Impact of Sonic Hedgehog Pathway Expression on Outcome in HPV Negative Head and Neck Carcinoma Patients after Surgery and Adjuvant Radiotherapy

Mapping the intricacies of GLI1 in hedgehog signaling: A combined bioinformatics and clinical analysis in Head & Neck cancer in Western India

BACKGROUND

Activation of various cancer stem cell pathways are thought to be responsible for treatment failure and loco-regional recurrence in Head and Neck cancer. Hedgehog signaling, a major cancer stem signaling pathway plays a major role in relapse of disease. GLI1, a transcription activator, plays an important role in canonical/non-canonical activation of Hedgehog signaling.

METHODS

Data for H&N cancer patients were collected from The Cancer Genome Atlas- H&N Cancer (TCGA-HNSC). GLI1 co-expressed genes in TCGA-HNSC were then identified using cBioPortal and subjected to KEGG pathway analysis by DAVID tool. Network Analyzer and GeneMania plugins from CytoScape were used to identify hub genes and predict a probable pathway from the identified hub genes respectively. To confirm the hypothesis, real-time gene expression was carried out in 75 patients of head and neck cancer.

RESULTS

Significantly higher GLI1 expression was observed in tumor tissues of H&N cancer and it also showed worst overall survival. Using cBioPortal tool, 2345 genes were identified that were significantly co-expressed with GLI1. From which, 15 hub genes were identified through the Network Analyzer plugin in CytoScape. A probable pathway prediction based on hub genes showed the interconnected molecular mechanism and its role in non-canonical activation of Hedgehog pathway by altering the GLI1 activity. The expressions of SHH, GLI1 and AKT1 were significant with each other and were found to be significantly associated with Age, Lymph-Node status and Keratin.

CONCLUSION

The study emphasizes the critical role of the Hh pathway's activation modes in H&N cancer, particularly highlighting the non-canonical activation through GLI1 and AKT1. The identification of SHH, GLI1 and AKT1 as potential diagnostic biomarkers and their association with clinic-pathological parameters underscores their relevance in prognostication and treatment planning. Hh pathway activation through GLI1 and its cross-talk with various pathways opens up the possibility of newer treatment strategies and developing a panel of therapeutic targets in H&N cancer patients.

Advantages of the Combinatorial Molecular Targeted Therapy of Head and Neck Cancer-A Step before Anakoinosis-Based Personalized Treatment

The molecular initiators of Head and Heck Squamous Cell Carcinoma (HNSCC) are complex. Human Papillomavirus (HPV) infection is linked to an increasing number of HNSCC cases, but HPV-positive tumors generally have a good prognosis. External factors that promote the development of HPV-negative HNSCC include tobacco use, excessive alcohol consumption, and proinflammatory poor oral hygiene. On a molecular level, several events, including the well-known overexpression of epidermal growth factor receptors (EGFR) and related downstream signaling pathways, contribute to the development of HNSCC. Conventional chemotherapy is insufficient for many patients. Thus, molecular-based therapy for HNSCC offers patients a better chance at a cure. The first molecular target for therapy of HNSCC was EGFR, inhibited by monoclonal antibody cetuximab, but its use in monotherapy is insufficient and induces resistance. This article describes attempts at combinatorial molecular targeted therapy of HNSCC based on several molecular targets and exemplary drugs/drug candidates. The new concept of anakoinosis-based therapy, which means treatment that targets the intercellular and intracellular communication of cancer cells, is thought to be the way to improve the clinical outcome for HNSCC patients. The identification of a link between molecular targeted therapy and anakoinosis raises the potential for further progress in HPV-negative HNSCC therapy.

The Role of Hedgehog Signaling Pathway in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading malignancy worldwide, with a poor prognosis and limited treatment options. Molecularly targeted therapies for HNSCC are still lacking. However, recent reports provide novel insights about many molecular alterations in HNSCC that may be useful in future therapies. Therefore, it is necessary to identify new biomarkers that may provide a better prediction of the disease and promising targets for personalized therapy. The poor response of HNSCC to therapy is attributed to a small population of tumor cells called cancer stem cells (CSCs). Growing evidence indicates that the Hedgehog (HH) signaling pathway plays a crucial role in the development and maintenance of head and neck tissues. The HH pathway is normally involved in embryogenesis, stem cell renewal, and tissue regeneration. However, abnormal activation of the HH pathway is also associated with carcinogenesis and CSC regulation. Overactivation of the HH pathway was observed in several tumors, including basal cell carcinoma, that are successfully treated with HH inhibitors. However, clinical studies about HH pathways in HNSCC are still rare. In this review, we summarize the current knowledge and recent advances regarding the HH pathway in HNSCC and discuss its possible implications for prognosis and future therapy.

Targeted therapy for head and neck cancer: signaling pathways and clinical studies

Head and neck cancer (HNC) is malignant, genetically complex and difficult to treat and is the sixth most frequent cancer, with tobacco, alcohol and human papillomavirus being major risk factors. Based on epigenetic data, HNC is remarkably heterogeneous, and treatment remains challenging. There is a lack of significant improvement in survival and quality of life in patients with HNC. Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy. In addition, resistance to chemotherapy, radiotherapy and some targeted therapies is common. Therefore, it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients. Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies. A well understanding of the pathogenesis of HNC contributes to learning more about its inner association, which provides novel insight into the development of small molecule inhibitors. In this review, we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC, as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy, which may contribute to a more favorable prognosis of HNC. Targeted therapy in combination with other therapies and its limitations were also discussed.

Long-Term Swallowing Outcome and Dysphagia in Advanced Staged Head and Neck Squamous Cell Carcinomas after Radiotherapy

Objective: To evaluate the impact of radiotherapy (RT) on dysphagia and long-term swallowing outcome in patients with stage III and IV head and neck squamous cell carcinomas (HNSCCs). Material and Methods: Between 2005 and 2008, 189 patients with HNSCCs underwent primary or adjuvant RT in a curative setting. Long-term swallowing outcome was evaluated in 50 patients. Among them, 26 were further eligible for prospective analysis of long-term swallowing and dysphagia outcome. Medical charts were retrospectively reviewed regarding pre- and post-treatment dysphagia (3 months after last irradiation setting) as well as persisting long-term dysphagia (2019−2021). Results: Pre-treatment dysphagia was observed in 24 (48%) of 50 patients, particularly in oropharyngeal or hypopharyngeal stage III−IV tumors (OR 9.3; p = 0.003). Conversely, 46 patients (92%) complained about post-treatment dysphagic symptoms, which were more commonly seen in patients with positive neck nodes (OR 10.5; p = 0.037). The post-treatment dysphagia rate dropped from 92% to 24% (p < 0.001) during surveillance, which was significantly linked to xerostomia (OR 5.77; p = 0.019), dysgeusia (OR 9.9; p = 0.036) and free flap reconstruction (OR 6.1; p = 0.022). Conclusion: Pretreatment dysphagia is common in advanced stage HNSCCs and almost all patients complain about dysphagia at the end of RT. Importantly, applied RT protocols did not affect long-term dysphagia, which improves significantly in the majority of patients over time. Meeting Information: Preliminary results have been presented at the 65th Annual Meeting of the Austrian Society of Otorhinolaryngology, 22−26 September 2021, Austria.

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.

Anti-fungal drug itraconazole exerts anti-cancer effects in oral squamous cell carcinoma via suppressing Hedgehog pathway

AIMS

To investigate the therapeutic potential of itraconazole in oral squamous cell carcinoma (OSCC) and its molecular mechanism.

MATERIALS AND METHODS

The in vitro anti-cancer effects of itraconazole was determined by CCK-8 assay and colony formation assay. Transwell and wound healing assays were used to examine cell invasion and migration. The in vivo therapeutic efficacy of itraconazole was assessed by OSCC patient-derived xenograft (PDX) model. Western blot was performed to explore the anti-cancer mechanism.

KEY FINDINGS

Itraconazole inhibited cell proliferation and colony formation of OSCC cells in a time and concentration dependent manner; induced cell cycle arrest and apoptosis, as well as inhibited cell invasion and migration. In the OSCC PDX model, itraconazole impeded tumor growth, reduced Ki-67 expression and induced apoptosis. Itraconazole downregulated the protein expression of Hedgehog pathway to inhibit proliferation and migration of oral squamous cell carcinoma cells, which can be revised by recombinant human sonic hedgehog protein (rSHH).

SIGNIFICANCE

Itraconazole showed anti-cancer effects on OSCC via inhibiting the Hedgehog pathway.

Widespread expression of Sonic hedgehog (Shh) and Nrf2 in patients treated with cisplatin predicts outcome in resected tumors and are potential therapeutic targets for HPV-negative head and neck cancer

Background:

Sonic hedgehog (Shh) and Nrf2 play a critical role in chemotherapeutic resistance. These two genes have been found to be dysregulated in head and neck squamous cell carcinomas (HNSCC). The purpose of this study was to analyze the expression, function and clinical prognostic relationship of Shh and Nrf2 in HNSCC in the context of therapeutic resistance and cancer stem cells (CSCs).

Methods:

We analyzed a cohort of patients with HNSCC to identify potential therapeutic biomarkers correlating with overall survival (OS) as well as disease-free survival (DFS) from our own data and validated these results using The Cancer Genome Atlas dataset. Expression of Shh and Nrf2 was knocked down by siRNA and cell growth, sphere growth and chemotherapeutic resistance were evaluated.

Results:

Widespread abundant expression of Shh and Nrf2 proteins were associated with shorter OS and DFS. The combination of Shh and Nrf2 expression levels was found to be a significant predictor of patient DFS. The tumor stromal index was correlated with Shh expression and inversely associated with shorter OS and DFS. Inhibition of Shh by siRNA or cyclopamine resulted in the attenuation of resistant CSC self-renewal, invasion, clonogenic growth and re-sensitization to the chemotherapeutic agents. Concomitant upregulation of Shh and Nrf2 proved to be an independent predictor of poor OS and DFS in patients with HNSCC.

Conclusions:

These findings suggest that Shh and Nrf2 could serve as therapeutic targets as well as promising dual prognostic therapeutic biomarkers for HNSCC.

Hedgehog pathway proteins SMO and GLI expression as prognostic markers in head and neck squamous cell carcinoma

Aims

Because the hedgehog signalling pathway plays a major role in many types of cancer and can nowadays be targeted by specific compounds, we aimed to investigate the role of this pathway in squamous cell carcinoma of the head and neck.

Methods and results

Ninety‐eight treatment‐naive head and neck cancer specimens were immunohistologically stained for SMO, GLI‐1, p53 and p16 expression and correlated with clinicopathological factors. Immunoreactivity for SMO and GLI‐1 was found in 20 (20.4%) and 52 (53.1%) cases of tumours, respectively. SMO expression correlated with GLI‐1 expression (ρ = 0.258, P = 0.010) in univariate and multivariate analysis (P = 0.007, t = 2.81). In univariate analysis, high SMO expression was associated with shorter overall survival (HR = 0.56; 95% CI = 0.32–0.98; P = 0.044) and disease‐free survival (HR = 0.53; 95% CI = 0.30–0.95; P = 0.034). In multivariate cox regression analysis SMO expression showed a trend towards an independent predictor for shorter overall survival (HR = 0.57; 95% CI = 0.30–1.05; P = 0.072) and disease‐free survival (HR = 0.53; 95% CI = 0.28–1.02; P = 0.056). In head and neck cancer patients with low tumour p16 expression, SMO expression was an independent factor for overall survival (HR = 0.49; 95% CI = 0.24–0.98; P = 0.043) and disease‐free survival (HR = 0.45; 95% CI = 0.22‐0.96; P = 0.037).

Conclusion

Although it needs to be confirmed in larger cohorts, our results suggest that targeting SMO might be a potentially therapeutic option in patients with head and neck cancer. In line, molecular pathological analyses including mutation analysis in the hedgehog pathway might point to additional therapeutic leads.

Upstream Hedgehog signaling components are exported in exosomes of cervical cancer cell lines

AIM

To investigate export of Hedgehog pathway (Hh) proteins Patched1, Smoothened, Sonic hedgehog and Indian hedgehog in cervical cancer cell line (CaCx) exosomes.

METHODS

Exosomes were isolated and characterized by Western blotting, scanning electron microscopy and in a colorimetric assay. Nucleic acids (RNA, DNA) and protein content of exosomes were analyzed. Hh pathway proteins in exosomes were detected using Western blotting.

RESULTS

CaCx secrete bio-macromolecule (DNA, RNA and proteins) enriched exosomes. CaCx exosomes contained higher amount of RNA with respect to DNA. CaCx preferentially exported Hh proteins (Patched1, Smoothened,  Sonic hedgehog, Indian hedgehog) in their exosomes. Cellular uptake assay revealed rapid internalization of CaCx exosomes in human umbilical vein endothelial cells.

CONCLUSION

Our study showed that Hh proteins are exported in CaCx exosomes.

Hedgehog Signaling in Lung Cancer: From Oncogenesis to Cancer Treatment Resistance

Hedgehog signaling pathway is physiologically activated during embryogenesis, especially in lung development. It is also reactivated in many solid tumors. In lung cancer, Hedgehog pathway is closely associated with cancer stem cells (CSCs). Recent works have shown that CSCs produced a full-length Sonic Hedgehog (Shh) protein, with paracrine activity and induction of tumor development. Hedgehog pathway is also involved in tumor drug resistance in lung cancer, as cytotoxic chemotherapy, radiotherapy, and targeted therapies. This review proposes to describe the activation mechanisms of Hedgehog pathway in lung cancer, the clinical implications for overcoming drug resistance, and the perspectives for further research.

Impact of anatomic origin of primary squamous cell carcinomas of the nasal cavity and ethmoidal sinus on clinical outcome

PURPOSE

Since squamous cell carcinomas (SCCs) of the nasoethmoidal complex are rare and aggressive malignancies, the purpose of this study was to evaluate whether anatomic subsites of SCCs of the nasal cavity and ethmoid sinuses affect clinical outcome.

METHODS

We retrospectively analyzed data from 47 patients with primary SCCs of the nasal cavity and ethmoid sinuses who were treated at the Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, between 1993 and 2018. The impact of anatomic subsites of nasoethmoidal SCCs was evaluated with respect to tumor and nodal classification, disease-free survival (DFS) and disease-specific survival (DSS).

RESULTS

Of the 47 cases, 17 SCCs (36.2%) originated from lateral nasal wall followed by 13 (27.7%) tumors of the edge of naris to mucocutaneous junction, 11 (23.4%) SCCs of the nasal septum, 3 tumors of the nasal floor (6.4%) and 3 SCCs of the ethmoid sinuses (6.4%), respectively. SCCs of the nasal septum were associated with significantly higher rates of neck node metastasis (p = 0.007), which represented a significantly worse prognostic factor for DSS (HR 7.87; p < 0.001). Moreover, advanced tumor stage (HR 5.38; p = 0.014) and tumor origin of nasal septum (HR 4.05; p = 0.025) were also significantly worse prognostic factors for DSS. Fourteen patients (29.8%) developed recurrent disease, including eight local (17.0%), five regional (10.6%) and one distant (2.1%) recurrence. Elective neck dissection (ND) was associated with lower (0 vs. 20.0%) but not significantly different regional and distant DFS (p = 0.075).

CONCLUSION

Anatomic origin of nasal SCC has significant impact on clinical outcome. SCCs of the nasal septum were associated with higher rates of positive neck nodes and worse outcome.

Intragenic DNA methylation of PITX1 and the adjacent long non-coding RNA C5orf66-AS1 are prognostic biomarkers in patients with head and neck squamous cell carcinomas

Background

Patients with squamous cell cancer of the head and neck region (HNSCC) are at risk for disease recurrence and metastases, even after initial successful therapy. A tissue-based biomarker could be beneficial to guide treatment as well as post-treatment surveillance. Gene methylation status has been recently identified as powerful prognostic biomarker in HNSCC. We therefore evaluated the methylation status of the homeobox gene PITX1 and the adjacent long intergenic non-coding RNA (lincRNA) C5orf66-AS1 in publicly available datasets.

Methods

Gene methylation and expression data from 528 patients with HNSCC included in The Cancer Genome Atlas (TCGA, there obtained by using the Infinium HumanMethylation450 BeadChip Kit) were evaluated and methylation and expression levels of PITX1 and lincRNA C5orf66-AS1 was correlated with overall survival and other parameters. Thus, ten beads targeting PITX1 exon 3 and three beads targeting lincRNA C5orf66-AS1 were identified as significant candidates. The mean methylation of these beads was used for further correlation and the median was employed for dichotomization.

Results

Both PITX1 exon 3 and lincRNA C5orf66-AS1 were significantly higher methylated in tumor tissue than in normal adjacent tissue (NAT) (PITX1 exon 3: tumor tissue 58.1%, NAT: 31.7%, p<0.001; lincRNA C5orf66-AS1: tumor tissue: 27.4%, NAT: 18.9%, p<0.001). In a univariate analysis, hypermethylation of both loci was significantly associated with the risk of death (univariate: exon 3: Hazard ratio (HR): 4.97 [1.78–16.71], p = 0.010, lincRNA C5orf66-AS1: Hazard ratio (HR): 12.23 [3.01–49.74], p<0.001). PITX1 exon 3 and lincRNA C5orf66-AS1 methylation was also significantly correlated with tumor localization, T category, human papilloma virus (HPV)-negative and p16-negative tumors and tumor grade. Kaplan-Meier analysis showed, that lincRNA C5orf66-AS1 hypomethylation was significantly associated with overall survival (p = 0.001) in the entire cohort as well in a subgroup of HPV-negative tumors (p = 0.003) and in patients with laryngeal tumors (p = 0.022).

Conclusion

Methylation status of PITX1 and even more so of lincRNA C5orf66-AS1 is a promising prognostic biomarker in HNSCC, in particular for HPV-negative patients. Further prospective evaluation is warranted.