Noncanonical hedgehog pathway activation through SRF-MKL1 promotes drug resistance in basal cell carcinomas.

Hedgehog pathway-dependent cancers can escape Smoothened (SMO) inhibition through mutations in genes encoding canonical hedgehog pathway components; however, around 50% of drug-resistant basal cell carcinomas (BCCs) lack additional variants of these genes. Here we use multidimensional genomics analysis of human and mouse drug-resistant BCCs to identify a noncanonical hedgehog activation pathway driven by the transcription factor serum response factor (SRF). Active SRF along with its coactivator megakaryoblastic leukemia 1 (MKL1) binds DNA near hedgehog target genes and forms a previously unknown protein complex with the hedgehog transcription factor glioma-associated oncogene family zinc finger-1 (GLI1), causing amplification of GLI1 transcriptional activity. We show that cytoskeletal activation through Rho and the formin family member Diaphanous (mDia) is required for SRF-MKL-driven GLI1 activation and for tumor cell viability. Remarkably, nuclear MKL1 staining served as a biomarker in tumors from mice and human subjects to predict tumor responsiveness to MKL inhibitors, highlighting the therapeutic potential of targeting this pathway. Thus, our study illuminates, for the first time, cytoskeletal-activation-driven transcription as a personalized therapeutic target for combatting drug-resistant malignancies

Postoperative Complications After Interpolated Flap Repair for Mohs Defects of the Nose: A Multicenter Prospective Cohort Study

BACKGROUND: Dermatologists perform most interpolated flaps after skin cancer resection. Prospective, multicenter data on complications after interpolated flap repair in this setting are limited. OBJECTIVE: To determine the rate of physician-reported complications after interpolated flap repair of the nose. METHODS: Multicenter, prospective cohort study of 169 patients undergoing 2-stage interpolated flap repair of post-Mohs nasal defects. Frequency of bleeding, infection, dehiscence, necrosis, hospitalization, and death in the 30 days after flap placement and flap takedown are reported. RESULTS: Patients experienced 23 complications after flap placement (13.61%) and 6 complications after flap takedown (3.55%) that were related to the surgical procedure. The most frequent complication after flap placement was bleeding (9, 5.33%, 95% confidence interval [CI]: 2.83%-9.82%). The most frequent complication after flap takedown was infection (5, 2.96%, 95% CI: 1.27%-6.74%). There was one hospitalization related to an adverse reaction to antibiotics. There were no deaths. CONCLUSION: Most complications after interpolated flap repair for post-Mohs defects of the nose are minor and are associated with flap placement. Interpolated flap repair for post-Mohs defects can be performed safely in the outpatient setting under local anesthesia

Combined inhibition of atypical PKC and histone deacetylase 1 is cooperative in basal cell carcinoma treatment

Advanced basal cell carcinomas (BCCs) circumvent Smoothened (SMO) inhibition by activating GLI transcription factors to sustain the high levels of Hedgehog (HH) signaling required for their survival. Unfortunately, there is a lack of efficacious therapies. We performed a gene expression-based drug repositioning screen in silico and identified the FDA-approved histone deacetylase (HDAC) inhibitor, vorinostat, as a top therapeutic candidate. We show that vorinostat only inhibits proliferation of BCC cells in vitro and BCC allografts in vivo at high dose, limiting its usefulness as a monotherapy. We leveraged this in silico approach to identify drug combinations that increase the therapeutic window of vorinostat and identified atypical PKC Ɩ/ʎ (aPKC) as a HDAC costimulator of HH signaling. We found that aPKC promotes GLI1-HDAC1 association in vitro, linking two positive feedback loops. Combination targeting of HDAC1 and aPKC robustly inhibited GLI1, lowering drug doses needed in vitro, in vivo, and ex vivo in patient-derived BCC explants. We identified a bioavailable and selective small-molecule aPKC inhibitor, bringing the pharmacological blockade of aPKC and HDAC1 into the realm of clinical possibility. Our findings provide a compelling rationale and candidate drugs for combined targeting of HDAC1 and aPKC in HH-dependent cancers

Patient-Reported Nasal Function and Appearance After Interpolation Flap Repair Following Skin Cancer Resection: A Multicenter Prospective Cohort Study

Among patients undergoing two-stage interpolated flap repair of nasal defects, nasal function, and appearance before surgery and at 16 weeks after flap takedown were compared using the Nasal Appearance and Function Evaluation Questionnaire (NAFEQ). Multicenter prospective cohort study. Adult patients with a nasal skin cancer anticipated to require two-stage interpolation flap repair completed the NAFEQ before surgery, at 1 week after flap placement, 4 weeks after flap takedown, and 16 weeks after flap takedown. One hundred sixty-nine patients were enrolled, with 138 patients completing both presurgical and 16-week post-takedown NAFEQs. Overall NAFEQ score increased by 1.09 points (1.91% improvement, confidence interval [95% CI -0.34 to 2.53]). NAFEQ functional subscale increased by 0.72 points (2.58% increase; 95% CI [0.10-1.35]) and appearance subscale increased by 0.37 points (1.28% improvement, 95% CI [-0.65 to 1.39]). At 16 weeks after flap takedown, patients\u27 perceptions of their nasal function and appearance are similar to or slightly improved when compared with their presurgical assessments