Rainer Kunstfeld

VEGF-A induces tumor and sentinel lymph node lymphangiogenesis and promotes lymphatic metastasis

The mechanisms of tumor metastasis to the sentinel lymph nodes are poorly understood. Vascular endothelial growth factor (VEGF)-A plays a principle role in tumor progression and angiogenesis; however, its role in tumor-associated lymphangiogenesis and lymphatic metastasis has remained unclear. We created transgenic mice that overexpress VEGF-A and green fluorescent protein specifically in the skin, and subjected them to a standard chemically-induced skin carcinogenesis regimen. We found that VEGF-A not only strongly promotes multistep skin carcinogenesis, but also induces active proliferation of VEGF receptor-2–expressing tumor-associated lymphatic vessels as well as tumor metastasis to the sentinel and distant lymph nodes. The lymphangiogenic activity of VEGF-A–expressing tumor cells was maintained within metastasis-containing lymph nodes. The most surprising finding of our study was that even before metastasizing, VEGF-A–overexpressing primary tumors induced sentinel lymph node lymphangiogenesis. This suggests that primary tumors might begin preparing their future metastatic site by producing lymphangiogenic factors that mediate their efficient transport to sentinel lymph nodes. This newly identified mechanism of inducing lymph node lymphangiogenesis likely contributes to tumor metastasis, and therefore, represents a new therapeutic target for advanced cancer and/or for the prevention of metastasis.

VEGF-A promotes tissue repair-associated lymphatic vessel formation via VEGFR-2 and the α1β1 and α2β1 integrins

Vascular endothelial growth factor‐A (VEGF‐A) is strongly up‐regulated in wounded cutaneous tissue and promotes repair‐associated angiogenesis. However, little is known about its role in lymphatic regeneration of the healing skin. We studied wound healing in transgenic mice that overexpress VEGF‐A specifically in the epidermis and in wild‐type mice in the absence or presence of inhibitors of VEGF‐A signaling. Surprisingly, transgenic overexpression of VEGF‐A in the skin promoted lymphangiogenesis at the wound healing site, whereas systemic blockade of VEGFR‐2 prevented lymphatic vessel formation. Studies in cultured lymphatic endothelial cells revealed that VEGF‐A induced expression of the α1 and α2 integrins, which promoted their in vitro tube formation and their haptotactic migration toward type I collagen. VEGF‐A‐induced lymphatic endothelial cord formation and haptotactic migration were suppressed by anti‐α1 and anti‐α2 integrin blocking antibodies, and systemic blockade of the α1 and α2 integrins inhibited VEGF‐A‐driven lymphangiogenesis in vivo. We propose that VEGF‐A promotes lymphatic vasculature formation via activation of VEGFR‐2 and that lineage‐specific differences of integrin receptor expression contribute to the distinct dynamics of wound‐associated angiogenesis and lymphangiogenesis.

Vismodegib in patients with advanced basal cell carcinoma (STEVIE): a pre-planned interim analysis of an international, open-label trial.

BACKGROUND The Hedgehog pathway inhibitor vismodegib has shown clinical benefit in patients with advanced basal cell carcinoma and is approved for treatment of patients with advanced basal cell carcinoma for whom surgery is inappropriate. STEVIE was designed to assess the safety of vismodegib in a situation similar to routine practice, with a long follow-up. METHODS In this multicentre, open-label trial, adult patients with histologically confirmed locally advanced basal cell carcinoma or metastatic basal cell carcinoma were recruited from regional referral centres or specialist clinics. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and adequate organ function. Patients with locally advanced basal cell carcinoma had to have been deemed ineligible for surgery. All patients received 150 mg oral vismodegib capsules once a day on a continuous basis in 28-day cycles. The primary objective was safety (incidence of adverse events until disease progression or unacceptable toxic effects), with assessments on day 1 of each treatment cycle (28 days) by principal investigator and coinvestigators at the site. Efficacy variables were assessed as secondary endpoints. The safety evaluable population included all patients who received at least one dose of study drug. Patients with histologically confirmed basal cell carcinoma who received at least one dose of study drug were included in the efficacy analysis. An interim analysis was pre-planned after 500 patients achieved 1 year of follow-up. This trial is registered with ClinicalTrials.gov, number NCT01367665. The study is still ongoing. FINDINGS Between June 30, 2011, and Nov 6, 2014, we enrolled 1227 patients. At clinical cutoff (Nov 6, 2013), 499 patients (468 with locally advanced basal cell carcinoma and 31 with metastatic basal cell carcinoma) had received study drug and had the potential to be followed up for 12 months or longer. Treatment was discontinued in 400 (80%) patients; 180 (36%) had adverse events, 70 (14%) had progressive disease, and 51 (10%) requested to stop treatment. Median duration of vismodegib exposure was 36·4 weeks (IQR 17·7-62·0). Adverse events happened in 491 (98%) patients; the most common were muscle spasms (317 [64%]), alopecia (307 [62%]), dysgeusia (269 [54%]), weight loss (162 [33%]), asthenia (141 [28%]), decreased appetite (126 [25%]), ageusia (112 [22%]), diarrhoea (83 [17%]), nausea (80 [16%]), and fatigue (80 [16%]). Most adverse events were grade 1 or 2. We recorded serious adverse events in 108 (22%) of 499 patients. Of the 31 patients who died, 21 were the result of adverse events. As assessed by investigators, 302 (66·7%, 62·1-71·0) of 453 patients with locally advanced basal cell carcinoma had an overall response (153 complete responses and 149 partial responses); 11 (37·9%; 20·7-57·7) of 29 patients with metastatic basal cell carcinoma had an overall response (two complete responses, nine partial responses). INTERPRETATION This study assessed the use of vismodegib in a setting representative of routine clinical practice for patients with advanced basal cell carcinoma. Our results show that treatment with vismodegib adds a novel therapeutic modality from which patients with advanced basal cell carcinoma can benefit substantially. FUNDING F Hoffmann-La Roche.

Tumor Lymphangiogenesis and Metastasis to Lymph Nodes Induced by Cancer Cell Expression of Podoplanin

The membrane glycoprotein podoplanin is expressed by several types of human cancers and might be associated with their malignant progression. Its exact biological function and molecular targets are unclear, however. Here, we assessed the relevance of tumor cell expression of podoplanin in cancer metastasis to lymph nodes, using a human MCF7 breast carcinoma xenograft model. We found that podoplanin expression promoted tumor cell motility in vitro and, unexpectedly, increased tumor lymphangiogenesis and metastasis to regional lymph nodes in vivo, without promoting primary tumor growth. Importantly, high cancer cell expression levels of podoplanin correlated with lymph node metastasis and reduced survival times in a large cohort of 252 oral squamous cell carcinoma patients. Based on comparative transcriptional profiling of tumor xenografts, we identified endothelin-1, villin-1, and tenascin-C as potential mediators of podoplanin-induced tumor lymphangiogenesis and metastasis. These unexpected findings identify a novel mechanism of tumor lymphangiogenesis and metastasis induced by cancer cell expression of podoplanin, suggesting that reagents designed to interfere with podoplanin function might be developed as therapeutics for patients with advanced cancer.

Dimethylfumarate Impairs Melanoma Growth and Metastasis

Dimethylfumarate (DMF) inhibits signals transmitted by Rel proteins and is used for the treatment of inflammatory skin diseases such as psoriasis, but potential effects of DMF on tumor progression have yet not been analyzed. We show that DMF reduced melanoma growth and metastasis in severe combined immunodeficient mouse models. To identify targets of DMF action, we analyzed mRNA expression in DMF-treated melanomas by gene chip arrays. Using BiblioSphere software for data analysis, significantly regulated genes were mapped to Gene Ontology terms cell death, cell growth, and cell cycle. Indeed, we found that DMF inhibited proliferation of human melanoma cells A375 and M24met in vitro. The cell cycle was arrested at the G(2)-M boundary. Moreover, DMF was proapoptotic, as shown by cell cycle analysis and by Annexin V and Apo2.7 staining. These results were confirmed in vivo. DMF reduced proliferation rates of tumor cells as assessed by Ki-67 immunostaining and increased apoptosis as assessed by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling staining. In conclusion, DMF is antiproliferative and proapoptotic and reduces melanoma growth and metastasis in animal models.

Erlotinib and Bevacizumab Have Synergistic Activity against Melanoma

Purpose: Melanoma is one of the most aggressive types of cancer with currently no chance of cure once the disease has spread to distant sites. Therapeutic options for advanced stage III and IV are very limited, mainly palliative, and show response in only ∼20% of all cases. The presented preclinical study was done to investigate the influence of a combined treatment of the epidermal growth factor receptor inhibitor erlotinib and the vascular endothelial growth factor monoclonal antibody bevacizumab in melanoma. Experimental Design and Results: The epidermal growth factor receptor was expressed in all cell lines tested, and treatment with erlotinib did inhibit the activation of the MEK/extracellular signal-regulated kinase and AKT signaling pathways. Whereas in vitro no influence on tumor cell proliferation was seen with erlotinib or bevacizumab monotherapy, a decreased invasive potential on erlotinib treatment in a three-dimensional Matrigel assay was observed. Furthermore, both drugs inhibited proliferation and sprouting of endothelial cells. In vivo, in a severe combined immunodeficient mouse xenotransplantation model, reduction in tumor volume under combined treatment with erlotinib and bevacizumab was superior to the additive effect of both single agents. This was associated with reduced cell proliferation, increased apoptosis, and a reduction in tumor angiogenesis compared with control or single treatment groups. Likewise, the reduction in the extent of lymph node and lung metastasis was most pronounced in animals treated with both drugs. Conclusion: The presented data strongly support the use of a combination of erlotinib and bevacizumab as a novel treatment regimen for metastatic melanoma.

Entering a New Era of Rational Biomarker Discovery for Early Detection of Melanoma Metastases: Secretome Analysis of Associated Stroma Cells

Metastasis in melanoma is associated with poor prognosis. Early detection may thus substantially improve patient survival. Here we present a novel biomarker discovery strategy based on proteome profiling and secretome analysis of primary cells. Tumor associated stroma cells secrete proteins that may act as powerful tumor promoters. This cell cooperativity is reversible and may thus be directly accessible to therapeutic intervention. The onset of these characteristic events seems to precede tumor progression. Thus, proteins specifically secreted by these cells may serve as early disease biomarkers. Due to the leaky nature of newly formed blood vessels and the increased hydrostatic pressure within tumors, secreted proteins are most plausibly shed into the blood. Our analysis strategy is based on three different model systems, including established cultured cell lines, animal model systems, and clinical human samples. The feasibility is demonstrated with secretome and proteome profiles generated from normal human skin fibroblasts in comparison to melanoma-associated fibroblasts isolated from mouse xenografts and fibroblasts from bone marrow of multiple myeloma patients. Further mutual comparisons were enabled including proteome profiles of melanocytes and M24met melanoma cells. All shotgun proteomics data are accessible via the PRIDE database. Among others, the candidate biomarkers GPX5, secreted by melanoma cells, in addition to periostin and stanniocalcin-1, which are expressed by melanoma-associated fibroblasts were identified. In conclusion, this is a novel strategy to identify diagnostic marker proteins aiding early detection of metastatic melanoma and to improve our understanding of pathomechanisms involving the microenvironment to enable the design of novel therapeutic strategies.

The hsp27 kD heat shock protein and p38-MAPK signaling are required for regular epidermal differentiation

BACKGROUND In human epidermal keratinocytes the expression of hsp27 is closely related to differentiation in vitro and in situ. OBJECTIVE We aimed to gain further insight into the role of hsp27 in epidermal differentiation by specific inhibition through siRNA and inhibition of p38-MAPK, the key enzyme of hsp27 phosphorylation. METHODS Normal human keratinocytes (KC) and organotypic skin cultures (SE-skin equivalents) were used. Expression and phosphorylation of hsp27 was inhibited in these models by siRNA and SB203580, a specific inhibitor of p38-MAPK, respectively. Modification of morphology and expression of hsp27 and other differentiation associated proteins was investigated by immunofluorescence, western blot, and RT-PCR. RESULTS Inhibition of p38-MAPK resulted in a downregulation of hsp27 in KC and SE. Additionally, in the presence of SB203580 Ca(2+) induced expression of pro-filaggrin and loricrin was inhibited at the protein level and expression of filaggrin, keratin 10, and transglutaminase 1 at the mRNA level. Addition of SB203580 to SE, as well as hsp27 knockdown in this model resulted in identical patterns of irregular differentiation, disturbance of epidermal layers, and delayed expression of K10. CONCLUSION These results provide evidence that the expression of hsp27 and its phosphorylation by p38-MAPK are required for keratinocyte differentiation and for the formation of a regularly stratified epidermis.

Characterization and Management of Hedgehog Pathway Inhibitor-Related Adverse Events in Patients With Advanced Basal Cell Carcinoma

Vismodegib and sonidegib are Hedgehog pathway inhibitors (HPIs) approved for treatment of patients with advanced basal cell carcinoma. The adverse events (AEs) associated with these therapies can impact clinical outcomes as a result of decreased quality of life and treatment discontinuation. The incidence, clinical presentation, putative mechanisms, and management strategies for AEs related to administration of HPIs are described in this article.

The dermis-prelaminated scapula flap for reconstructions of the hard palate and the alveolar ridge: a clinical and histologic evaluation.

&NA; Ideal reconstructions of complex defects in the midface require the restitution not only of bone and soft tissue, but also of a thin and durable lining of the oral cavity. So far, split‐thickness skin grafts, intestinal grafts, and in vitro cultured mucosal grafts have been used for the reconstruction of the oral lining. The use of skin as a substitute for oral mucosa is controversial because contraction, hair growth, maceration, and dysplastic changes can occur. This clinical and histologic study was performed to evaluate the suitability of dermis as a substitute for oral lining. Twelve complex defects of the midface were reconstructed with dermis‐prelaminated scapula flaps. A bony flap from the lateral border of the scapula was prepared, and osseointegrated implants were placed. The bone flap was then prelaminated with dermis and covered with a Gore‐Tex membrane to prevent adhesions. The composite flap was transferred to the midface 2 to 3 months later. The oral lining of the flap was evaluated clinically and histologically at 2, 4, and 6 weeks and at 3 to 41 months after the reconstruction. In all patients, the reconstructed bone was covered with a thin and lubricated surface without hair growth. None of the patients showed any signs of maceration. Histologically, these findings corresponded to a keratinized stratified squamous epithelium with highly developed connective‐tissue papillae. These features closely resemble those of the normal mucosa of the hard palate and the gingiva. Thus, dermis prelamination is an effective method for reconstructing the mucosa of the alveolar ridge and the hard palate. (Plast. Reconstr. Surg. 108: 1519, 2001.)