role of Sonic Hedgehog Signaling in the Tumor Microenvironment of Oral Squamous Cell Carcinoma

Sonic hedgehog (SHH) and its signaling have been identified in several human cancers, and increased levels of SHH expression appear to correlate with cancer progression. However, the role of SHH in the tumor microenvironment (TME) of oral squamous cell carcinoma (OSCC) is still unclear. No studies have compared the expression of SHH in different subtypes of OSCC and focused on the relationship between the tumor parenchyma and stroma. In this study, we analyzed SHH and expression of its receptor, Patched-1 (PTCH), in the TME of different subtypes of OSCC. Fifteen endophytic-type cases (ED type) and 15 exophytic-type cases (EX type) of OSCC were used. H&E staining, immunohistochemistry (IHC), double IHC, and double-fluorescent IHC were performed on these samples. ED-type parenchyma more strongly expressed both SHH and PTCH than EX-type parenchyma. In OSCC stroma, CD31-positive cancer blood vessels, CD68- and CD11b-positive macrophages, and α-smooth muscle actin-positive cancer-associated fibroblasts partially expressed PTCH. On the other hand, in EX-type stroma, almost no double-positive cells were observed. These results suggest that autocrine effects of SHH induce cancer invasion, and paracrine effects of SHH govern parenchyma-stromal interactions of OSCC. The role of the SHH pathway is to promote growth and invasion.

Hypoxia induced Sonic Hedgehog signaling regulates cancer stemness, epithelial-to-mesenchymal transition and invasion in cholangiocarcinoma

Aberrant activation of Sonic Hedgehog (SHH) pathway has been implicated in a variety of cancers including cholangiocarcinoma (CC); however, the influencing factors are still unknown. Additionally, intratumoral hypoxia is known to contribute towards therapeutic resistance through modulatory effects on various pathways. In this study, we investigated the relationship between hypoxia and SHH pathway activation and the effect of this interplay on cancer stemness and epithelial-to- mesenchymal transition (EMT) during cholangiocarcinogenesis. Hypoxia promoted SHH pathway activation, evidenced by upregulated SHH and SMO levels, and enhanced glioma-associated oncogene homolog 1 (GLI1) nuclear translocation; whereas silencing of HIF-1α impaired SHH upregulation. Hypoxia also enhanced the expression of cancer stem cell (CSC) transcription factors (NANOG, Oct4, SOX2), CD133 and EMT markers (N-cadherin, Vimentin), thereby supporting invasion. Cyclopamine treatment suppressed hypoxia induced SHH pathway activation, consequently reducing invasiveness by downregulating the expression of CSC transcription factors, CD133 and EMT. Cyclopamine induced apoptosis in CC cells under hypoxia, suggesting that hypoxia induced activation of SHH pathway has modulatory effects on CC progression. Therefore, SHH signaling is proposed as a target for CC treatment, which is refractory to standard chemotherapy.

Downregulation of Rab23 inhibits proliferation, invasion, and metastasis of human ovarian cancer

Previously, we reported that the expression of human epididymis protein (HE4) was correlated with the expression of RAB23 in ovarian cancer cells. Rab23 is a member of the Ras-related small GTPase superfamily, which plays a key role in the Sonic Hedgehog (Shh) signaling pathway. However, the function of Rab23 in ovarian cancer remains unclear. In this study, we explored the location and expression of Rab23 in ovarian cancer tissues and cells (CaoV3 and A2780), and further investigated the function and potential mechanism of Rab23 in malignant biological behaviors including the epithelial-mesenchymal transition (EMT) process in ovarian cancer for the first time. Rab23 is highly expressed in ovarian cancer tissues and associated with advanced stage, and shortened overall survival time of ovarian cancer patients. We are the first to report that human epididymis protein (HE4) can regulate the expression of the Rab23 protein, and that knockdown of RAB23 decreases the proliferation, invasion, and migration abilities as well as inhibits the epithelial-mesenchymal transition (EMT) process in ovarian cancer cells. Furthermore, downregulation of Rab23 significantly inhibited Shh-Gli1 and PI3K-AKT signaling pathways. Collectively, our results indicate that Rab23 plays a critical role in the malignant biological behavior of ovarian cancer and may serve as a potential biomarker and therapeutic target for ovarian cancer.

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.

WIF-1 and Ihh Expression and Clinical Significance in Patients With Lung Squamous Cell Carcinoma and Adenocarcinoma

This study investigated the expression of wingless-type inhibitory factor-1 (WIF-1) and Ihh protein in tumor tissues and their clinical significance in patients with lung squamous cell carcinoma and adenocarcinoma. The expression of WIF-1 and Ihh protein in 74 squamous cell carcinomas and 76 adenocarcinomas was measured by immunohistochemistry. The percentage of positive WIF-1 protein expression was significantly higher, while positive Ihh protein expression was significantly lower in patients with well-differentiated lung squamous cell carcinoma and adenocarcinoma, tumor node metastasis (TNM) stage I disease, and lymph node metastasis than that in patients with poorly differentiated tumor, TNM stage III disease, and lymph node metastasis (P<0.05, <0.01). Kaplan-Meier survival analysis showed that TNM stage and lymph node metastasis were significantly associated with the mean overall survival of patients with lung squamous cell carcinoma and adenocarcinoma (P<0.05 or <0.01). Patients with lung squamous cell carcinoma (P=0.037) and adenocarcinoma (P=0.001) with positive Ihh protein expression survived significantly shorter than patients with negative Ihh protein expression. In contrast, no significant difference in mean survival was observed in patients with lung squamous cell carcinoma and adenocarcinoma with positive and negative WIF-1 protein expression (P>0.05). Ihh is a marker for poor prognosis in patients with lung squamous cell carcinoma and adenocarcinoma. WIF-1 is not a predictive marker for lung cancer.

Role of Hedgehog Signaling in Vasculature Development, Differentiation, and Maintenance

The role of Hedgehog (Hh) signaling in vascular biology has first been highlighted in embryos by Pepicelli et al. in 1998 and Rowitch et al. in 1999. Since then, the proangiogenic role of the Hh ligands has been confirmed in adults, especially under pathologic conditions. More recently, the Hh signaling has been proposed to improve vascular integrity especially at the blood–brain barrier (BBB). However, molecular and cellular mechanisms underlying the role of the Hh signaling in vascular biology remain poorly understood and conflicting results have been reported. As a matter of fact, in several settings, it is currently not clear whether Hh ligands promote vessel integrity and quiescence or destabilize vessels to promote angiogenesis. The present review relates the current knowledge regarding the role of the Hh signaling in vasculature development, maturation and maintenance, discusses the underlying proposed mechanisms and highlights controversial data which may serve as a guideline for future research. Most importantly, fully understanding such mechanisms is critical for the development of safe and efficient therapies to target the Hh signaling in both cancer and cardiovascular/cerebrovascular diseases.

Activation of hedgehog signaling associates with early disease progression in chronic lymphocytic leukemia

Targeted sequencing of 103 leukemia-associated genes in leukemia cells from 841 treatment-naive patients with chronic lymphocytic leukemia (CLL) identified 89 (11%) patients as having CLL cells with mutations in genes encoding proteins that putatively are involved in hedgehog (Hh) signaling. Consistent with this finding, there was a significant association between the presence of these mutations and the expression of GLI1 (χ2 test, P < .0001), reflecting activation of the Hh pathway. However, we discovered that 38% of cases without identified mutations also were GLI1+ Patients with GLI1+ CLL cells had a shorter median treatment-free survival than patients with CLL cells lacking expression of GLI1 independent of IGHV mutation status. We found that GANT61, a small molecule that can inhibit GLI1, was highly cytotoxic for GLI1+ CLL cells relative to that of CLL cells without GLI1. Collectively, this study shows that a large proportion of patients have CLL cells with activated Hh signaling, which is associated with early disease progression and enhanced sensitivity to inhibition of GLI1.

Sonic Hedgehog Ligand: A Role in Formation of a Mesenchymal Niche in Human Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterised by desmoplasia, thought to support progression and chemotherapeutic resistance. The Hedgehog pathway is known to play an important role in this cancer. While the upregulation of Sonic hedgehog (Shh) in the epithelium of PDAC is known, we investigated its expression in the tumour microenvironment in order to find new targets for new chemotherapeutical approaches. Immunohistochemistry was used for the investigation of Shh and Vimentin in primary human pancreatic tissues. Gene (qRT-PCR) and protein (immunofluorescence) expression of Shh, αSMA (a marker of the mesenchymal phenotype) and periostin (a marker of mesenchymal cells within a mixed population) were investigated in in vitro cell models. Shh expression was significantly upregulated in the stromal and epithelial compartments of poorly-differentiated PDAC samples, with a strong correlation with the amount of stroma present. Characterisation of stromal cells showed that there was expression of Shh ligand in a mixed population comprising αSMA+ myofibroblasts and αSMA- mesenchymal stem cells. Moreover, we demonstrated the interaction between these cell lines by showing a higher rate of mesenchymal cell proliferation and the upregulation of periostin. Therefore, targeting stromal Shh could affect the equilibrium of the tumour microenvironment and its contribution to tumour growth.

Aberrant Activation Of Hedgehog Signalling Promotes Cell Migration And Invasion Via Matrix Metalloproteinase-7 In Ovarian Cancer Cells

Background: Accumulating evidence indicates that aberrant activation of the Hedgehog (Hh) signalling pathway by Glioma-associated oncogene (Gli) transcription factors is involved in the aggressive progression of cancers, including ovarian cancer. Whereas the molecular mechanism underlying this phenomenon remains unelucidated. Matrix metalloproteinase-7 (MMP-7) facilitates degradation of the extracellular matrix, promoting the invasion of tumour cells, and is associated with cancer progression and metastasis. In previous reports, we identified a set of genes regulated by Hh signalling in ovarian tumour cells among which MMP-7 was identified as a potential Hh target gene candidate. However, establishing an association between Hh signalling activation and MMP-7 expression requires further validation, and the function of this regulation remains unknown.

Methods: A cDNA microarray was utilized to identify potential downstream targets of Hh signalling. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to evaluate mRNA expression, and immunoblotting (IB) was conducted to evaluate protein expression. The invasive and migratory capabilities of tumour cells were tested with the transwell and wound healing assays, respectively. The mRNA levels of Gli2 and MMP-7 in normal ovarian tissues and cancerous tissues in various stages together with the corresponding clinical information were acquired from the indicated GEO datasets to elucidate associations between MMP-7 expression and cancer progression and prognosis. Additionally, immunohistochemistry (IHC) was performed in multiple ovarian cancers, benign tumours and normal tissues to evaluate Gli2 and MMP-7 protein expression.

Results: MMP-7 expression was regulated by the Hh ligand, antagonist and downstream transcript factor Gli2, demonstrating this gene as an Hh target. MMP-7 facilitated the invasion and migration of ovarian tumour cells, indicating its key function in ovarian cancer progression. IHC analysis demonstrated abnormally increased Gli2 and MMP-7 expression levels in benign tumours and ovarian cancer tissues. Moreover, high MMP-7 levels were significantly associated with poor overall survival (OS) and poor progression-free survival (PFS) in ovarian cancer patients.

Conclusion: Aberrant activation of the Hh-Gli-MMP-7 signalling axis is essential for acceleration of the progression and metastasis of human ovarian cancer, implicating its use as a novel therapeutic target of ovarian cancer. In addition, MMP-7 can potentially serve as a prognostic marker of ovarian cancer.

Hedgehog Signaling in Cancer: A Prospective Therapeutic Target for Eradicating Cancer Stem Cells

The Hedgehog (Hh) pathway is a signaling cascade that plays a crucial role in many fundamental processes, including embryonic development and tissue homeostasis. Moreover, emerging evidence has suggested that aberrant activation of Hh is associated with neoplastic transformations, malignant tumors, and drug resistance of a multitude of cancers. At the molecular level, it has been shown that Hh signaling drives the progression of cancers by regulating cancer cell proliferation, malignancy, metastasis, and the expansion of cancer stem cells (CSCs). Thus, a comprehensive understanding of Hh signaling during tumorigenesis and development of chemoresistance is necessary in order to identify potential therapeutic strategies to target various human cancers and their relapse. In this review, we discuss the molecular basis of the Hh signaling pathway and its abnormal activation in several types of human cancers. We also highlight the clinical development of Hh signaling inhibitors for cancer therapy as well as CSC-targeted therapy.

Sonic Hedgehog Expression is Associated with Lymph Node Invasion in Urothelial Bladder Cancer

Bladder cancer (BC) is a deadly disease characterized by high recurrence rates and frequent progression to an aggressive phenotype. Dysregulation of various signaling pathways have been implicated in BC tumorigenesis, however, the clinical relevance of sonic hedgehog pathway (Shh) remains under investigated. The aim of the current study was to analyze the prognostic value of Shh expression in patients with bladder carcinoma. Immunohistochemical expression of Shh was performed using tissue microarray with 128 specimens from bladder cancer patients. Kaplan-meier survival was analysed and correlation between Shh protein expression and patients' clinicopathological parameters wasexamined using Fisher's exact test. The immuno-staining results revealed that Shh protein exhibits cytoplasmic localization and is expressed in 49% of the analyzed bladder cancer cohort. Our data indicated that high Shh expression significantly correlated with increased lymph node metastasis (p = 0.02), however no association was reported between Shh expression and other clinicopatholigical parameters. High expression of sonic hedgehog was associated with lymph node invasion which may indicate that Shh might play an important role in progression and metastasis of bladder cancer.

Dihydroartemisinin induces apoptosis and inhibits proliferation, migration, and invasion in epithelial ovarian cancer via inhibition of the hedgehog signaling pathway

Dihydroartemisinin (DHA), the primary of artemisinin extracted from the traditional Chinese medicine Artemisia annua, has been used in malaria treatment for a long time. Recently, many studies have indicated that, in addition to antimalarial effects, DHA also exhibits anticancer activity in certain types of neoplasms, including ovarian cancer. However, the precise anti‐ovarian cancer mechanism of DHA is still unclear. Abnormal activation of the hedgehog (Hh) pathway is closely related to tumorigenesis and progression of ovarian cancer. We performed this study to elucidate the effects of DHA on the biological behavior of ovarian cancer cells and to determine its effects on the Hh signaling pathway. CCK8 assays and flow cytometry were used to evaluate the effects of DHA on cell viability and apoptosis in both ovarian cancer cells and HOSEPICs (human ovarian surface epithelial cells) in response to DHA treatment. Transwell membrane chambers were used to analyze the effects of DHA on the migration and invasion of epithelial ovarian cancer cells following treatment with DHA. The impact of DHA on Hh signaling was analyzed by RT‐qPCR and Western blot. DHA significantly inhibited proliferation, migration, and invasion of ovarian cancer cells, and induced apoptosis in vitro. In contrast, DHA had few effects on cell proliferation and apoptosis in HOSEPICs. DHA inhibited the hedgehog signaling pathway. Furthermore, DHA inhibited purmorphamine (Hh signaling pathway agonist)‐induced cell proliferation, cell migration, and cell invasion and the inhibition of apoptosis. Importantly, DHA enhanced GANT61 (hedgehog signaling pathway inhibitor)‐induced apoptosis and the inhibition of cell viability, migratory capacity, and invasive ability. This study demonstrates that DHA inhibits cell viability, migration, and invasion, as well as induces apoptosis in epithelial ovarian cancer through suppression of the Hh signaling pathway.

Can Stemness and Chemoresistance Be Therapeutically Targeted via Signaling Pathways in Ovarian Cancer?

Ovarian cancer is the most lethal gynecological malignancy. Poor overall survival, particularly for patients with high grade serous (HGS) ovarian cancer, is often attributed to late stage at diagnosis and relapse following chemotherapy. HGS ovarian cancer is a heterogenous disease in that few genes are consistently mutated between patients. Additionally, HGS ovarian cancer is characterized by high genomic instability. For these reasons, personalized approaches may be necessary for effective treatment and cure. Understanding the molecular mechanisms that contribute to tumor metastasis and chemoresistance are essential to improve survival rates. One favored model for tumor metastasis and chemoresistance is the cancer stem cell (CSC) model. CSCs are cells with enhanced self-renewal properties that are enriched following chemotherapy. Elimination of this cell population is thought to be a mechanism to increase therapeutic response. Therefore, accurate identification of stem cell populations that are most clinically relevant is necessary. While many CSC identifiers (ALDH, OCT4, CD133, and side population) have been established, it is still not clear which population(s) will be most beneficial to target in patients. Therefore, there is a critical need to characterize CSCs with reliable markers and find their weaknesses that will make the CSCs amenable to therapy. Many signaling pathways are implicated for their roles in CSC initiation and maintenance. Therapeutically targeting pathways needed for CSC initiation or maintenance may be an effective way of treating HGS ovarian cancer patients. In conclusion, the prognosis for HGS ovarian cancer may be improved by combining CSC phenotyping with targeted therapies for pathways involved in CSC maintenance.

Expression of Numb and Gli1 in malignant pleural mesothelioma and their clinical significance

AIM OF STUDY

Malignant pleural mesothelioma (MPM) is a highly lethal and refractory to multimodal treatment tumor. Numb is considered as a tumor suppressor playing critical roles in determining cell fate and has been shown to target the oncogenic transcription factor Gli1 for Itch-dependent ubiquitination, resulting in suppression of the oncogenic sonic hedgehog signaling in medulloblastoma. This study was designed to analysis the role of Numb and Gli1 in MPM.

MATERIALS AND METHODS

Tissues of 61 MPM patients and 22 normal pleura as control were investigated. Numb and Gli1 expression were evaluated by immunohistochemistry. The associations with clinical and pathological parameters of the two markers were statistically analyzed, and the correlation between them was also demonstrated.

RESULTS

The expression levels of Numb with nuclear Gli1 exhibited a significant inverse correlation (r = -0.361 P < 0.05). In addition, Numb has an inverse correlation with ki-67 labeling index (P < 0.05), and nuclear Gli1 was found in associated with the tumor International Mesothelioma Interest Group-stage (P < 0.05). The overall survival was influenced by the expression of Numb (P < 0.05) and histological subtype (P < 0.05), further regression analysis showed that only histological subtype has a prognostic influence on survival (P < 0.05).

CONCLUSION

The results provide new evidence of Numb and Gli1 on the clinical characteristics of MPM, which may be helpful in clinical diagnosis and targeted therapy. Further research with larger sample size is needed.

Dehydroeffusol inhibits viability and epithelial-mesenchymal transition through the Hedgehog and Akt/mTOR signaling pathways in neuroblastoma cells

Neuroblastoma (NB) is the most predominant extracranial solid tumor of infancy in the world. However, current chemotherapy has limited efficacy for more advanced stages of NB due to acquired chemoresistance or acute toxicity in NB patients. Therefore, effective novel anti-NB drugs are desperately needed. The present study aimed to investigate the effects of dehydroeffusol (DHE), a phenanthrene isolated from J. effuses, on NB cells and its underlying mechanism. The results showed that DHE treatment effectively inhibited NB cell viability in a dose-dependent manner. Moreover, DHE treatment suppressed the epithelial-mesenchymal transition (EMT) process in NB cells by promoting the expression of E-cadherin (E-cad) and restraining the expressions of N-cadherin (N-cad) and vimentin. Also, the invasive capacity and expression of MMP-2 and MMP-9 in NB cells were inhibited by DHE. Furthermore, DHE suppressed the hedgehog (Hh) and the protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways in NB cells. In conclusion, DHE effectively inhibited the viability and EMT through inactivating the Hh and the Akt/mTOR signaling pathways in NB cells, providing a novel evidence that DHE may be a potential anti-NB drug candidate.

Overexpression of MYC binding protein promotes invasion and migration in gastric cancer

Gastric cancer (GC) is the second leading cause of cancer-associated mortality worldwide. Although the mortality rate of patients with GC has improved, it remains a significant health issue. The MYC proto-oncogene protein serves key roles in cellular proliferation, differentiation, transformation and apoptosis. Previous studies have identified the abnormal expression of MYC-binding protein (MYCBP) during tumorigenesis in multiple types of cancer. Furthermore, evidence demonstrates that the abnormal expression of MYCBP contributes to the invasion and migration of human cancer types, including colon cancer and glioma; however, its influence on GC remains unclear. In the present study, the expression of MYCBP in GC cells and tissues was analyzed by reverse transcription-quantitative polymerase chain reaction. Additionally, GC cell lines were transfected with small interfering RNAs against MYCBP or lymphoid enhancer-binding factor 1 (LEF-1) and assessed by in vitro transwell migration and invasion assays. The results indicated that the expression of MYCBP in GC cells and tissues was markedly increased compared with a normal gastric epithelial cell line and adjacent normal gastric mucosal tissues, respectively. Furthermore, MYCBP downregulation notably inhibited the metastatic capacity of GC cells, and LEF-1 knockdown was found to downregulate the expression of MYCBP. On the basis of the findings of the present study, MYCBP may be a direct target of the β-catenin/LEF-1 pathway via binding LEF-1, and could potentially be used as a biomarker for the diagnosis and prognosis of GC.

Aspirin inhibits the SHH/GLI1 signaling pathway and sensitizes malignant glioma cells to temozolomide therapy

Aberrant activation of sonic hedgehog (SHH)/glioma-associated oncogene homolog 1 (GLI1) pathway plays an important role in the tumorigenicity of malignant glioma cells and resistance to temozolomide (TMZ). Here we investigated the aspirin's antineoplastic molecular route by targeting SHH/GLI1 pathway and examined the feasibility of aspirin combined with TMZ therapy. Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) revealed that the activity of the SHH/GLI1 pathway was strongly inhibited by aspirin. Aspirin acted as the glioma growth-inhibitory and pro-apoptosis roles by inhibiting the SHH/GLI1 pathway and reprogramming the epithelial to mesenchymal transition (EMT). The immunofluorescence assay showed aspirin could prevent the nuclear translocation of GLI1 to inhibit its transcriptional regulation. The stable lentiviral overexpression of GLI1 reversed the DNA double strand breaks (DSBs) caused by the GANT61 and TMZ. Furthermore, aspirin combined with TMZ enhanced chemosensitivity and GLI1-induced chemoprotection was partly blocked by aspirin in vitro and in vivo. Collectively, aspirin has a therapeutic potential for SHH/GLI1 targeted therapy against glioma cells. Acquired activation of GLI1 protects glioma cells against TMZ therapy. Impairment of DNA DSBs repair activity might be involved in the route of aspirin-induced chemosensitivity. Combined aspirin with TMZ may be a promising strategy against malignant glioma.