Gastric cancer (GC) patients with hedgehog pathway activation: PTCH1 and GLI2 as independent prognostic factors. Target Oncol. 2013;8:271-280. [PMID: 23371028 DOI: 10.1007/s11523-013-0253-1]

Unraveling the influence of LncRNA in gastric cancer pathogenesis: a comprehensive review focus on signaling pathways interplay

Gastric cancers (GCs) are among the most common and fatal malignancies in the world. Despite our increasing understanding of the molecular mechanisms underlying GC, further biomarkers are still needed for more in-depth examination, focused prognosis, and treatment. GC is one among the long non-coding RNAs, or lncRNAs, that have emerged as key regulators of the pathophysiology of cancer. This comprehensive review focuses on the diverse functions of long noncoding RNAs (lncRNAs) in the development of GC and their interactions with important intracellular signaling pathways. LncRNAs affect GC-related carcinogenic signaling cascades including pathways for EGFR, PI3K/AKT/mTOR, p53, Wnt/β-catenin, JAK/STAT, Hedgehog, NF-κB, and hypoxia-inducible factor. Dysregulated long non-coding RNA (lncRNA) expression has been associated with multiple characteristics of cancer, such as extended growth, apoptosis resistance, enhanced invasion and metastasis, angiogenesis, and therapy resistance. For instance, lncRNAs such as HOTAIR, MALAT1, and H19 promote the development of GC via altering these pathways. Beyond their main roles, GC lncRNAs exhibit potential as diagnostic and prognostic biomarkers. The overview discusses CRISPR/Cas9 genome-modifying methods, antisense oligonucleotides, small molecules, and RNA interference as potential therapeutic approaches to regulate the expression of long noncoding RNAs (lncRNAs). An in-depth discussion of the intricate functions that lncRNAs play in the development of the majority of stomach malignancies is provided in this review. It provides the groundwork for future translational research in lncRNA-based whole processes toward GC by highlighting their carcinogenic effects, regulatory roles in significant signaling cascades, and practical scientific uses as biomarkers and therapeutic targets.

Implicating clinical utility of altered expression of PTCH1 & SMO in oral squamous cell carcinoma

INTRODUCTION

Oral cancer poses a significant burden on public health in India, with higher incidence and mortality rates. Despite advancements in treatment modalities, prognosis remains poor due to factors such as localized recurrence and lymph node metastasis, potentially influenced by cancer stem cells. Among signaling pathways implicated in CSC regulation, the Hedgehog pathway plays a crucial role in oral squamous cell carcinoma (OSCC).

MATERIAL & METHODS

97 OSCC patients' tissue samples were collected and subjected to RNA isolation, cDNA synthesis and quantitative real-time PCR to analyze PTCH1 and SMO expression. Protein expression was assessed through immunohistochemistry. Clinicopathological parameters were correlated with gene and protein expression. Statistical analysis included Pearson chi-square tests, co-relation co-efficient tests, Kaplan-Meier survival analysis and ROC curve analysis.

RESULTS

PTCH1 expression correlated with lymphatic permeation (p = 0.002) and tumor stage (p = 0.002), while SMO expression correlated with lymph node status (p = 0.034) and tumor stage (p = 0.021). PTCH1 gene expression correlated with lymph node status (p = 0.024). High PTCH1 gene expression was associated with shorter survival in tongue cancer patients. ROC curve analysis indicated diagnostic potential for PTCH1 and SMO gene and cytoplasmic SMO expression in distinguishing malignant tissues from adjacent normal tissues.

CONCLUSION

PTCH1 and SMO play a crucial role in oral cancer progression, correlating with tumor stages and metastatic potential. Despite not directly influencing overall survival, PTCH1 expression at specific anatomical sites hints at its prognostic implications. PTCH1 and SMO exhibit diagnostic potential, suggesting their utility as molecular markers in oral cancer management and therapeutic strategies.

Hedgehog signaling-related genomics signature for the accurate progress and prognosis prediction in gastric cancer

The Hedgehog pathway is thought to be closely associated with the progression of GC; however, a specific link between the Hedgehog pathway on the prognosis and immune infiltration of gastric cancer is still lacking. This study collected Hedgehog pathway-related genes. The Hedgehog pathway-related pattern were identified by consensus cluster analysis. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) were used to identify the biological functions which were significantly altered between predefined Cluster1 and Cluster2 in consensus clustering. The risk model of gastric cancer based on Hedgehog signaling pathway was constructed by univariate and multivariate COX regression, and the nomogram was constructed. The results showed that there were significant differences in the expression of Hedgehog pathway-related genes between the two groups. In addition, the constructed risk model was significantly correlated with the clinical prognosis and immune cell infiltration level of patients with gastric cancer. The model effectively predicted the efficacy of chemotherapy in GC patients and the sensitivity of drug treatment between groups. We systematically revealed the mechanism of Hedgehog pathway in gastric cancer and selected biomarkers with biological significance from a new perspective, providing potential direction for the treatment of gastric cancer.

Effects of an inhibitor of the SHH signaling pathway on endometrial cells of patients with endometriosis

BACKGROUND

Endometriosis is one of the most common gynecological diseases, and seriously reduces the quality of life of patients. However, the pathogenesis of this disease is unclear. Therefore, more studies are needed to elucidate its pathogenesis. Our previous publication found that the Sonic Hedgehog (SHH) signaling pathway was activated in endometriosis. This study tested whether SHH signaling in endometrial stromal cells (ESCs) was critical for the pathogenesis of endometriosis.

METHODS

To examine the effect of inhibiting the SHH signaling pathway on endometriosis, we first isolated ESCs from eutopic endometrial tissues of patients with or without endometriosis and identified the extracted cells by morphological observation and immunofluorescence. Then, we treated ESCs with the GLI inhibitor GANT61 and used CCK-8, wound healing and invasion assays to detect cell activities, such as proliferation, invasion and metastasis. Furthermore, we detected the expression of key proteins and proliferation markers of the SHH signaling pathway in the lesions of nude mice using immunochemistry.

RESULTS

We demonstrated that higher concentrations of GANT61 decreased the proliferation rate and migration distance of ESCs. We observed that GANT61 inhibited the invasion of ESCs. In addition, blockage of the SHH signaling pathway significantly reduced cell proliferation in vitro.

CONCLUSIONS

Our study suggested that inhibition of the SHH pathway is involved in cell proliferation and invasive growth in the pathogenesis of endometriosis.

Clinicopathologic and genomic characteristics of mucinous gastric adenocarcinoma

BACKGROUND

Mucinous gastric adenocarcinoma (MGC) is a rare but distinctive histologic subtype of gastric cancer (GC). The clinico-pathologic and genomic characteristics of MGC have not been well evaluated.

METHODS

We collected individual data from five cohorts targeting the microsatellite instability (MSI) of GC (n = 5089) to evaluate the clinico-pathologic characteristics of MGC. In addition, public genomic databases were used for genomic analysis. The characteristics of MGC were compared with those of non-mucinous GC (NMGC).

RESULTS

MGC (n = 158, 3.1%) showed distinctive characteristics in terms of age, sex, and TNM stage compared to NMGC (n = 4931). MGC was frequently associated with MSI-high (OR: 2.24, 95% confidence interval [CI] 1.44-3.40, p < 0.001), while mutually exclusive to the Epstein-Barr virus type. The prognosis of MGC was better than that of NMGC (adj.HR: 0.731, 95% CI 0.556-0.962, p = 0.025). There was no clear benefit from postoperative chemotherapy in MGC. TP53 was the main driver mutation in the MGC without recurrent variants. MGC was related to high expression of GPR120 and B3GNT6 and moderate regulation of epithelial-mesenchymal transition (EMT)-up signature with a high EMT-down signature, and those characteristics was related to favorable prognosis of GC (log-rank p = 0.044, p < 0.001, p < 0.001, respectively). MSI-H of MGC was associated with low cancer-associate fibroblasts but high CD274 (PD-L1) expression compared to microsatellite stable MGC, suggesting that immune checkpoint inhibitors may be useful for the MSI-H of MGC.

CONCLUSION

MGC could be a surrogate for performing MSI but not the EBV test in GC. Further, its genetic characteristics lead to a favorable prognosis for MGC.

Collagen type Ⅳ alpha 1 (COL4A1) silence hampers the invasion, migration and epithelial-mesenchymal transition (EMT) of gastric cancer cells through blocking Hedgehog signaling pathway

Gastric cancer (GC), which features high prevalence and mortality rate, remains the third most lethal cancer worldwide. The paper was designed to explore the impacts of collagen type Ⅳ alpha 1 (COL4A1) on GC, along with its potential mechanism. The mRNA and protein expressions of COL4A1 in GC cells were assessed by RT-qPCR and western blot. After depleting COL4A1, RT-qPCR and western blot were conducted again to check the transfection efficacy. With the application of CCK-8, wound healing and transwell, the capabilities of cells to proliferate, migrate and invade were appraised, respectively. Moreover, western blot tested the protein levels of factors involved in migration, proliferation, epithelial mesenchymal transition (EMT) and Hedgehog signaling. As a result, COL4A1 displayed elevated expression in GC tissues and cells while its knockdown inhibited the cell viability, migration, invasion and EMT in GC. According to Gene Set Enrichment Analysis (GSEA), COL4A1 was involved in the regulation of Hedgehog signaling pathway, which was then further verified by the detection of Hedgehog-related proteins. To figure out the relationship between COL4A1 and Hedgehog signaling pathway, we used purmorphamine, an agonist of Hedgehog, to treat GC cells, finding that COL4A1 blocked Hedgehog signaling to inhibit the aggressive phenotypes of GC cells. In short, COL4A1 silence was testified to exhibit suppressive effects on the malignant process of GC, suggesting that COL4A1 might be a potent hallmark for GC therapy.

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.

Synergistic inhibitory effect of Smo inhibitor jervine and its combination with decitabine can target Hedgehog signaling pathway to inhibit myelodysplastic syndrome cell line

OBJECTIVE

Hypomethylating agents (HMAs) have been reported to target the Sonic Hedgehog (Shh) signaling pathway in myelodysplastic syndrome (MDS). However, the synergistic inhibitory effect of Smo inhibitor jervine and its combination with decitabine in MUTZ-1 cell lines remains lacking.

METHODS

We used a CCK-8 assay to detect the in-vitro proliferation rate of MUTZ-1 cell lines. Besides, the Annexin V-FITC/PI double staining flow cytometry was utilized to detect the apoptosis rate and cell cycle changes. The expression levels of mRNA were quantified by using qRT-PCR, and the western blot was employed to detect the expression of proteins.

RESULTS

We found that the single-agent jervine or decitabine can significantly inhibit the proliferation rate of MUTZ-1 cell lines, and this inhibitory effect is time-dependent and concentration-dependent. The combined intervention of the jervine and decitabine can more significantly inhibit cell proliferation, induce cell apoptosis, and block the G1 phase of the cell cycle. The combined intervention of the two drugs significantly reduced Smo and G1i-1 mRNA expression in MUTZ-1 cells. Furthermore, after combining both of the drug treatments, the proteins levels of Smo, G1i-1, PI3K, p-AKT, Bcl2, and Cyclin Dl were significantly downregulated, and Caspase-3 is upregulated, indicating that jervine with its combination of decitabine might be effective for controlling the proliferation, apoptosis, and cell cycle.

CONCLUSION

The Smo inhibitor jervine and its combination with decitabine have a synergistic effect on the proliferation, cell cycle, and apoptosis of MUTZ-1 cells, and its mechanism may be achieved by interfering with the Shh signaling pathway.

Telomerase reverse transcriptase activates transcription of miR500A to inhibit Hedgehog signalling and promote cell invasiveness

Telomerase reverse transcriptase (TERT) maintains telomere homeostasis, thus ensuring chromosome stability and cell proliferation. In addition, several telomere-independent functions of human TERT have been described. In this study, we report that TERT binds directly to the TCF binding elements located upstream of the oncomiR miR500A, and induces its transcription. This function was independent of the telomerase activity, as shown with experiments using catalytically inactive TERT and inhibitors of TERT and the TERT RNA component. miR500A was in turn found to target three key components of the Hedgehog signalling pathway: Patched 1; Gli family zinc finger 3; and Cullin 3, thereby promoting cell invasion. Our results point to the crucial role of the TERT-miR500A-Hedgehog axis in tumour aggressiveness and highlight the therapeutic potential of targeting noncanonical TERT functions in cancer.

Hedgehog Signaling: Implications in Cancers and Viral Infections

The hedgehog (SHH) signaling pathway is primarily involved in embryonic gut development, smooth muscle differentiation, cell proliferation, adult tissue homeostasis, tissue repair following injury, and tissue polarity during the development of vertebrate and invertebrate organisms. GLIoma-associated oncogene homolog (GLI) family of zinc-finger transcription factors and smoothened (SMO) are the signal transducers of the SHH pathway. Both SHH ligand-dependent and independent mechanisms activate GLI proteins. Various transcriptional mechanisms, posttranslational modifications (phosphorylation, ubiquitination, proteolytic processing, SUMOylation, and acetylation), and nuclear-cytoplasmic shuttling control the activity of SHH signaling pathway proteins. The dysregulated SHH pathway is associated with bone and soft tissue sarcomas, GLIomas, medulloblastomas, leukemias, and tumors of breast, lung, skin, prostate, brain, gastric, and pancreas. While extensively studied in development and sarcomas, GLI family proteins play an essential role in many host-pathogen interactions, including bacterial and viral infections and their associated cancers. Viruses hijack host GLI family transcription factors and their downstream signaling cascades to enhance the viral gene transcription required for replication and pathogenesis. In this review, we discuss a distinct role(s) of GLI proteins in the process of tumorigenesis and host-pathogen interactions in the context of viral infection-associated malignancies and cancers due to other causes. Here, we emphasize the potential of the Hedgehog (HH) pathway targeting as a potential anti-cancer therapeutic approach, which in the future could also be tested in infection-associated fatalities.

The emerging role of SPOP protein in tumorigenesis and cancer therapy

The nuclear speckle-type pox virus and zinc finger (POZ) protein (SPOP), a representative substrate-recognition subunit of the cullin-RING E3 ligase, has been characterized to play a dual role in tumorigenesis and cancer progression. Numerous studies have determined that SPOP suppresses tumorigenesis in a variety of human malignancies such as prostate, lung, colon, gastric, and liver cancers. However, several studies revealed that SPOP exhibited oncogenic function in kidney cancer, suggesting that SPOP could exert its biological function in a cancer type-specific manner. The role of SPOP in thyroid, cervical, ovarian, bone and neurologic cancers has yet to be determined. In this review article, we describe the structure and regulation of SPOP in human cancer. Moreover, we highlight the critical role of SPOP in tumorigenesis based on three major categories: physiological evidence (animal models), pathological evidence (human cancer specimens) and biochemical evidence (downstream ubiquitin substrates). Furthermore, we note that SPOP could be a promising therapeutic target for cancer treatment.

The emerging role of SPOP protein in tumorigenesis and cancer therapy

The nuclear speckle-type pox virus and zinc finger (POZ) protein (SPOP), a representative substrate-recognition subunit of the cullin-RING E3 ligase, has been characterized to play a dual role in tumorigenesis and cancer progression. Numerous studies have determined that SPOP suppresses tumorigenesis in a variety of human malignancies such as prostate, lung, colon, gastric, and liver cancers. However, several studies revealed that SPOP exhibited oncogenic function in kidney cancer, suggesting that SPOP could exert its biological function in a cancer type-specific manner. The role of SPOP in thyroid, cervical, ovarian, bone and neurologic cancers has yet to be determined. In this review article, we describe the structure and regulation of SPOP in human cancer. Moreover, we highlight the critical role of SPOP in tumorigenesis based on three major categories: physiological evidence (animal models), pathological evidence (human cancer specimens) and biochemical evidence (downstream ubiquitin substrates). Furthermore, we note that SPOP could be a promising therapeutic target for cancer treatment.

The role of hedgehog signaling in gastric cancer: molecular mechanisms, clinical potential, and perspective

Patients with advanced gastric cancer usually have a poor prognosis and limited therapeutic options. Overcoming this challenge requires novel targets and effective drugs. The Hedgehog (Hh) signaling pathway plays a crucial role in the development of the gastrointestinal tract and maintenance of the physiologic function of the stomach. Aberrantly activated Hh signaling is implicated in carcinogenesis as well as maintenance of cancer stem cells. Somatic mutations in the components of Hh signaling (PTCH1 and SMO) have been shown to be a major cause of basal cell carcinoma, and dozens of Hh inhibitors have been developed. To date, two inhibitors (GDC-0449 and LDE225) have been approved by the U.S. Food and Drug Administration to treat basal cell carcinoma and medulloblastoma. Here, we review the role of the Hh signaling in the carcinogenesis and progression of gastric cancer and summarize recent findings on Hh inhibitors in gastric cancer. Hedgehog signaling is often aberrantly activated and plays an important role during inflammation and carcinogenesis of gastric epithelial cells. Further study of the precise mechanisms of Hh signaling in this disease is needed for the validation of therapeutic targets and evaluation of the clinical utility of Hh inhibitors for gastric cancer.

Prognostic value of mismatch repair deficiency in patients with advanced gastric cancer, treated by surgery and adjuvant 5-fluorouracil and leucovorin chemoradiotherapy

OBJECTIVE

The predictive value of mismatch repair protein deficiency (MMRD) for chemoradiotherapeutic outcome has rarely been reported in gastric cancer. This study investigated the clinical significance of MMRD as a prognostic factor for tumor recurrence, and as a predictor of response to adjuvant chemoradiotherapy in advanced gastric cancer patients.

METHODS

Between 1995 and 2008, tissue specimens of 881 patients who underwent radical gastrectomy for stage II and III gastric cancer were analyzed. MMRD was assessed using immunohistochemical stains for MLH1, PMS2, MSH2, and MSH6. Patients were divided into two groups according to adjuvant treatment: a 5-fluorouracil/leucovorin (FL) adjuvant chemoradiotherapy group and a surgery alone group. Disease-free survival (DFS) was compared between the two groups correlated to MMRD. Risk factors for tumor recurrence were analyzed using multivariate analysis.

RESULTS

Of the 881 gastric cancer patients, 88 (10.0%) exhibited MMRD and 398 (45.2%) patients received adjuvant FL chemoradiotherapy. The multivariate analysis revealed that MMRD was a good independent prognostic factor (hazard ratio, 0.572; 95% confidence interval, 0.370-0.883; P = 0.012). For stage III gastric cancer displaying mismatch repair protein proficiency (MMRP), adjuvant FL chemoradiotherapy after surgery resulted in better DFS than surgery alone (P = 0.001). Among the stage II gastric cancer patients, adjuvant FL chemoradiotherapy did not show survival benefit, regardless of MMRD.

CONCLUSION

MMRD is a good independent prognostic factor in advanced gastric cancer. Adjuvant FL chemoradiotherapy was beneficial in patients with stage III gastric cancer with MMRP but not in those with MMRD.

Identification and validation of a Hedgehog pathway-based 3-gene prognostic signature for gastric cancers

Developing prognostic factors for patients with gastric cancer (GC) is crucial for the accurate identification of subgroups with distinct clinical outcomes and the development of effective treatment strategies. The aim of this study was to determine novel gene expression signatures from the hedgehog (Hh) signaling pathway as predictors of risk with biological significance. The Cancer Genome Atlas (TCGA) GC (STAD) cohort was used as the training dataset to select for significant prognostic Hh genes. Three Hh genes, indian hedgehog (IHH), patched 1 (PTCH1) and smoothened frizzled class receptor (SMO), were identified to be significant prognostic factors. On this basis, a 3-Hh-gene set was constructed and the high-risk patients of the training cohort were distinguished against low-risk cases [hazard ratio (HR)=1.73, 95% confidence interval (CI)=1.26-2.39, P=0.00069]. Then the gene signature was externally validated in a combined dataset from Gene Expression Omnibus (n=631), and experimentally confirmed in an independent cohort of 126 clinical GC samples by immunohistochemistry (IHC). Validation in the combined GEO dataset yielded consistent results (HR=1.45, 95% CI=1.17-1.81, P=0.00068), and remained significant for stages I-III, HER2-positive and surgery alone subgroups. Subsequently, we further demonstrated that this mRNA-based gene set could be successfully transferred to an IHC-based signature in our local cohort (HR=2.04, 95% CI=1.09-3.82, P=0.02). In addition, this signature served as an independent prognostic indicator for overall survival in the multivariate Cox analysis (HR=2.133, 95% CI=1.110-4.099, P=0.02). In conclusion, we successfully generated a stable III-Hh-gene model with the ability to separate patients into prognostic subgroups, which may have notable biological importance and be easily utilized clinically.

Molecular classification of gastric cancer: Towards a pathway-driven targeted therapy

Gastric cancer (GC) is the third leading cause of cancer mortality worldwide. Although surgical resection is a potentially curative approach for localized cases of GC, most cases of GC are diagnosed in an advanced, non-curable stage and the response to traditional chemotherapy is limited. Fortunately, recent advances in our understanding of the molecular mechanisms that mediate GC hold great promise for the development of more effective treatment strategies. In this review, an overview of the morphological classification, current treatment approaches, and molecular alterations that have been characterized for GC are provided. In particular, the most recent molecular classification of GC and alterations identified in relevant signaling pathways, including ErbB, VEGF, PI3K/AKT/mTOR, and HGF/MET signaling pathways, are described, as well as inhibitors of these pathways. An overview of the completed and active clinical trials related to these signaling pathways are also summarized. Finally, insights regarding emerging stem cell pathways are described, and may provide additional novel markers for the development of therapeutic agents against GC. The development of more effective agents and the identification of biomarkers that can be used for the diagnosis, prognosis, and individualized therapy for GC patients, have the potential to improve the efficacy, safety, and cost-effectiveness for GC treatments.

The Prognostic Significance of the Hedgehog Signaling Pathway in Colorectal Cancer

Despite significant advances in the management of colorectal cancer (CRC) the identification of new prognostic biomarkers continues to be a challenge. Since its initial discovery, the role of the Hedgehog (Hh) signaling pathway in carcinogenesis has been extensively studied. We herein review and comment on the prognostic significance of the Hh signaling pathway in CRC. The differential expression of Hh pathway components between malignant and nonmalignant conditions as well as correlation of Hh activation markers with various clinicopathological parameters and the effect on disease-free survival, overall survival, and disease recurrence in patients with CRC is summarized and discussed. According to the studies reviewed herein the activation of the Hh pathway seems to be correlated with adverse clinicopathological features and worse survival. However, to date study results show significant variability with regard to the effect on outcomes. Such results need to be interpreted carefully and emphasize the need for further well designed studies to characterize the actual influence of the Hh pathway in CRC prognosis.

Hedgehog signaling pathway as a therapeutic target for ovarian cancer

Ovarian cancer is the most lethal cause of death among gynecological malignancies. Despite advancements in surgery and chemotherapy treatment strategies, the prognosis of ovarian cancer patients remains poor; a majority of patients relapse and eventually succumb to this disease. Therefore, novel therapeutic approaches to improve patient outcome are urgently needed. The hedgehog signaling pathway is vital for embryonic development and tissue homeostasis, and its deregulation is implicated in cancer cell growth, survival, differentiation, and metastasis. The critical role of hedgehog signaling in multiple biologic processes raises concerns about its potential therapeutic use in cancer. Consequently, many studies are focusing on hedgehog signaling as an attractive target in cancer treatment. In this review, we present an overview of the hedgehog pathway and its pathological aberrations in ovarian cancer. We also discuss inhibitors of the hedgehog signaling pathway that are currently being investigated in the laboratory and in early clinical trials; as well as the clinical challenges these inhibitors face.

A Systematic Comparison of Traditional and Multigene Panel Testing for Hereditary Breast and Ovarian Cancer Genes in More Than 1000 Patients

Gene panels for hereditary breast and ovarian cancer risk assessment are gaining acceptance, even though the clinical utility of these panels is not yet fully defined. Technical questions remain, however, about the performance and clinical interpretation of gene panels in comparison with traditional tests. We tested 1105 individuals using a 29-gene next-generation sequencing panel and observed 100% analytical concordance with traditional and reference data on >750 comparable variants. These 750 variants included technically challenging classes of sequence and copy number variation that together represent a significant fraction (13.4%) of the pathogenic variants observed. For BRCA1 and BRCA2, we also compared variant interpretations in traditional reports to those produced using only non-proprietary resources and following criteria based on recent (2015) guidelines. We observed 99.8% net report concordance, albeit with a slightly higher variant of uncertain significance rate. In 4.5% of BRCA-negative cases, we uncovered pathogenic variants in other genes, which appear clinically relevant. Previously unseen variants requiring interpretation accumulated rapidly, even after 1000 individuals had been tested. We conclude that next-generation sequencing panel testing can provide results highly comparable to traditional testing and can uncover potentially actionable findings that may be otherwise missed. Challenges remain for the broad adoption of panel tests, some of which will be addressed by the accumulation of large public databases of annotated clinical variants.

Hedgehog pathway aberrations and gastric cancer; evaluation of prognostic impact and exploration of therapeutic potentials

Gastric cancer is an important cause for mortality and morbidity worldwide; it lies in the fourt rank as a cause of cancer-related death in males and in the fifth rank of cancer-related death in women. The prognosis of advanced/metastatic gastric cancer cases looks poor with the majority of available therapeutics. Thus, novel therapeutic strategies in this setting have been considered a priority for leading cooperative oncology groups. Hedgehog(Hh) pathway aberrations have sparked particular interest as prognostic markers with data from multiple studies showing consistent evidence of a poor prognostic value of Gli over expression in gastric cancer while on the other hand the prognostic significance of Hh protein over expression (particularly SHH) was not consistent among different studies. This review article revises the prognostic and potential therapeutic opportunities in the targeting of hedgehog pathway in gastric cancer.

Autophagy is related to the hedgehog signaling pathway in human gastric adenocarcinoma: prognostic significance of Beclin-1 and Gli2 expression in human gastric adenocarcinoma

Beclin-1 induces autophagy, which is known to be involved in many physiopathological processes such as cell development, aging, stress response, immune response and cancer. Several studies showed that Beclin-1 expression is associated with several prognostic factors of gastric carcinomas. Recently, the connection between autophagy and the hedgehog (HH) signaling pathway has been studied. Here, we investigated the relationship between the autophagy and hedgehog (HH) signaling pathways in gastric adenocarcinoma. We evaluated Beclin-1 and Gli2 expression in 108 gastric adenocarcinoma tissues via immunohistochemical analysis, using a tissue microarray, in relation to survival and other prognostic factors. Our results show that increased Beclin-1 expression is correlated with favorable clinicopathological variables including histologic grade, tumor size, primary tumor (T) stage, lymph node metastasis, lymphatic invasion, neural invasion, and tumor recurrence. Furthermore, increased Gli-2 expression was correlated with several favorable clinicopathological variables including primary tumor (T) stage, lymphatic invasion, and tumor recurrence. Increased Beclin-1 expression was significantly correlated with increased Gli2. Univariate analyses for disease-free survival and overall survival revealed that the higher Beclin-1 and Gli2 expression group had a more favorable prognosis compared with the lower Beclin-1 and Gli2 expression group. Our results suggest that progressively increased Beclin-1 and Gli2 expression contributes to the inhibition of tumor growth and metastasis in gastric adenocarcinoma and Beclin-1 acts as a tumor suppressor by regulating the HH signaling pathway through Gli2 expression in gastric adenocarcinoma.

Clinical evaluation of a multiple-gene sequencing panel for hereditary cancer risk assessment

PURPOSE

Multiple-gene sequencing is entering practice, but its clinical value is unknown. We evaluated the performance of a customized germline-DNA sequencing panel for cancer-risk assessment in a representative clinical sample.

METHODS

Patients referred for clinical BRCA1/2 testing from 2002 to 2012 were invited to donate a research blood sample. Samples were frozen at -80° C, and DNA was extracted from them after 1 to 10 years. The entire coding region, exon-intron boundaries, and all known pathogenic variants in other regions were sequenced for 42 genes that had cancer risk associations. Potentially actionable results were disclosed to participants.

RESULTS

In total, 198 women participated in the study: 174 had breast cancer and 57 carried germline BRCA1/2 mutations. BRCA1/2 analysis was fully concordant with prior testing. Sixteen pathogenic variants were identified in ATM, BLM, CDH1, CDKN2A, MUTYH, MLH1, NBN, PRSS1, and SLX4 among 141 women without BRCA1/2 mutations. Fourteen participants carried 15 pathogenic variants, warranting a possible change in care; they were invited for targeted screening recommendations, enabling early detection and removal of a tubular adenoma by colonoscopy. Participants carried an average of 2.1 variants of uncertain significance among 42 genes.

CONCLUSION

Among women testing negative for BRCA1/2 mutations, multiple-gene sequencing identified 16 potentially pathogenic mutations in other genes (11.4%; 95% CI, 7.0% to 17.7%), of which 15 (10.6%; 95% CI, 6.5% to 16.9%) prompted consideration of a change in care, enabling early detection of a precancerous colon polyp. Additional studies are required to quantify the penetrance of identified mutations and determine clinical utility. However, these results suggest that multiple-gene sequencing may benefit appropriately selected patients.

Cancer stem cell-related signaling pathways in development of gastric cancer

Cancer stem cells are a subset of cancer cells with self-renewal and differentiation capacity. They play an important role in gastric carcinogenesis, proliferation, migration, invasion and metastasis and are involved in resistance to chemotherapy. Numerous studies indicate that stem cell-related signaling pathways (such as Wnt, Notch, Hedgehog, PI3K, and BMP) are activated in the occurrence and development of gastric cancer. Inhibition of tumor self-renewal-related signaling pathways can significantly improve the prognosis of patients with gastric cancer. In this paper we will review the roles of these cancer stem cell-related signaling pathways in gastric cancer.

Hedgehog related protein expression in breast cancer: gli-2 is associated with poor overall survival

Background

The hedgehog (Hh) signaling pathway is known to play a critical role in various malignancies, but its clinicopathologic role in breast cancer is yet to be established.

Methods

Tissue microarray blocks from 334 cases of breast cancer were prepared. The expression of six Hh signaling proteins including sonic hedgehog (Shh), patched (Ptch), smoothened (Smo), and the glioma-associated oncogene (Gli)-1, Gli-2, and Gli-3 were analyzed immunohistochemically.

Results

The expression of Hh signaling proteins was significantly correlated with some prognostic factors including the correlation of lymph node metastasis with the expression of Shh (p=0.001) and Ptch (p=0.064), the correlation of the stages with Shh and Gli-3 expression (p=0.007 and p=0.024, respectively), the correlation of the nuclear grade with the Smo (p=0.004) and Gli-3 (p=0.000), and the correlation of the histologic grade with the Ptch (p=0.016), Smo (p=0.007), and Gli-3 (p=0.000). The Shh, Ptch, Smo, Gli-1, and Gli-2 expression was significantly different between the phenotypes (p=0.000, p=0.001, p=0.004, p=0.039, and p=0.031, respectively). Gli-2 expression was correlated with a worse overall survival outcome (p=0.012).

Conclusions

Hh pathway activation is correlated with a more aggressive clinical behavior in breast carcinomas. The comparison of phenotypes suggested that the Hh pathway may be a useful therapeutic target for breast carcinoma. Patients with Gli-2 expression had a significantly lower overall survival rate and, therefore, it showed promise as a prognostic marker.