A comprehensive review of the role of the hedgehog pathway and vismodegib in the management of basal cell carcinoma

Development of a molecularly imprinted polymer-based electrochemical sensor with metal-organic frameworks for monitoring the antineoplastic drug vismodegib

A novel and robust electrochemical sensing tool for the determination of vismodegib (VIS), an anticancer drug, has been developed by integrating the selective recognition capabilities of molecularly imprinted polymer (MIP) and the sensitivity enhancement capability of metal-organic framework (MOF). Prior to this step, the electrochemical behavior of VIS was investigated using a bare glassy carbon electrode (GCE). It was observed that in 0.5 M H2SO4 solution as electrolyte, VIS has an oxidation peak around 1.3 V and the oxidation mechanism is diffusion controlled. The determination of VIS in a standard solution using a bare GCE showed a linear response in the concentration range from 2.5 μM to 100 μM, with a limit of detection (LOD) of 0.75 μM. Since sufficient sensitivity and selectivity could not be achieved with bare GCE, a MIP sensor was developed in the next step of the study. For this purpose, the GCE surface was first modified by drop casting with as-synthesized Co-MOF. Subsequently, a MIP network was synthesized via a thermal polymerization approach using 2-acrylamido-2-methylpropanesulfonic acid (AMPS) as monomer and VIS as template. MOFs are ideal electrode materials due to their controllable and diverse morphologies and modifiable surface properties. These characteristics enable the development of MIPs with more homogeneous binding sites and high affinity for target molecules. Integrating MOFs could help the performance of sensors with the desired stability and reproducibility. Electrochemical analysis revealed an observable enhancement of the output signal by the incorporation of MOF molecules, which is consistent with the sensitivity-enhancing role of MOF by providing more anchoring sites for the attachment of the polymer texture to the electrode surface. This MOF-MIP sensor exhibited impressive linear dynamic ranges ranging from 0.1 to 1.0 pM for VIS, with detection limits in the low picomolar range. In addition, the MOF-MIP sensor offers high accuracy, selectivity and precision for the determination of VIS, with no interference observed from complex media of serum samples. Additionally, in this study, Analytical GREEnness metric (AGREE), Analytical GREEnness preparation (AGREEprep) and Blue Applicability Grade Index (BAGI) were used to calculate the green profile score.

Metastatic basal cell carcinoma to the bone: A case of bone metastasis in uncommon sites

Basal cell carcinoma (BCC) is the most common malignant tumor of the skin. Despite the indolent nature, metastatic BCC can occur, albeit rarely. Metastasis to the bone is very rare. From its approval, mBCC patients are treated with vismodegib, a selective hedgehog pathway inhibitor. Unfortunately, in recent period, it was demonstrated an emergence of drug resistance, due to Smoothened (SMO) mutation. To date, several groups are studying the effectiveness of immunotherapy in BCC. Clinical trials with Immune Checkpoint Inhibitors are ongoing. We report the rare case of a man with multiple bony metastasis, with a resistance to vismodegib, and we evaluated all manuscripts in literature reporting bone metastasis. Moreover, we review all the manuscripts in literature reporting bone metastasis, and we summarize the main therapeutic strategies, and the further perspectives.

Periocular basal cell carcinoma - clinical perspectives

Basal cell carcinoma (BCC) as a non-melanoma skin cancer type is the most common malignant tumor throughout the world. The incidence is higher in age over 60. The intense of exposure to ultraviolet radiation is one of the known risk factors. Over 50% of BCC of the periocular region initially occur on the lower lid and inner angle. Literature review of treatment options for basal cell carcinoma, which consist of surgery, or combined techniques plus vismodegib, radiotherapy and imiquimod. The first consideration for treatment of periocular BCC is radical surgical excision using Mohs micrographic technique. Functional and esthetic outcome in patients are important after clear excisions and reconstruction should be carefully considered. Radical exenteration is considered in the case of orbital invasion of high-risk aggressive BCC.

Vismodegibfor the treatment of radiation-induced basal cell carcinoma - a case report and brief literature study

Vismodegib is playing an increasing role in the treatment of locally advanced or metastatic basal cell carcinoma (BCC) that is not a candidate for surgery or radiotherapy, and also in radiation-induced BCC. A 22-year-old man with a history of Hodgkin lymphoma, nodular sclerosis stage IIA, from October 1994 to February 1995 treated with 25 mg/m² doxorubicin, 10 IU/m² bleomycin, 6 mg/m² vinblastine, and 375 mg/m² dacarbazine for four cycles, followed byconformal beam radiotherapy (EBRT) on laterocervical, supraclavear, and mediastinal nodes up to a total dose of 30 Gy and following EBRT boost on mediastinal nodes up to a dose of 10 Gy. Subsequently, the patient underwent conformal EBRT on lomboaortic nodes up to total dose of 30 Gy at the University Hospital of Pisa until May 1995. There was no evidence of disease, until March 2012 when the patient developed severalBCCs, occurring in the field of prior radiation, treated with local excisions. No mutations of Hedgehog (Hh) pathway or other genes were found and nevoid basal cell carcinoma syndrome was not diagnosed. In February 2018, the patient began therapy with vismodegib at standard dose of 150 mgorally daily and was treated for 10 months, with low adverse events and with pathological complete response of disease until July 2019. This experience shows that there are, however very few, BCCs not associated with genetic disorders. Vismodegib seems to be an effective and safe therapeutic approach also for radiation-related BCCs, associated with relatively low toxicity.

Gene-Related Response of Basal Cell Carcinoma to Biologic Treatment with Vismodegib

We aimed to characterise the response of locally advanced basal cell carcinoma (BCC) to systemic treatment with Vismodegib, a Hedgehog pathway inhibitor, by changes in the expression levels of Hedgehog pathway genes. Data were collected prospectively on 12 patients treated systemically for locally advanced BCC. Biopsy samples taken on admission and after treatment cessation were analysed pathologically and with the NanoString nCounter system to quantify the expression of 40 Hedgehog signaling pathway genes. Findings were compared before and after treatment, between complete and partial responders, and with localised BCC samples from 22 patients. Sixteen Hedgehog pathway genes changed significantly from before to after treatment. GAS1 was the only gene with a significantly different expression at baseline between complete responders (6 patients) and partial responders (4 patients) to Vismodegib (P = 0.014). GAS, GLIS2 and PRKACG1 showed different expression before treatment between the locally advanced and localised BCCs. The baseline expression level of GAS1 appears to be predictive of the response of locally advanced BCC to systemic Vismodegib treatment. A change in expression of many Hedgehog pathway genes, albeit expected by the known activity of Vismodegib, may nevertheless serve as an indicator of the response potential of the tumour.

Smoothened receptor inhibitor vismodegib for the treatment of basal cell carcinoma: a retrospective analysis of efficacy and side effects

Background: Smoothened receptor inhibitor vismodegib is indicated to treat locally advanced basal cell carcinoma (laBCC) and lesions in nevoid basal cell carcinoma syndrome (NBCCS).Methods: We treated 11 patients - including four NBCCS and seven laBCC patients - with vismodegib at our department.Results: Complete remission was achieved in three cases, without relapse after discontinuation. Two of the aforementioned patients had NBCCS, in their cases further treatment might be needed. Two patients showed improvement, but later passed away due to unrelated conditions. Two patients with laBCC initially showed remission, then the treatment was suspended due to side effects. After re-administration of the drug, loss of efficacy was observed. We did not observe therapy resistance in our NBCCS group. The rest of the patients showed good response to therapy, but have not reached full remission yet. The main side effects of vismodegib were muscle cramps, dysgeusia, nausea and alopecia. The frequency of adverse events did not show significant differences between the patient groups.Conclusions: Our results show that vismodegib therapy is effective in the treatment of BCC; however, side effects are often severe. Since the suspension of treatment can lead to therapy resistance, the management of side effects is of great importance.

Overcoming the emerging drug resistance of smoothened: an overview of small-molecule SMO antagonists with antiresistance activity

Hedgehog (HH) signaling pathway plays vital roles in controlling embryonic cell fate and homeostatic, and becomes dormant in mature individuals, aberrant activation of HH signaling pathway is involved in a number of human cancers. Smoothened (SMO), a vital transducer of HH signaling pathway, attracts significant attentions in HH signaling pathway-related cancer therapy. The approval of SMO antagonists vismodegib proves that SMO is a promising therapeutic target, and a number of SMO antagonists are reported since then. However, high incidence of tumor recurrence with the clinical application of vismodegib urges exploring of novel drugs with antiresistance profiles. This review provides an overview of SMO mutations reported in the literature, crystal structures of SMO, as well as reported antagonists with antiresistance profiles.

Conventional Versus Giant Basal Cell Carcinoma, a Review of 57 Cases: Histologic Differences Contributing to Excessive Growth

Background:

Giant basal cell carcinoma (GBCC) is defined as a basal cell carcinoma (BCC) exceeding 5 cm in size. While these tumors impart significant morbidity due to local tissue destruction and have a higher rate of metastatic disease than their conventional (smaller) counterparts, reasons for their large size remain unclear. While theories relating to neglect or faster growth rate are often invoked; to date, there has not been a comprehensive evaluation of the histologic features of these large tumors that may contribute to their size.

Methods:

Histologic features of GBCCs (n = 29) were evaluated and compared to those of conventional BCC (n = 28). Available clinical demographic data were also reviewed.

Results:

GBCCs, in addition to overall larger size, more often were thicker, displayed ulceration, and showed a more infiltrative growth pattern than their conventional counterparts. These rare tumors also displayed an insignificant increased propensity for a brisk host immune response, and the infiltrate significantly more often included clusters of plasma cells.

Conclusions:

Most histologic features seen in GBCCs likely reflect their large size. Histologic features alone are unlikely to explain the size of these rare tumors. The possibility of an altered host immune response contributing to the growth of these tumors requires further investigation.

Disruption of Hedgehog Signaling by Vismodegib Leads to Cleft Palate and Delayed Osteogenesis in Experimental Design

The function of hedgehog signaling has previously been shown to be crucial for craniofacial development. In this study, we treated C57/BL6J mice with the hedgehog pathway inhibitor vismodegib by oral gavage to establish a stable vismodegib-induced cleft palate model. At E10.5 and E12.5, mice in the experimental group were treated with 100 mg/kg of vismodegib, whereas mice in the control group were treated with solvent. The treated pregnant mice were sacrificed on E13.5, E14.5, E15.5, and E16.5. Palatal shelf growth was evaluated via histological and immunohistochemical analyses as well as palatal organ culture. Immunohistochemical staining was performed to examine the expression of osteogenic proteins in the palatal tissue. A high proportion of the mice administered 2 doses of 100 mg/kg of vismodegib displayed a cleft palate. Histologic examination revealed severely retarded palatal shelf growth and thickened epithelium in the experimental group. Vismodegib exposure induced complete cleft palate, which was attributed to a reduced cell proliferation rate in the palatal mesenchyme along the anterior-posterior axis. Moreover, this model also showed delayed ossification in the region of palatine bone with downregulation of Indian hedgehog (Ihh) protein. Our results suggest that vismodegib can be used to inhibit hedgehog signaling to affect palatal morphogenesis. Under treatment with this exogenous inhibitor, the cell proliferation rate of the palatal shelves and the osteogenic potential of the hard palate were decreased, which likely contributed to the complete cleft palate.

Ocular basal cell carcinoma: a brief literature review of clinical diagnosis and treatment

Basal cell carcinoma (BCC) is a common malignant tumor throughout the world. One of the known risk factors of BCC is intense exposure to ultraviolet radiation. More than 50% of BCCs of the eyelid initially occur on the lower lid. The gold standard of diagnosis of BCC is histopathology. Treatment options for BCC consist of surgery, vismodegib, radiotherapy and imiquimod. Surgical excision using Mohs micrographic surgery or wide surgical excision with frozen section margin control is the first consideration for treatment of periocular BCC. Eyelid reconstruction should be carefully considered as both function and esthetic outcome in patients are important after clear excision of tumors. Exenteration is considered in the case of extensive orbital invasion or high-risk aggressive tumors in order to reduce the rate of recurrence.

Role of Vismodegib in the Management of Advanced Periocular Basal Cell Carcinoma

BACKGROUND

Vismodegib is the first selective hedgehog pathway inhibitor approved to treat locally advanced and metastatic basal cell carcinoma (BCC). Limited information is available concerning its role in managing advanced BCC around the eye.

METHODS

The medical literature was searched for cases of nonsyndromic periocular BCC treated with vismodegib. Clinical information was abstracted and analyzed. In addition, a review of the pharmacology of vismodegib, including general effectiveness and safety, was conducted.

RESULTS

Thirty study patients with nonsyndromic periocular BCC treated with vismodegib were found in the literature. Vismodegib was used in 3 ways: medical therapy, adjuvant therapy prior to surgery or radiotherapy, and treatment of positive surgical margins. Complete regression was reported in 9 study patients (30%), with follow-up visits after therapy averaging fewer than 5 months. Four study participants developed squamous cell carcinoma while receiving treatment.

CONCLUSIONS

Too few cases exist to draw any conclusions on the role that vismodegib might play in the management of periocular BCC. In addition, long-term follow-up data are not yet available. Although the objective response rate of advanced BCC is impressive in study patients receiving vismodegib, well-controlled clinical studies are needed to determine whether vismodegib has any impact on survival or quality of life.

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.

Next-generation sequencing of the basal cell carcinoma miRNome and a description of novel microRNA candidates under neoadjuvant vismodegib therapy: an integrative molecular and surgical case study

BACKGROUND

MicroRNAs (miRNAs) have been identified as key players in posttranscriptional gene regulation and have a significant impact on basal cell carcinoma (BCC) development. The Sonic hedgehog pathway inhibitor vismodegib has been approved for oral therapy of metastatic or advanced BCC. Here, a high-throughput miRNA sequencing analysis was carried out to identify differentially expressed miRNAs and possible novel miRNA candidates in vismodegib-treated BCC tissue. Additionally, we described our surgical experience with neoadjuvant oral vismodegib therapy.

PATIENTS AND METHODS

A punch biopsy (4 mm) from a patient with an extensive cranial BCC under oral vismodegib therapy and a corresponding nonlesional epithelial skin biopsy were harvested. Total RNA was isolated, after which a sequencing cDNA library was prepared, and cluster generation was carried out, which was followed by an ultra-high-throughput miRNA sequencing analysis to indicate the read number of miRNA expression based on miRBase 21. In addition to the identification of differentially expressed miRNAs from RNA sequencing data, additional novel miRNA candidates were determined with a tool for identifying new miRNA sequences (miRDeep2).

RESULTS

We identified 33 up-regulated miRNAs (fold change ≥2) and 39 potentially new miRNA candidates (miRDeep scores 0-43.6). A manual sequence analysis of the miRNA candidates on the genomic locus of chromosome 1 with provisional IDs of chr1_1913 and chr1_421 was further carried out and rated as promising (chr1_1913) and borderline (chr1_421). Histopathology revealed skip lesions in clinically healthy appearing skin at the tumor margins, which were the cause of seven re-excisions by micrographic controlled surgery to achieve tumor-free margins.

CONCLUSION

miRNA sequencing revealed novel miRNA candidates that need to be further confirmed in functional Dicer knockout studies. Clinically, on the basis of our surgical experience described here, neoadjuvant vismodegib therapy in BCC appears to impede histopathologic evaluations with effects on surgical therapy. Thus, larger studies are necessary, but are not preferable at this time if other options are available.