Nuclear lamin A/C phosphorylation by loss of androgen receptor leads to cancer-associated fibroblast activation.

Alterations in nuclear structure and function are hallmarks of cancer cells. Little is known about these changes in Cancer-Associated Fibroblasts (CAFs), crucial components of the tumor microenvironment. Loss of the androgen receptor (AR) in human dermal fibroblasts (HDFs), which triggers early steps of CAF activation, leads to nuclear membrane changes and micronuclei formation, independent of cellular senescence. Similar changes occur in established CAFs and are reversed by restoring AR activity. AR associates with nuclear lamin A/C, and its loss causes lamin A/C nucleoplasmic redistribution. AR serves as a bridge between lamin A/C and the protein phosphatase PPP1. Loss of AR decreases lamin-PPP1 association and increases lamin A/C phosphorylation at Ser 301, a characteristic of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the regulatory region of CAF effector genes of the myofibroblast subtype. Expression of a lamin A/C Ser301 phosphomimetic mutant alone can transform normal fibroblasts into tumor-promoting CAFs.

ANKRD1 is a mesenchymal-specific driver of cancer-associated fibroblast activation bridging androgen receptor loss to AP-1 activation.

There are significant commonalities among several pathologies involving fibroblasts, ranging from auto-immune diseases to fibrosis and cancer. Early steps in cancer development and progression are closely linked to fibroblast senescence and transformation into tumor-promoting cancer-associated fibroblasts (CAFs), suppressed by the androgen receptor (AR). Here, we identify ANKRD1 as a mesenchymal-specific transcriptional coregulator under direct AR negative control in human dermal fibroblasts (HDFs) and a key driver of CAF conversion, independent of cellular senescence. ANKRD1 expression in CAFs is associated with poor survival in HNSCC, lung, and cervical SCC patients, and controls a specific gene expression program of myofibroblast CAFs (my-CAFs). ANKRD1 binds to the regulatory region of my-CAF effector genes in concert with AP-1 transcription factors, and promotes c-JUN and FOS association. Targeting ANKRD1 disrupts AP-1 complex formation, reverses CAF activation, and blocks the pro-tumorigenic properties of CAFs in an orthotopic skin cancer model. ANKRD1 thus represents a target for fibroblast-directed therapy in cancer and potentially beyond.

Nuclear lamin A/C phosphorylation by loss of Androgen Receptor is a global determinant of cancer-associated fibroblast activation.

Alterations of nuclear structure and function, and associated impact on gene transcription, are a hallmark of cancer cells. Little is known of these alterations in Cancer-Associated Fibroblasts (CAFs), a key component of the tumor stroma. Here we show that loss of androgen receptor (AR), which triggers early steps of CAF activation in human dermal fibroblasts (HDFs), leads to nuclear membrane alterations and increased micronuclei formation, which are unlinked from induction of cellular senescence. Similar alterations occur in fully established CAFs, which are overcome by restored AR function. AR associates with nuclear lamin A/C and loss of AR results in a substantially increased lamin A/C nucleoplasmic redistribution. Mechanistically, AR functions as a bridge between lamin A/C with the protein phosphatase PPP1. In parallel with a decreased lamin-PPP1 association, AR loss results in a marked increase of lamin A/C phosphorylation at Ser 301, which is also a feature of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the transcription promoter regulatory region of several CAF effector genes, which are upregulated due to the loss of AR. More directly, expression of a lamin A/C Ser301 phosphomimetic mutant alone is sufficient to convert normal fibroblasts into tumor-promoting CAFs of the myofibroblast subtype, without an impact on senescence. These findings highlight the pivotal role of the AR-lamin A/C-PPP1 axis and lamin A/C phosphorylation at Ser 301 in driving CAF activation.

Sphingolipids control dermal fibroblast heterogeneity.

Human cells produce thousands of lipids that change during cell differentiation and can vary across individual cells of the same type. However, we are only starting to characterize the function of these cell-to-cell differences in lipid composition. Here, we measured the lipidomes and transcriptomes of individual human dermal fibroblasts by coupling high-resolution mass spectrometry imaging with single-cell transcriptomics. We found that the cell-to-cell variations of specific lipid metabolic pathways contribute to the establishment of cell states involved in the organization of skin architecture. Sphingolipid composition is shown to define fibroblast subpopulations, with sphingolipid metabolic rewiring driving cell-state transitions. Therefore, cell-to-cell lipid heterogeneity affects the determination of cell states, adding a new regulatory component to the self-organization of multicellular systems.

Sustained androgen receptor signaling is a determinant of melanoma cell growth potential and tumorigenesis.

Melanoma susceptibility differs significantly in male versus female populations. Low levels of androgen receptor (AR) in melanocytes of the two sexes are accompanied by heterogeneous expression at various stages of the disease. Irrespective of expression levels, genetic and pharmacological suppression of AR activity in melanoma cells blunts proliferation and induces senescence, while increased AR expression or activation exert opposite effects. AR down-modulation elicits a shared gene expression signature associated with better patient survival, related to interferon and cytokine signaling and DNA damage/repair. AR loss leads to dsDNA breakage, cytoplasmic leakage, and STING activation, with AR anchoring the DNA repair proteins Ku70/Ku80 to RNA Pol II and preventing RNA Pol II-associated DNA damage. AR down-modulation or pharmacological inhibition suppresses melanomagenesis, with increased intratumoral infiltration of macrophages and, in an immune-competent mouse model, cytotoxic T cells. AR provides an attractive target for improved management of melanoma independent of patient sex.

Intravitreal bevacizumab as primary treatment for retinal angiomatous proliferation: twelve-month results.

PURPOSE: To evaluate the short-term efficacy and safety of intravitreal bevacizumab for the treatment of retinal angiomatous proliferation. METHODS: Seventeen eyes from 16 patients with newly diagnosed retinal angiomatous proliferation underwent intravitreal injections of bevacizumab, 1.25 mg. The patients were scheduled for three monthly bevacizumab injections. Early Treatment of Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, central macular thickness on optical coherence tomography, and fluorescein angiographic findings were examined before and after treatment. Patients were followed-up for 12 months. RESULTS: The mean best-corrected visual acuity (+/- standard deviation [SD]) at baseline was 39.53 (+/-10.40) letters (Snellen equivalent: 20/42). At 12 months after treatment the mean best-corrected visual acuity (+/-SD) improved significantly (P = 0.0000001) to 47.88 (+/-11.78) letters (Snellen equivalent: 20/28). Best-corrected visual acuity improved 3 ETDRS lines or more in 3 (17.65%) of 17 treated eyes, 14 (82.35%) eyes were stable, and 15 (88.23%) eyes gained 1 or more ETDRS lines. The mean central macular thickness (+/-SD) at baseline was 297 (+/-60.72) microm. At 12 months after treatment, the mean central macular thickness (+/-SD) reduced significantly (P = 0.00001) to 237 (+/-28.80) microm. At the 12-month follow-up, absence of fluorescein leakage was demonstrated in 14 (82%) of 17 treated eyes. No ocular or systemic adverse effects from treatment were encountered. CONCLUSION: The 12-month results of intravitreal bevacizumab for retinal angiomatous proliferation are very promising with no apparent short-term safety concerns. Treated eyes had a significant functional and anatomical improvement. Further studies will be needed to better determine long-term efficacy and safety.

A Combination of Approved Antibodies Overcomes Resistance of Lung Cancer to Osimertinib by Blocking Bypass Pathways.

Purpose: Because of emergence of resistance to osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), no targeted treatments are available for patients with lung cancer who lose sensitivity due to new mutations or bypass mechanisms. We examined in animals and in vitro an alternative therapeutic approach making use of antibodies.Experimental Design: An osimertinib-sensitive animal model of lung cancer, which rapidly develops drug resistance, has been employed. To overcome compensatory hyperactivation of ERK, which we previously reported, an anti-EGFR antibody (cetuximab) was combined with other antibodies, as well as with a subtherapeutic dose of osimertinib, and cancer cell apoptosis was assayed.Results: Our animal studies identified a combination of three clinically approved drugs, cetuximab, trastuzumab (an anti-HER2 mAb), and osimertinib (low dose), as an effective and long-lasting treatment that is able to prevent onset of resistance to osimertinib. A continuous schedule of concurrent treatment was sufficient for effective tumor inhibition and for prevention of relapses. Studies employing cultured cells and analyses of tumor extracts indicated that the combination of two mAbs and a subtherapeutic TKI dose sorted EGFR and HER2 for degradation; cooperatively enhanced apoptosis; inhibited activation of ERK; and reduced abundance of several bypass proteins, namely MET, AXL, and HER3.Conclusions: Our in vitro assays and animal studies identified an effective combination of clinically approved drugs that might overcome resistance to irreversible TKIs in clinical settings. The results we present attribute the long-lasting effect of the drug combination to simultaneous blockade of several well-characterized mechanisms of drug resistance. Clin Cancer Res; 24(22); 5610-21. ©2018 AACR See related commentary by Fan and Yu, p. 5499.

Androgen receptor functions as transcriptional repressor of cancer-associated fibroblast activation.

The aging-associated increase of cancer risk is linked with stromal fibroblast senescence and concomitant cancer-associated fibroblast (CAF) activation. Surprisingly little is known about the role of androgen receptor (AR) signaling in this context. We have found downmodulated AR expression in dermal fibroblasts underlying premalignant skin cancer lesions (actinic keratoses and dysplastic nevi) as well as in CAFs from the 3 major skin cancer types, squamous cell carcinomas (SCCs), basal cell carcinomas, and melanomas. Functionally, decreased AR expression in primary human dermal fibroblasts (HDFs) from multiple individuals induced early steps of CAF activation, and in an orthotopic skin cancer model, AR loss in HDFs enhanced tumorigenicity of SCC and melanoma cells. Forming a complex, AR converged with CSL/RBP-Jκ in transcriptional repression of key CAF effector genes. AR and CSL were positive determinants of each other's expression, with BET inhibitors, which counteract the effects of decreased CSL, restoring AR expression and activity in CAFs. Increased AR expression in these cells overcame the consequences of CSL loss and was by itself sufficient to block the growth and tumor-enhancing effects of CAFs on neighboring cancer cells. As such, the findings establish AR as a target for stroma-focused cancer chemoprevention and treatment.

An oligoclonal antibody durably overcomes resistance of lung cancer to third-generation EGFR inhibitors.

Epidermal growth factor receptor (EGFR) mutations identify patients with lung cancer who derive benefit from kinase inhibitors. However, most patients eventually develop resistance, primarily due to the T790M second-site mutation. Irreversible inhibitors (e.g., osimertinib/AZD9291) inhibit T790M-EGFR, but several mechanisms, including a third-site mutation, C797S, confer renewed resistance. We previously reported that a triple mixture of monoclonal antibodies, 3×mAbs, simultaneously targeting EGFR, HER2, and HER3, inhibits T790M-expressing tumors. We now report that 3×mAbs, including a triplet containing cetuximab and trastuzumab, inhibits C797S-expressing tumors. Unlike osimertinib, which induces apoptosis, 3×mAbs promotes degradation of the three receptors and induces cellular senescence. Consistent with distinct mechanisms, treatments combining 3×mAbs plus sub-inhibitory doses of osimertinib synergistically and persistently eliminated tumors. Thus, oligoclonal antibodies, either alone or in combination with kinase inhibitors, might preempt repeated cycles of treatment and rapid emergence of resistance.

Choroidal neovascularization in pathologic myopia: intravitreal ranibizumab versus bevacizumab--a randomized controlled trial.

PURPOSE: To compare the short-term efficacy and safety of intravitreal ranibizumab versus bevacizumab in treating myopic choroidal neovascularization (CNV). DESIGN: Prospective, comparative, randomized, interventional study. METHODS: Thirty-two eyes from 32 patients with myopic CNV were consecutively enrolled and randomly treated, in a 1:1 ratio, with intravitreal ranibizumab (0.5 mg) or bevacizumab (1.25 mg) as needed, after the first injection. ETDRS best-corrected visual acuity (BCVA), foveal center thickness (FCT) on optical coherence tomography (OCT), and fluorescein angiographic findings were examined before and after treatment. Patients were followed up for 6 months. RESULTS: No statistically significant difference in the BCVA improvement, as well as in the FCT reduction, was found between groups during follow-up (P value at 1, 3, 6 months > .05). Complete resolution of fluorescein leakage was observed in all 16 bevacizumab-treated eyes and in 15 out of 16 (93.7%) ranibizumab-treated eyes. No ocular or systemic adverse effects from treatment were encountered. CONCLUSION: This randomized clinical study cannot determine a statistically significant difference in anti-VEGF treatment effect between ranibizumab and bevacizumab for the treatment of CNV secondary to pathologic myopia. A larger study is required to determine the relative efficacy and duration of action of these drugs.

Intravitreal bevacizumab treatment for choroidal neovascularization in pathologic myopia: 12-month results.

PURPOSE: To evaluate the short-term efficacy and safety of intravitreal bevacizumab for the treatment of myopic choroidal neovascularization (CNV). DESIGN: Prospective, nonrandomized, interventional case series. METHODS: Twenty eyes from 20 patients with CNV secondary to pathologic myopia participated in this prospective nonrandomized interventional case series. All patients were scheduled for three monthly intravitreal bevacizumab 1.25 mg injections. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity (BCVA), foveal center thickness (FCT) on optical coherence tomography (OCT), and fluorescein angiographic findings were examined before and after treatment. Patients were followed up for 12 months. RESULTS: The mean BCVA (+/- standard deviation [SD]) at baseline was 24.8 (+/- 11.86) letters (Snellen equivalent: 20/80). At 12 months after treatment, the mean BCVA (+/- SD) improved significantly (P = .000001) to 43 (+/- 12.38) letters (Snellen equivalent: 20/35). At 12 month follow-up, BCVA improved 10 letters or more in 18 (90%) out of 20 treated eyes and improved 15 letters or more in 14 (70%) out of 20 treated eyes. No treated eyes experienced a worsening of BCVA from baseline. The mean FCT (+/- SD) at baseline was 223 (+/- 47.43) microns. At 12 months after treatment, the mean FCT (+/- SD) reduced to 206 (+/- 50.87) microns. This reduction in FCT after treatment was not statistically significant (P = .11). At 12 months follow-up, absence of fluorescein leakage from the CNV was demonstrated in 19 (95%) out of 20 treated eyes and persistent leakage in one eye (5%). None of the 19 eyes that had CNV closure experienced recurrence at 12-month follow-up. No ocular or systemic adverse effects from treatment were encountered. CONCLUSION: These results of intravitreal bevacizumab in myopic CNV are very promising with no apparent short-term safety concerns. At 12 months, treated eyes had a significant improvement in visual acuity (VA). OCT findings, as well, showed a trend consistent with the beneficial changes observed for VA. Treatment resulted in complete absence of angiographic leakage in 95% of eyes. Further studies will be needed to better determine long-term efficacy and safety.

Photorefractive keratectomy in the management of refractive accommodative esotropia in young adult patients.

PURPOSE: To evaluate the visual, motor, and sensory outcomes of photorefractive keratectomy (PRK) in the treatment of purely refractive accommodative esotropia in young adult patients. SETTING: Policlinico Umberto I, Department of Ophthalmology, Rome, Italy. METHODS: This prospective study comprised patients with hyperopia and purely accommodative hyperopic esotropia. A complete ophthalmologic examination was performed preoperatively and 1, 3, and 12 months postoperatively. The examination included uncorrected (UDVA) and corrected (CDVA) distance visual acuities and orthoptic and sensory tests. All patients also had keratometry, pachymetry, and corneal topography assessment before and after treatment. Treatment was performed using a Technolas 217 excimer laser. RESULTS: Thirty eyes of 15 patients (mean age 30.8 years) were treated. Preoperatively, the CDVA was 20/30 or better in all eyes and the mean cycloplegic spherical equivalent (SE) was +3.50 diopters (D). One year postoperatively, the UDVA was 20/30 or better in all eyes and the mean SE was -0.01 D. The mean esotropic deviation for distance vision without correction preoperatively was 8.7 prism diopters. At 1 year of follow-up, 12 patients achieved orthophoria and 3 patients had a reduction in the angle of deviation. There were no intraoperative or postoperative complications. Stereopsis was unaffected by treatment in all patients. CONCLUSIONS: Photorefractive keratectomy was effective in the treatment of purely accommodative esotropia in young adult patients at a follow-up of 1 year. There were no cases of visual acuity loss or complications from the laser treatment.