Topical Delivery of Hedgehog Inhibitors: Current Status and Perspectives

Novel C-2 Aromatic Heterocycle-Substituted Triterpenoids Inhibit Hedgehog Signaling in GLI1 Overexpression Cancer Cells

The hedgehog signaling pathway plays an important role in vertebrate embryonic development, tissue homeostasis, and tumorigenesis. Constitutive activation of Hh signaling in various human tumors leads to GLI-mediated transcription and tumor progression. Based on the preliminary screening of a large library of known triterpenes that exhibited interesting Hh inhibitory activity, we designed and synthesized a new series of triterpenoid analogues containing aromatic heterocyclic substituents at position C-2 to enhance their interference with Hh signaling. In this study, we evaluated the effect of 15 synthesized triterpenoids on cell proliferation and Hh pathway activity in relevant cancer cell lines. Among these compounds, two derivatives, 11a and 11b, both featuring a furan ring at position C-2, demonstrated potent inhibitory effects on proliferation and induced cell death in nonsmall cell lung cancer (NSCLC) and prostate cancer cell lines exhibiting hyper-activated Hh signaling. Moreover, these compounds significantly reduced GLI-mediated transcription in cell-based reporter assays. Detailed immunoblot analyses revealed that compounds 11a and 11b decreased the expression of endogenous GLI1 protein and its target genes associated with tumor progression and proliferation, such as Cyclin D1, N-Myc, and Bcl-2, in A549 and DU-145 cancer cells. These findings suggest that the antiproliferative effects of 11a and 11b are mediated through inhibition of the Hh signaling pathway and are promising candidates for the development of new anticancer therapies targeting Hh-dependent tumors.

The History and Advancement of Light, Lasers, and Energy-Based Devices in Dermatologic Surgery

BACKGROUND

From the theoretical foundations of laser and energy-based applications for the skin to the development of advanced medical devices, the field of dermatologic surgery has undergone transformative changes.

OBJECTIVE

To review the scientific and clinical advancement of laser and energy-based therapies within dermatologic surgery.

MATERIALS AND METHODS

A literature search was conducted to identify important scientific advancements and landmark studies on light, laser, and energy-based devices within the field of dermatologic surgery.

RESULTS

Since the introduction of selective photothermolysis principles in the 1980s, numerous laser and energy-based devices have been developed to effectively treat vascular lesions, target pigmentation, remove tattoos, rejuvenate the skin, and remove hair. Beyond aesthetic applications, photodynamic therapy was introduced to treat various neoplastic and inflammatory conditions. Lasers have also been employed to enhance transcutaneous drug delivery, and new lasers continue to emerge for treating common inflammatory conditions, such as acne. These innovations have contributed to a paradigm shift toward safe and effective, but less invasive, procedure-based treatment in addressing medical and aesthetic concerns in dermatology.

CONCLUSION

Dermatologists have consistently led the way in the continuous development and innovative application of laser and energy-based devices to effectively address a variety of skin conditions.

Comprehensive review of drug resistance in mammalian cancer stem cells: implications for cancer therapy

Cancer remains a significant global challenge, and despite the numerous strategies developed to advance cancer therapy, an effective cure for metastatic cancer remains elusive. A major hurdle in treatment success is the ability of cancer cells, particularly cancer stem cells (CSCs), to resist therapy. These CSCs possess unique abilities, including self-renewal, differentiation, and repair, which drive tumor progression and chemotherapy resistance. The resilience of CSCs is linked to certain signaling pathways. Tumors with pathway-dependent CSCs often develop genetic resistance, whereas those with pathway-independent CSCs undergo epigenetic changes that affect gene regulation. CSCs can evade cytotoxic drugs, radiation, and apoptosis by increasing drug efflux transporter activity and activating survival mechanisms. Future research should prioritize the identification of new biomarkers and signaling molecules to better understand drug resistance. The use of cutting-edge approaches, such as bioinformatics, genomics, proteomics, and nanotechnology, offers potential solutions to this challenge. Key strategies include developing targeted therapies, employing nanocarriers for precise drug delivery, and focusing on CSC-targeted pathways such as the Wnt, Notch, and Hedgehog pathways. Additionally, investigating multitarget inhibitors, immunotherapy, and nanodrug delivery systems is critical for overcoming drug resistance in cancer cells.

Transcriptomic Analysis of Early-Stage Basal Cell Carcinomas in Murine Skin Following Topical Treatments With Ablative Fractional Laser and Vismodegib

Recent studies have demonstrated that ablative fractional laser (AFL) can inhibit the hedgehog pathway, enhance immune infiltration and clear basal cell carcinomas (BCCs) in murine models. In this study, we applied RNA sequencing to further characterise the impact of AFL on the transcriptome of murine skin containing early-stage microscopic BCCs, contrasting it with the effects of topical application of the hedgehog inhibitor vismodegib. Our results showed that BCC induction in murine skin was primarily linked to gene upregulation (significantly upregulated genes: 277, significantly downregulated genes: 24). Characterisation of these genes with Ingenuity Pathway Analysis showed that tumour induction was associated with activation of BCC and Sonic Hedgehog signalling. Both AFL and vismodegib treatments reversed these changes, with vismodegib demonstrating superior performance by reversing most of the upregulated genes (AFL: 59/277; vismodegib: 180/277). Surprisingly, Ingenuity Pathway Analysis also revealed that both AFL and vismodegib treatments caused considerable immune cell infiltration. Based on gene set enrichment analysis and cell type deconvolution, AFL treatment resulted in the largest immune cell recruitment, which for both treatments primarily consisted of infiltrating neutrophils, macrophages and monocytes. In conclusion, the distinct effects observed in BCC skin following AFL and vismodegib treatment suggest key differences between the two interventions. Future applications of AFL or vismodegib treatments could leverage their individual effects, for example by combining the effect of AFL on the immune system with other topical treatments.

Health-related quality of life in patients with metastatic basal cell carcinoma treated with cemiplimab: Analysis of a phase 2 trial

BACKGROUND

A phase 2 cemiplimab study (NCT03132636) demonstrated a 24.1% objective response rate in patients diagnosed with metastatic basal cell carcinoma (mBCC) who were not candidates for continued hedgehog inhibitor (HHI) therapy due to intolerance to previous HHI therapy, disease progression while receiving HHI therapy, or having not better than stable disease on HHI therapy after 9 months. Here, health-related quality of life (QoL) for this patient population is reported.

METHODS

Adult patients with mBCC were treated with intravenous cemiplimab at a dose of 350 mg every 3 weeks for 5 treatment cycles of 9 weeks/cycle then 4 treatment cycles of 12 weeks/cycle. Patients completed the European Organisation for Research and Treatment of Cancer Quality of Life-Core 30 (QLQ-C30) and Skindex-16 questionnaires at baseline and Day 1 of each cycle. Across Cycles 2 to 9, the overall change from baseline was analyzed using a mixed model with repeated measures. Responder analyses determined clinically meaningful improvement or deterioration (changes ≥10 points) or maintenance across all scales.

RESULTS

Patients reported low symptom burden and moderate-to-high functioning at baseline. Maintenance for QLQ-C30 global health status (GHS)/QoL and across all functioning and symptom scales was indicated by overall mean changes from baseline. Clinically meaningful improvement or maintenance was reported at Cycle 2 for GHS/QoL (77%), functioning scales (77% to 86%), and symptom scales (70% to 93%), with similar proportions of improvement or maintenance at Cycles 6 and 9, excluding fatigue. On the Skindex-16, clinically meaningful improvement or maintenance was reported across the emotional, symptom, and functional subscales, in 76%-88% of patients at Cycle 2, which were generally maintained at Cycles 6 and 9. Overall mean changes from baseline showed maintenance across these subscales.

CONCLUSIONS

The majority of patients treated with cemiplimab reported improvement or maintenance in GHS/QoL and functioning while maintaining a low symptom burden.

Topical and Intralesional Immunotherapy for the Management of Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is the most common type of cancer among the white population. Individuals with fair skin have an average lifetime risk of around 30% for developing BCC, and there is a noticeable upward trend in its incidence rate. The principal treatment objectives for BCC involve achieving the total excision of the tumor while maximizing the preservation of function and cosmesis. Surgery is considered the treatment of choice for BCC for two main reasons: it allows for the highest cure rates and facilitates histological control of resection margins. However, in the subgroup of patients with low-risk recurrence or medical contraindications for surgery, new non-surgical treatment alternatives can provide an excellent oncological and cosmetic outcome. An evident and justified instance of these local therapies occurred during the COVID-19 pandemic, a period when surgical interventions carried out in hospital settings were not a viable option.

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.

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.

Itraconazole-Loaded Ufasomes: Evaluation, Characterization, and Anti-Fungal Activity against Candida albicans

Numerous obstacles challenge the treatment of fungal infections, including the uprising resistance and the low penetration of available drugs. One of the main active agents against fungal infections is itraconazole (ITZ), with activity against a broad spectrum of fungi while having few side effects. The aim of this study was to design ufasomes, oleic acid-based colloidal carriers, that could encapsulate ITZ to improve its penetration power. Employing a 2²3¹ factorial design, the effect of three independent factors (oleic acid amount, cholesterol concentration, and ITZ amount) was investigated and evaluated for the percentage encapsulation efficiency (%EE), particle size (PS), and zeta potential (ZP). Optimization was performed using Design^® expert software and the optimized ITZ-loaded ufasomes obtained had %EE of 99.4 ± 0.7%, PS of 190 ± 1 nm, and ZP of -81.6 ± 0.4 mV, with spherical unilamellar morphology and no aggregation. An in vitro microbiological study was conducted to identify the minimum inhibitory concentration of the selected formula against Candida albicans, which was found to be 0.0625 μg/mL. Moreover, the optimized formula reduced the expression of toll-like receptors-4 and pro-inflammatory cytokine IL-1β secretion in the C. albicans-infected fibroblasts, indicating that the proposed ITZ-loaded ufasomes are a promising drug delivery system for ITZ.