Amber L. Shada

Comprehensive analysis of receptor tyrosine kinase activation in human melanomas reveals autocrine signaling through IGF-1R.

Melanomas depend on autocrine signals for proliferation and survival; however, no systematic screen of known receptor tyrosine kinases (RTKs) has been performed to identify which autocrine signaling pathways are activated in melanoma. Here, we performed a comprehensive analysis of 42 RTKs in six individual human melanoma tumor specimens as well as 17 melanoma cell lines, some of which were derived from the tumor specimens. We identified five RTKs that were active in almost every one of the melanoma tissue specimens and cell lines, including two previously unreported receptors, insulin-like growth factor receptor 1 (IGF-1R) and macrophage-stimulating protein receptor (MSPR), in addition to three receptors (vascular endothelial growth factor receptor, fibroblast growth factor receptor, and hepatocyte growth factor receptor) known to be autocrine activated in melanoma. We show, by quantitative real time PCR, that all melanoma cell lines expressed genes for the RTK ligands such as HGF, IGF-1, and MSP. Addition of antibodies to either IGF-1 or HGF, but not to MSP, to the culture medium blocked melanoma cell proliferation, and even caused net loss of melanoma cells. Antibody addition deactivated IGF-1R and hepatocyte growth factor receptors, as well as mitogen-activated protein kinase signaling. Thus, IGF-1 is a new growth factor for autocrine driven proliferation of human melanoma in vitro. Our results suggest that IGF-1—IGF-1R autocrine pathway in melanoma is a possible target for therapy in human melanomas.

Clinical activity and safety of combination therapy with temsirolimus and bevacizumab for advanced melanoma: a phase II trial (CTEP 7190/Mel47).

Purpose: A CTEP-sponsored phase II trial was conducted to evaluate safety and clinical activity of combination therapy with CCI-779 (temsirolimus) and bevacizumab in patients with advanced melanoma. Experimental Design: Patients with unresectable stage III to IV melanoma were treated intravenously with temsirolimus 25 mg weekly and bevacizumab 10 mg every 2 weeks. Adverse events were recorded using CTCAE v3.0. Tumor response was assessed by Response Evaluation Criteria in Solid Tumors and overall survival was recorded. Correlative studies measured protein kinases and histology of tumor biopsies and immune function in peripheral blood. Results: Seventeen patients were treated. Most patients tolerated treatment well, but 2 had grade 4 lymphopenia and 1 developed reversible grade 2 leukoencephalopathy. Best clinical response was partial response (PR) in 3 patients [17.7%, 90% confidence interval (CI) 5, 0–39.6], stable disease at 8 weeks (SD) in 9 patients, progressive disease (PD) in 4 patients, and not evaluable in 1 patient. Maximal response duration for PR was 35 months. Ten evaluable patients had BRAFWT tumors, among whom 3 had PRs, 5 had SD, and 2 had PD. Correlative studies of tumor biopsies revealed decreased phospho-S6K (d2 and d23 vs. d1, P < 0.001), and decreased mitotic rate (Ki67+) among melanoma cells by d23 (P = 0.007). Effects on immune functions were mixed, with decreased alloreactive T-cell responses and decreased circulating CD4+FoxP3+ cells. Conclusion: These data provide preliminary evidence for clinical activity of combination therapy with temsirolimus and bevacizumab, which may be greater in patients with BRAFwt melanoma. Mixed effects on immunologic function also support combination with immune therapies. Clin Cancer Res; 19(13); 3611–20. ©2013 AACR.

Amelanotic melanomas presenting as red skin lesions: a diagnostic challenge with potentially lethal consequences

Objective To characterize epidemiologic and clinical features of red primary amelanotic melanomas, an atypical presentation of melanoma that is underemphasized in patient and physician education.

Outcome of sentinel lymph node biopsy and prognostic implications of regression in thin malignant melanoma.

Thin melanomas with partial or complete regression may provide clues about antitumor immunity, but their management remains controversial. We have characterized the management and clinical outcomes of regressed thin (<1 mm) T1a melanomas and hypothesized that regression increases the risk of regional metastases when compared with nonregressed thin melanomas. A prospectively collected clinical database was reviewed, and T1a melanomas with regression were identified. Histology, surgical approach, outcome, and survival were evaluated. The primary outcome measures were sentinel node positivity, subsequent lymph node metastasis, and survival. A total of 75 patients with T1a or in-situ melanomas were grouped into three subsets. Group 1: 35 underwent a sentinel node biopsy (SNBx), none of which were positive. No patients developed nodal recurrence. The 5-year survival of this group was 93%, with a median follow-up of 52 months. Group 2: 31 were followed up without SNBx; two developed regional nodal disease (6.5%), neither of whom died of subsequent distant disease. The 5-year survival was 89%, with a median follow-up of 38 months. There was no significant difference in the survival between groups 1 and 2. Group 3: nine patients presented with metastatic disease concurrent with a regressed thin melanoma. These patients had a median survival of 2.3 years and a 4-year survival estimate of 22%. Regression should not be used as an indication for SNBx in T1a melanomas; we recommend that such patients be managed with wide local excision and a long-term clinical follow-up. The poor prognosis of thin regressed primary melanoma with simultaneous metastatic disease may indicate the existence of immune escape phenotypes supporting melanoma progression.

MicroRNAs induced in melanoma treated with combination targeted therapy of Temsirolimus and Bevacizumab.

BackgroundTargeted therapies directed at commonly overexpressed pathways in melanoma have clinical activity in numerous trials. Little is known about how these therapies influence microRNA (miRNA) expression, particularly with combination regimens. Knowledge of miRNAs altered with treatment may contribute to understanding mechanisms of therapeutic effects, as well as mechanisms of tumor escape from therapy. We analyzed miRNA expression in metastatic melanoma tissue samples treated with a novel combination regimen of Temsirolimus and Bevacizumab. Given the preliminary clinical activity observed with this combination regimen, we hypothesized that we would see significant changes in miRNA expression with combination treatment.MethodsUsing microarray analysis we analyzed miRNA expression levels in melanoma samples from a Cancer Therapy Evaluation Program-sponsored phase II trial of combination Temsirolimus and Bevacizumab in advanced melanoma, which elicited clinical benefit in a subset of patients. Pre-treatment and post-treatment miRNA levels were compared using paired t-tests between sample groups (patients), using a p-value < 0.01 for significance.ResultsmicroRNA expression remained unchanged with Temsirolimus alone; however, expression of 15 microRNAs was significantly upregulated (1.4 to 2.5-fold) with combination treatment, compared to pre-treatment levels. Interestingly, twelve of these fifteen miRNAs possess tumor suppressor capabilities. We identified 15 putative oncogenes as potential targets of the 12 tumor suppressor miRNAs, based on published experimental evidence. For 15 of 25 miRNA-target mRNA pairings, changes in gene expression from pre-treatment to post-combination treatment samples were inversely correlated with changes in miRNA expression, supporting a functional effect of those miRNA changes. Clustering analyses based on selected miRNAs suggest preliminary signatures characteristic of clinical response to combination treatment and of tumor BRAF mutational status.ConclusionsTo our knowledge, this is the first study analyzing miRNA expression in pre-treatment and post-treatment human metastatic melanoma tissue samples. This preliminary investigation suggests miRNAs that may be involved in the mechanism of action of combination Temsirolimus and Bevacizumab in metastatic melanoma, possibly through inhibition of oncogenic pathways, and provides the preliminary basis for further functional studies of these miRNAs.

Two patients with hailey-hailey disease, multiple primary melanomas, and other cancers

BACKGROUND Hailey-Hailey Disease (HHD) is an autosomal dominant skin disorder that is characterized by erythematous and sometimes vesicular, weeping plaques of intertriginous regions. Squamous cell carcinoma and basal cell carcinoma arising in lesions of HHD have been described in the literature. To our knowledge, there are no reports of melanoma or noncutaneous malignant neoplasms associated with HHD. OBSERVATIONS We discuss the mechanisms of oncogenicity, including genetic, environmental, and iatrogenic factors, in 2 patients with HHD, multiple primary melanomas, and other cancers. Patient 1 had a mucoepidermoid carcinoma of the parotid gland. Patient 2 had a history of acute monoblastic leukemia and malignant peripheral nerve sheath tumor as well as radiologic evidence of an acoustic neurilemmoma. CONCLUSIONS The cause of the cancers in these 2 patients is likely multifactorial. We describe the patients to draw attention to the possible association between HHD and cancer. Additional research should be performed to determine whether patients with HHD have an increased incidence of cancer.

Interface of Signal Transduction Inhibition and Immunotherapy in Melanoma

Food and Drug Administration-approved treatment for metastatic melanoma, including interferon alpha and interleukin-2, offer a modest benefit. Immunotherapy, although has not enjoyed high overall response rates, is capable of providing durable responses in a subset of patients. In recent years, new molecular-targeted therapies have become available and offer promise of clinical benefit, although low durability of response. It is not yet clear how best to integrate these 2 novel modalities that target the immune response to melanoma (immune therapy) or that target molecular signaling pathways in the melanoma cells (targeted therapy). Many signal transduction pathways are important in both tumor cell and T-cell proliferation and survival, which generate risk in combining targeted therapy and immunotherapy. This review focuses on the role of targeted therapy and immunotherapy in melanoma, and discusses how to combine the 2 modalities rationally for increased duration and response.

Endoluminal Negative-Pressure Therapy for Preventing Rectal Anastomotic Leaks: A Pilot Study in a Pig Model

BACKGROUND Anastomotic leak after rectal resection carries substantial morbidity and mortality. A diverting ileostomy is beneficial for high-risk anastomoses, but its creation and reversal carry a surgical risk in addition to that of resection itself. We sought an alternative method for managing complications of rectal anastomosis. METHODS We developed an endoluminal negative-pressure technology with a diverting proximal sump, and hypothesized that it would close anastomotic disruptions in pigs. We performed rectal resections on pigs, with primary anastomoses and the creation of an anastomotic defect. In animals in the treatment group we inserted an endoluminal negative-pressure device and kept it at a low level of continuous suction for 5 d. No device was inserted in a control group of animals. After the 5-d period of treatment we evaluated the anastomoses in both the treatment and control groups of animals for leakage, using contrast enemas. Specimens of anastomosed rectum were evaluated histologically for mucosal integrity and for the location and density of inflammatory responses. RESULTS Fourteen pigs were assigned to either the treatment (n=10) or control (n=4) group. Of the pigs in the treatment group, 90% had complete closure of their rectal defect, as compared with 25% of the animals in the control group (χ(2) test, p=0.04). The animals in the treatment group had only minimal mucosal and serosal inflammation, whereas those in the control group had extensive mucosal damage with associated serositis. CONCLUSIONS Endoluminal negative-pressure therapy was well-tolerated and led to successful closure of 90% of the anastomic rectal defects in the treatment group of animals in the present study. Additional evaluation of this therapy is warranted.

Surgical resection for bulky or recurrent axillary metastatic melanoma.

Metastatic melanoma has few FDA approved treatments, and aggressive surgical resection has to be considered for management of bulky axillary metastases. We hypothesized that axillary resection in this setting is well tolerated and improves symptoms in the majority of patients.

Delayed Endoluminal Vacuum Therapy for Rectal Anastomotic Leaks after Rectal Resection in a Swine Model: A New Treatment Option

Anastomotic leaks are a dreaded surgical complication following colorectal operations. Creation of a temporary proximal diverting ileostomy is used in high‐risk anastomoses, however, additional surgical risk is accumulated with its creation and reversal. Endoluminal vacuum therapy has been shown to seal anastomotic defects in the prophylactic setting in a pig model and we hypothesized it could be utilized in a delayed fashion to rescue subjects with an active anastomotic leak. Yorkshire pigs underwent rectal resection, intentional leak confirmed by fluoroscopy, and endoluminal vacuum therapy device placement to low continuous suction. Following treatment, a contrast enema and necropsy was performed for gross and histopathology. Pigs underwent 2 (or 5) days of free intraperitoneal leak prior to device placement and 5 (or 7) subsequent days of endoluminal vacuum therapy. Six of seven early‐treated pigs sealed their anastomotic defect, while two of the four treated pigs in this extended group sealed the defect. Endoluminal vacuum therapy is feasible and well tolerated in a pig model, and it has been shown to seal a significant number of freely leaking anastomoses in the early period (86%). This technology warrants further study as it may provide a noninvasive means to treatment of anastomotic leaks.