Plasma ctDNA Monitoring of a PTCH1-Mutant Metastatic Adult Medulloblastoma Showing a Durable Benefit With Vismodegib.

Adult medulloblastoma (MB) is a rare disease affecting 0.6 persons per million adults over 19 years of age. The SHH-activated/TP53-wild type is the most common subtype, accounting for 60% of adult MBs, being characterized by mutations in PTCH1, SMO, or the TERT promoter. Several small studies demonstrate objective but short-lived responses to SMO inhibitors such as vismodegib or sonidegib. Like other oncogene-addicted solid tumors, detection of the corresponding drivers through liquid biopsy could aid in the molecular diagnosis and monitoring of the disease through less invasive procedures. However, most studies have only evaluated cerebrospinal fluid as the ctDNA reservoir, and very limited evidence exists on the role of liquid biopsy in plasma in patients with primary central nervous system tumors, including MB. We present the case of a 26-year-old patient with a recurrent MB, in which next-generation sequencing (FoundationOne CDx) revealed a mutation in PTCH1, allowing the patient to be treated with vismodegib in second line, resulting in a durable benefit lasting for 1 year. Using an in-house digital PCR probe, the PTCH1 mutation could be tracked in ctDNA during treatment with first-line chemotherapy and while on treatment with vismodegib, demonstrating a precise correlation with the radiological and clinical behavior of the disease.

Hedgehog Inhibitors Beyond Clinical Complete Response in Basal Cell Carcinoma: Should I Stop or Should I Go?

INTRODUCTION: In advanced basal cell carcinoma (BCC), the issue of whether Hedgehog inhibitors (HHIs) should be stopped or not after clinical complete response (cCR) achievement remains an unmet clinical need. MATERIALS AND METHODS: We conducted a retrospective, multicenter study across 7 Italian dermato-oncology units including patients with BCC who continued vismodegib after cCR between 2012 and 2019. We assessed the relationship between the duration of vismodegib intake (days to cCR [DTCR], days to stop after cCR [DTS], total treatment days [TTD]), and disease-free survival (DFS). Reasons to stop vismodegib were (R1) toxicity and (R2) disease recurrence. The relationship between DTCR, DTS, TTD, and DFS in the whole population and in R1 subgroup was assessed by Pearson's correlation coefficient (P < .05) and Bayesian statistics (BF10). RESULTS: Sixty-eight BCC patients with a median (m) age of 75.5 years (39-100) were included. Most patients were male (N = 43, 63%), without Gorlin syndrome (N = 56, 82%) and with head and neck area as primary site (N = 51, 75%). After cCR, out of 68 patients, 90% (N = 61/68) discontinued vismodegib: 82% (N = 50/61) due to toxicity (R1), and 18% (N = 11/61) due to recurrence (R2). Conversely, 10% (N = 7/68) continued vismodegib until last follow-up. In the whole population (N = 68), cCR was achieved with a mDTCR of 180.50 days. DFS showed a significant correlation with DTS (P < .01, BF10 = 39.2) and TTD (P < .01, BF10 = 35566), while it was not correlated to DTCR (BF10 < 0.1). The analysis of R1 subgroup (N = 50) confirmed these results. DFS correlated with DTS in all recurrent patients (N = 38, r = 0.44, P < .01) and in the recurrent patients who stopped vismodegib for toxicity (N = 26, r = 0.665, P < .01). DFS was longer when vismodegib was maintained for >2 months after cCR (mDFS > 2 months, N = 54 vs. ≤ 2 months, N = 14: 470 vs. 175 d, P < .01). CONCLUSIONS: Our retrospective results suggest that HHIs should be continued after cCR to improve DFS in BCC.

Oral Hedgehog Inhibitor, Vismodegib, for Locally Advanced Periorbital and Orbital Basal Cell Carcinoma: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the efficacy and safety of oral vismodegib (Erivedge; Genentech) in the management of locally advanced orbital and periorbital basal cell carcinoma (BCC). METHODS: A literature search was conducted last in September 2023 in the PubMed database for English language original research that evaluated the effect of oral vismodegib on orbital and periorbital BCC. Sixty articles were identified and 16 met the inclusion criteria. RESULTS: Most studies demonstrated high response rates, with up to 100% of patients responding to the medication in individual studies and initial complete regression occurring in up to 88% of patients. Vismodegib treatment resulted in significant reductions in tumor volume, resulting in globe preservation for most patients. However, in 12% of patients, the response was partial. Recurrences also occurred with substantial frequency, even after an initial complete response. As such, up to 79.4% of patients required surgical intervention, and up to 23% of patients still required exenteration. Use of these agents resulted in reductions in tumor volume that may delay or prevent the need for exenteration in some, but not all, patients. Importantly, molecular analysis of tissue excised after vismodegib therapy revealed persistent tumor in all patients, with frequent accumulation of mutations that may confer resistance to further hedgehog inhibitor therapy. Although most adverse events were rated as level I or II, side effects were common, with up to 100% of patients in studies experiencing at least 1 event. Muscle cramps, alopecia, weight loss, fatigue, and dysgeusia were the most common adverse events, and several patients discontinued therapy because of them. Furthermore, 1 patient died of sepsis that may have resulted from the therapy. CONCLUSIONS: Although level I and II evidence are lacking, most studies indicate a benefit from the use of oral vismodegib to treat orbital and periorbital BCC tumor volume. However, patients should be cautioned about the adverse side effects of treatment and the persistence of tumor cells with mutations that may cause long-term resistance. Use of vismodegib as short-term neoadjuvant therapy may be effective in shrinking tumor volume to reduce surgical morbidity while reducing the frequency and severity of side effects. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Beyond cyclopamine: Targeting Hedgehog signaling for cancer intervention.

Hedgehog (Hh) signaling plays a significant role in embryogenesis and several physiological processes, such as wound healing and organ homeostasis. In a pathological setting, it is associated with oncogenesis and is responsible for disease progression and poor clinical outcomes. Hedgehog signaling mediates downstream actions via Glioma Associated Oncogene Homolog (GLI) transcription factors. Inhibiting Hh signaling is an important oncological strategy in which inhibitors of the ligands SMO or GLI have been looked at. This review briefly narrates the Hh ligands, signal transduction, the target genes involved and comprehensively describes the numerous inhibitors that have been evaluated for use in various neoplastic settings.

SHH induces macrophage oxidative phosphorylation and efferocytosis to promote scar formation.

Excessive scar formation such as hypertrophic scars and keloids, resulting from trauma or surgical procedures, present a widespread concern for causing disfigurement, discomfort, and functional limitations. Macrophages play pivotal roles in maintaining tissue homeostasis, orchestrating tissue development, repair, and immune responses, and its transition of function and phenotype plays a critical role in regulating the balance between inflammation and tissue regeneration, which is central to cutaneous scar formation. Recent evidence suggests the involvement of Sonic Hedgehog (SHH) in the induction of anti-inflammatory M2-like macrophage phenotypes within tumor microenvironments. In our study, we observed increased SHH expression in human hypertrophic scars, prompting an investigation into its influence on macrophage polarization, efferocytosis, and cutaneous scar formation. Our findings reveal that SHH can enhance oxidative phosphorylation (OXPHOS) in macrophages, augment macrophage efferocytosis, and promote M2 polarization, finally contributing to the progression of cutaneous scar formation. Notably, targeting SHH signaling with vismodegib exhibited promising potential in mitigating scar formation by reversing the effects of enhanced OXPHOS and M2 polarization in macrophages. In conclusion, this study underscores the critical roles of macrophage metabolism, particularly OXPHOS, efferocytosis and SHH signaling in cutaneous scar formation. Understanding these mechanisms provides new avenues for potential interventions and scar prevention strategies.

Non-canonical non-genomic morphogen signaling in anucleate platelets: a critical determinant of prothrombotic function in circulation.

Circulating platelets derived from bone marrow megakaryocytes play a central role in thrombosis and hemostasis. Despite being anucleate, platelets express several proteins known to have nuclear niche. These include transcription factors and steroid receptors whose non-genomic functions are being elucidated in platelets. Quite remarkably, components of some of the best-studied morphogen pathways, namely Notch, Sonic Hedgehog (Shh), and Wnt have also been described in recent years in platelets, which regulate platelet function in the context of thrombosis as well as influence their survival. Shh and Notch pathways in stimulated platelets establish feed-forward loops of autocrine/juxtacrine/paracrine non-canonical signaling that helps perpetuate thrombosis. On the other hand, non-canonical Wnt signaling is part of a negative feedback loop for restricting platelet activation and possibly limiting thrombus growth. The present review will provide an overview of these signaling pathways in general. We will then briefly discuss the non-genomic roles of transcription factors and steroid receptors in platelet activation. This will be followed by an elaborate description of morphogen signaling in platelets with a focus on their bearing on platelet activation leading to hemostasis and thrombosis as well as their potential for therapeutic targeting in thrombotic disorders.

Oral smoothened inhibitors for Gorlin syndrome: A clinical review.

Although smoothened inhibitors (SMOi) have demonstrated efficacy in the management of basal cell carcinoma, no guidelines are available on how to utilize SMOi in the treatment of Gorlin syndrome (GS). This review's objective is to assess the clinical response to SMOi in GS, provide practical guidance for clinicians, and identify areas for future research. Through comprehensive searches of previous publications and expert opinion, this review demonstrates that intermittent dosing of SMOi and daily dosing have similar efficacy. While the adverse events of SMOi may result in their discontinuation during treatment of GS, intermittent dosing may improve compliance.

Laser-assisted topical delivery of vismodegib reduces hedgehog gene expression in human basal cell carcinomas in vivo.

BACKGROUND: Systemically delivered hedgehog inhibitors including vismodegib and sonidegib are widely used to treat basal cell carcinomas (BCCs). Ablative fractional laser (AFL)-assisted topical delivery of vismodegib has been demonstrated in preclinical studies. The aim of this explorative clinical study was to evaluate intratumoral vismodegib concentrations and effect on hedgehog pathway gene expression following AFL-assisted topical vismodegib delivery to BCCs. METHODS: In an open-label clinical trial, 16 nodular BCCs (in n = 9 patients) received one application of CO2 -AFL (40 mJ/microbeam, 10% density) followed by topical vismodegib emulsion. After 3-4 days, vismodegib concentrations in tumor biopsies (n = 15) and plasma were analyzed and compared with samples from patients receiving oral treatment (n = 3). GLI1, GLI2, PTCH1, and PTCH2 expression was determined by quantitative polymerase chain reaction (n = 7) and GLI1 additionally by in situ hybridization (n = 3). RESULTS: Following AFL-assisted topical administration, vismodegib was detected in 14/15 BCCs and reached a median concentration of 6.2 µmol/L, which compared to concentrations in BCC tissue from patients receiving oral vismodegib (9.5 µmol/L, n = 3, p = 0.8588). Topical vismodegib reduced intratumoral GLI1 expression by 51%, GLI2 by 55%, PTCH1 and PTCH2 each by 73% (p ≤ 0.0304) regardless of vismodegib concentrations (p ≥ 0.3164). In situ hybridization demonstrated that GLI1 expression was restricted to tumor tissue and downregulated in response to vismodegib exposure. CONCLUSION: A single AFL-assisted topical application of vismodegib resulted in clinically relevant intratumoral drug concentrations and significant reductions in hedgehog pathway gene expressions.

Vismodegib in Gorlin-Goltz syndrome: A systematic review.

Treatment with Hedgehog Inhibitors in Gorlin-Goltz syndrome (GGS) yields favourable objective clinical responses, yet secondary resistance and class-related toxicity restrict treatment duration. This study aims to review current data on GGS patients undergoing vismodegib therapy, focusing on treatment duration, clinical outcomes and schedule modifications. A systematic search of the PubMed database was conducted for English articles from 1993 to 2023, identifying 31 papers suitable for inclusion. A total of 351 patients, with a mean age of 52 years, were analysed. The average treatment duration was 9.3 months for patients who discontinued treatment, and 25.1 months for those who continued vismodegib at the time this study was published. Vismodegib achieved a complete response rate of 44%. Treatment interruption predominantly occurred due to side effects (69.1%) and secondary resistance (9.1%). The use of alternative regimens, although not compromising efficacy, may enhance treatment compliance. Further investigations are warranted to ascertain the optimal treatment regimen and timeline for GGS patients. Schedule modifications offer promise in ameliorating side effects and facilitating long-term treatment.

Treatment of locally advanced and metastatic basosquamous carcinoma, navigating among sonic hedgehog pathway inhibitors, immune checkpoint inhibitors, chemotherapy, and radiotherapy: A case series and literature review.

Locally advanced (laBSCs) and metastatic basosquamous carcinomas (mBSCs) represent a therapeutic challenge. By definition, these forms are not amenable to surgery or radiotherapy, but according to literature reports, sonic hedgehog pathway inhibitors (HHIs), anti-programmed death 1 receptor antibodies (anti-PD-1), and other treatment approaches involving chemotherapy, surgery, and radiotherapy have been used. This work features 5 real-life cases of advanced BSCs, treated at the Dermato-Oncology Unit of Trieste (Maggiore Hospital, University of Trieste). In addition, a review of the current treatment options reported in the literature for laBSC and mBSC is provided, collecting a total of 17 patients. According to these preliminary data, HHIs such as sonidegib and vismodegib could represent a safe and effective first line of treatment, while the anti-PD-1 cemiplimab may be useful as a second-line option. Chemotherapy and combined approaches involving surgery and radiotherapy have been also reported to be suitable in some patients.

Ablative fractional laser treatment reduces hedgehog pathway gene expression in murine basal cell carcinomas.

This study aimed to investigate the impact of ablative fractional laser (AFL) on hedgehog pathway gene expression in murine microscopic basal cell carcinomas (BCCs) and compare these results to the effect of topical treatment with vismodegib, an FDA-approved hedgehog inhibitor. In 25 mice, 1 cm2 skin test sites (n = 44) containing microscopic BCCs were exposed to one of three interventions: a single CO2 AFL treatment (1 pulse, 40 mJ/microbeam, wavelength 10.6 µm, 5% density, pulse rate 250 Hz, n = 12), eight topical vismodegib treatments (3.8 mg/mL, n = 8), or combination of AFL and vismodegib treatments (n = 9). Untreated controls were included for comparison (n = 15). After 4 days, skin samples were analyzed for hedgehog gene expression (Gli1, Gli2, and Ptch1) by qPCR and vismodegib concentrations by liquid chromatography mass spectrometry (data analyzed with two-tailed t-tests and linear regression). A single treatment with AFL monotherapy significantly reduced hedgehog gene expression compared to untreated controls (Gli1 72.4% reduction, p = 0.003; Gli2 55.2%, p = 0.010; Ptch1 70.9%, p < 0.001). Vismodegib treatment also reduced hedgehog gene expression (Gli1 91.6%; Gli2 83.3%; Ptch1 83.0%), significantly surpassing AFL monotherapy for two out of three genes (Gli1, p = 0.017; Gli2, p = 0.007; Ptch1, p = 0.15). AFL and vismodegib combination mirrored the effects of vismodegib monotherapy (Gli1, p = 0.424; Gli2, p = 0.289; Ptch1, p = 0.593), possibly due to comparable cutaneous vismodegib concentrations (mean ± SD, vismodegib monotherapy 850 ± 475 µmol/L; combination 1036 ± 824 µmol/L; p = 0.573). In conclusion, a single AFL treatment significantly reduced hedgehog gene expression in murine BCCs mimicking the effects of eight topical applications of vismodegib. Further studies are needed to assess whether AFL can be utilized for BCC treatment, either as monotherapy or in combination with other drugs.

A novel indole derivative, 2-{3-[1-(benzylsulfonyl)piperidin-4-yl]-2-methyl-1H-indol-1-yl}-1-(pyrrolidin-1-yl)ethenone, suppresses hedgehog signaling and drug-resistant tumor growth.

The Hedgehog (Hh) signaling pathway plays important roles in various physiological functions. Several malignancies, such as basal cell carcinoma (BCC) and medulloblastoma (MB), have been linked to the aberrant activation of Hh signaling. Although therapeutic drugs have been developed to inhibit Hh pathway-dependent cancer growth, drug resistance remains a major obstacle in cancer treatment. Here, we show that the newly identified, 2-{3-[1-(benzylsulfonyl)-1,2,3,6-tetrahydropyridin-4-yl]-2-methyl-1H-indol-1-yl}-1-(pyrrolidin-1-yl)ethenone analog (LKD1214) exhibits comparable potency to vismodegib in suppressing the Hh pathway activation. LKD1214 represses Smoothened (SMO) activity by blocking its ciliary translocation. Interestingly, we also identified that it has a distinctive binding interface with SMO compared with other SMO-regulating chemicals. Notably, it maintains an inhibitory activity against the SmoD477H mutant, as observed in a patient with vismodegib-resistant BCC. Furthermore, LKD1214 inhibits tumor growth in the mouse model of MB. Collectively, these findings suggest that LKD1214 has the therapeutic potential to overcome drug-resistance in Hh-dependent cancers.

HPV16 infection promotes the malignant transformation of the esophagus and progression of esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) may be correlated with HPV infection, and the mechanism underlying the ESCC formation induced by HPV16 infection remains elusive. Here, we overexpressed HPV16 E6 and E7 and coordinated the overexpression of these two genes in EPC2 and ESCC cells. We found that E7 and coordinated expression of E6 and E7 promoted the proliferation of EPC2 cells, and upregulation of shh was responsible for cell proliferation since the use of vismodegib led to the failure of organoid formation. Meanwhile, overexpression of E6 and E7 in ESCC cells promoted cell proliferation, migration, and invasion in vitro. Importantly, E6 and E7 coordinately increased the capability of tumor growth in nude mice, while vismodegib slowed the growth of tumors in NCG mice. Moreover, a series of genes and proteins changed in cell lines after overexpression of the E6 and E7 genes, the potential biological processes and pathways were systematically analyzed using a bioinformatics assay. Together, these findings suggest that the activation of the hedgehog pathway induced by HPV16 infection may initially transform basal cells in the esophagus and promote following malignant processes in ESCC cells. The application of hedgehog inhibitors may represent a therapeutic avenue for ESCC treatment.

Real-World Experience with Vismodegib on Advanced and Multiple BCCs: Data from the RELIVIS Study.

BACKGROUND: Vismodegib is approved for advanced cases of basal cell carcinomas not amenable to surgery or radiotherapy. Large studies on the use of vismodegib in clinical practice are scarce. OBJECTIVES: The main objective of the study was to analyse the evolution and therapeutic management of relapses and lack of response in patients who had received vismodegib for locally advanced and/or multiple basal cell carcinomas in a real-life multicentre setting. METHODS: This nationwide retrospective study collected data on patients treated with vismodegib in 15 specialized centres. We included patients who first received vismodegib until intolerable toxicity, maximum response, or progressive disease. Exploratory research variables referred to patient and tumour characteristics, vismodegib effectiveness and safety, relapse rate and management, and mortality. A multivariable logistic regression model was used to identify predictors of complete clinical response. RESULTS: 133 patients with advanced BCC were included in the registry. The objective response rate (ORR) was 77.5% and nearly half of the patients (45.9%) achieved complete remission. Long-term information and detailed information of subsequent treatments after a regime of vismodegib was available for 115 patients. Only 34% of the patients in this group were subsequently treated with other therapies or vismodegib rechallenge. Sixty-nine percent of the patients who had shown a complete remission with vismodegib remained free of recurrence while 30.7% relapsed. Almost half of the patients who received additional therapies after the first course of vismodegib achieved complete tumour remission. Three and 2 out of 9 patients who were rechallenged with vismodegib achieved complete and partial responses, respectively, with an ORR of 55.5%. CONCLUSION: Our study confirms efficacy of vismodegib in routine clinical practice. The risk of recurrence after achieving complete response with vismodegib was lower than previous reports. Rechallenge with vismodegib is feasible and most patients responded to re-treatment.

Clinical Characteristics of an Italian Patient Population with Advanced BCC and Real-Life Evaluation of Hedgehog Pathway Inhibitor Safety and Effectiveness.

BACKGROUND: Advanced basal cell carcinoma (aBCC) represents a complex and clinically heterogeneous group of lesions for which curative surgery and/or radiotherapy is unlikely. Systemic therapy with hedgehog pathway inhibitors (HHIs) changed the treatment landscape for this complex patient population. OBJECTIVES: The aims of the present study are to describe the clinical characteristics of a real-life Italian cohort diagnosed with aBCC and to investigate effectiveness and safety of HHI. METHODS: A multicenter observational study was performed by twelve Italian centers in the period January 1, 2016 - October 15, 2022. Patients aged ≥18 years and diagnosed with aBCC (locally advanced [laBCC] and metastatic BCC [mBCC]) were eligible for the study. Methods for investigating tumor response to HHI included clinical and dermatoscopic evaluation, radiological imaging, and histopathology. For HHI safety assessment, therapy-related adverse events (AEs) were reported and graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. RESULTS: We enrolled 178 patients under treatment with HHI: 126 (70.8%) and 52 patients (29.2%) received sonidegib and vismodegib, respectively. Comprehensive data on HHI effectiveness and disease outcome were available for 132 (74.1%) of 178 patients: 129 patients had a diagnosis of laBCC (n = 84, sonidegib; n = 45, vismodegib) and 3 patients of mBCC (n = 2, vismodegib; n = 1, sonidegib, off-label). Objective response rate was 76.7% (95% confidence interval [CI]: 82.3-68.7) and 33.3% (95% CI: 88.2-1.7) for laBCC (complete response [CR]: 43/129; PR: 56/129) and mBCC (CR: 0/3; PR: 1/3), respectively. High-risk aBCC histopathological subtypes and occurrence of >2 therapy-related AEs were significantly associated with nonresponse to HHI therapy ([OR: 2.61; 95% CI: 1.09-6.05; p: 0.03] and [OR: 2.74; 95% CI: 1.03-7.9; p: 0.04]), respectively. Majority of our cohort (54.5%) developed at least 1 therapy-related AE, most of which were mild-moderate in severity. CONCLUSIONS: Our results demonstrate the effectiveness and safety profile of HHI and confirm the reproducibility of pivotal trial results in real-life clinical setting.

Vismodegib in Locally Advanced Basal Cell Carcinoma in Slovenia.

BACKGROUND: Vismodegib is a first-in-class inhibitor of the hedgehog pathway for treatment of locally advanced basal cell carcinoma (laBCC) and metastatic BCC. OBJECTIVES: The purpose of this study is to report outcomes of patients with laBCC, with basal cell carcinoma nevus syndrome (Gorlin Goltz syndrome [G-G Syn]) treated with vismodegib in routine clinical practice in Slovenia in 8.3-year period. METHODS: In this retrospective cohort study, we analyzed baseline characteristics, outcomes, and treatment-related adverse events from locally advanced BCC. The patients were divided into two cohorts: 39 laBCC or multiple BCC patients and 7 patients with G-G Syn who were treated with vismodegib from November 2012 till January 2021. RESULTS: During 100-month period, 46 patients were diagnosed with laBCC (26), multiple BCC (13), and G-G Syn (7), all inappropriate for surgery or radiotherapy. Baseline characteristics: median age was 72.8 years in laBCC + multiple BCC cohort and 47.4 years in G-G Syn cohort. The objective response rate was 80% in laBCC + multiple BCC and 86% in G-G Syn cohort. Disease control rate (DCR) was 95% in laBCC + multiple BCC and 100% in G-G Syn cohort. Median duration of treatment was 9.9 months (range: 1.5-43.1) in laBCC and multiple BCC cohort and 19.5 months (range: 3.6-94.1) in G-G Syn cohort. Majority of treatment-emergent adverse events (TEAEs) in laBCC or multiple BCC cohort were grade 1 or 2 (96%), only 4% of AEs were grade 3. Majority of TEAEs in G-G Syn cohort were also grade 1 or 2 (87%), 13% of AEs were grade 3. No grade 4 or 5 vismodegib-related AEs were reported. CONCLUSION: Vismodegib has shown meaningful efficacy with DCR from 95% to 100% in patients with laBCC, multiple BCC, and G-G Syn in Slovenia. TEAEs were successfully alleviated with multidisciplinary approach and early supportive care.

Combinations of PRI-724 Wnt/ß-Catenin Pathway Inhibitor with Vismodegib, Erlotinib, or HS-173 Synergistically Inhibit Head and Neck Squamous Cancer Cells.

The Wnt/ß-catenin, EGFR, and PI3K pathways frequently undergo upregulation in head and neck squamous carcinoma (HNSCC) cells. Moreover, the Wnt/ß-catenin pathway together with Hedgehog (Hh) signaling regulate the activity of cancer stem cells (CSCs). The aim of this study was to investigate the effects of the combinatorial use of the Wnt/ß-catenin and Hh pathway inhibitors on viability, cell cycle progression, apoptosis induction, cell migration, and expression of CSC markers in tongue (CAL 27) and hypopharynx (FaDu) cancer cells. Co-inhibition of Wnt signaling with EGFR or PI3K pathways was additionally tested. The cells were treated with selective inhibitors of signaling pathways: Wnt/ß-catenin (PRI-724), Hh (vismodegib), EGFR (erlotinib), and PI3K (HS-173). Cell viability was evaluated by the resazurin assay. Cell cycle progression and apoptosis induction were tested by flow cytometric analysis after staining with propidium iodide and Annexin V, respectively. Cell migration was detected by the scratch assay and CSC marker expression by the R-T PCR method. Mixtures of PRI-724 and vismodegib affected cell cycle distribution, greatly reduced cell migration, and downregulated the transcript level of CSC markers, especially POU5F1 encoding OCT4. Combinations of PRI-724 with erlotinib or HS-173 were more potent in inducing apoptosis.

Inhibition of Hedgehog Delays Liver Regeneration through Disrupting the Cell Cycle.

Liver regeneration is a complicated biological process orchestrated by various liver resident cells. Hepatic cell proliferation and reconstruction of the hepatic architecture involve multiple signaling pathways. It has been reported that the Hh signal is involved in liver regeneration. However, the signal transduction pathways and cell types involved are ill studied. This study aimed to investigate hedgehog signal response cell types and the specific molecular mechanism involved in the process of liver regeneration. Partial hepatectomy (PH) of 70% was performed on ICR (Institute of Cancer Research) mice to study the process of liver regeneration. We found that the hedgehog signal was activated significantly after PH, including hedgehog ligands, receptors and intracellular signaling molecules. Ligand signals were mainly expressed in bile duct cells and non-parenchymal hepatic cells, while receptors were expressed in hepatocytes and some non-parenchymal cells. Inhibition of the hedgehog signal treated with vismodegib reduced the liver regeneration rate after partial hepatectomy, including inhibition of hepatic cell proliferation by decreasing Cyclin D expression and disturbing the cell cycle through the accumulation of Cyclin B. The current study reveals the important role of the hedgehog signal and its participation in the regulation of hepatic cell proliferation and the cell cycle during liver regeneration. It provides new insight into the recovery of the liver after liver resection.

Brain-derived neurotrophic factor overexpression in taste buds diminishes chemotherapy induced taste loss.

Vismodegib is used in patients suffering from advanced basal cell carcinoma (BCC), but 100% of the patients taking it report dysgeusia and 50% discontinue the treatment. Treatment with neurotrophic factors can stimulate neuronal survival and functional improvement in injured organs. Here, we analysed novel transgenic mouse lines in which brain-derived neurotrophic factor (BDNF) is overexpressed in taste buds, to examine whether higher levels of BDNF would reduce or prevent negative side effects of vismodegib in the taste system. BDNF plays crucial roles for development, target innervation, and survival of gustatory neurons and taste buds. The behavioural test in this study showed that vehicle-treated wild-type mice prefered 10 mM sucrose over water, whereas vismodegib treatment in wild-type mice caused total taste loss. Gustducin-BDNF mice had a significantly increased preference for low concentration of sucrose solution over water compared to wild-type mice, and most importantly the transgenic mice were able to detect low concentrations of sucrose following vismodegib treatment. We evaluated taste cell morphology, identity, innervation and proliferation using immunohistochemistry. All drug-treated mice exhibited deficits, but because of a possible functional upcycled priming of the peripheral gustatory system, GB mice demonstrated better morphological preservation of the peripheral gustatory system. Our study indicates that overexpression of BDNF in taste buds plays a role in preventing degeneration of taste buds. Counteracting the negative side effects of vismodegib treatment might improve compliance and achieve better outcome in patients suffering from advanced BCC.

Advanced basal cell carcinoma: What dermatologists need to know about treatment.

The treatment of advanced basal cell carcinoma (BCC) often requires therapies beyond local surgical excision or radiation due to the invasiveness of the tumor. Historically, cytotoxic chemotherapy was used to treat advanced BCC, but with limited data, no standard regimens were established. The discovery of cyclopamine, a natural inhibitor in the Hedgehog pathway, led to the development of the 2 currently approved Hedgehog inhibitors, vismodegib and sonidegib. Both agents are indicated for locally advanced BCC, while vismodegib is also indicated for metastatic BCC. In patients who progress on hedgehog inhibitors or cannot tolerate hedgehog inhibitors, the programmed cell death protein 1 inhibitor cemiplimab can be used to treat locally advanced or metastatic disease. Complex cases of locally advanced or metastatic BCC may be best discussed through a multidisciplinary approach in order to determine the optimal treatment approach for the individual patient.