A Systemic Complete Response of Metastatic Melanoma to Local Radiation and Immunotherapy

BACKGROUND: Melanoma is a relatively immunogenic tumor, in which infiltration of melanoma cells by T lymphocytes is associated with a better clinical prognosis. We hypothesized that radiation-induced cell death may provide additional stimulation of an anti-tumor immune response in the setting of anti-CTLA-4 treatment. METHODS: In a pilot melanoma patient, we prospectively tested this hypothesis. We treated the patient with two cycles of ipilimumab, followed by stereotactic ablative radiotherapy to two of seven hepatic metastases, and two additional cycles of ipilimumab. RESULTS: Subsequent positron emission tomography-computed tomography scan indicated that all metastases, including unirradiated liver lesions and an unirradiated axillary lesion, had completely resolved, consistent with a complete response by RECIST. CONCLUSION: The use of radiotherapy in combination with targeted immunotherapy as a noninvasive in vivo tumor vaccine strategy appears to be a promising method of enhancing the induction of systemic immune responses and anti-tumor effect.     

The Prognostic Significance of Metabolic Response Heterogeneity in Metastatic Colorectal Cancer

Background

Tumoral heterogeneity is a major determinant of resistance in solid tumors. FDG-PET/CT can identify early during chemotherapy non-responsive lesions within the whole body tumor load. This prospective multicentric proof-of-concept study explores intra-individual metabolic response (mR) heterogeneity as a treatment efficacy biomarker in chemorefractory metastatic colorectal cancer (mCRC).

Methods

Standardized FDG-PET/CT was performed at baseline and after the first cycle of combined sorafenib (600mg/day for 21 days, then 800mg/day) and capecitabine (1700 mg/m²/day administered D1-14 every 21 days). MR assessment was categorized according to the proportion of metabolically non-responding (non-mR) lesions (stable FDG uptake with SUVmax decrease <15%) among all measurable lesions.

Results

Ninety-two patients were included. The median overall survival (OS) and progression-free survival (PFS) were 8.2 months (95% CI: 6.8–10.5) and 4.2 months (95% CI: 3.4–4.8) respectively. In the 79 assessable patients, early PET-CT showed no metabolically refractory lesion in 47%, a heterogeneous mR with at least one non-mR lesion in 32%, and a consistent non-mR or early disease progression in 21%. On exploratory analysis, patients without any non-mR lesion showed a significantly longer PFS (HR 0.34; 95% CI: 0.21–0.56, P-value <0.001) and OS (HR 0.58; 95% CI: 0.36–0.92, P-value 0.02) compared to the other patients. The proportion of non-mR lesions within the tumor load did not impact PFS/OS.

Conclusion

The presence of at least one metabolically refractory lesion is associated with a poorer outcome in advanced mCRC patients treated with combined sorafenib-capecitabine. Early detection of treatment-induced mR heterogeneity may represent an important predictive efficacy biomarker in mCRC.

Trial Registration

ClinicalTrials.gov NCT01290926     

Elimination of Metastatic Melanoma Using Gold Nanoshell-Enabled Photothermal Therapy and Adoptive T Cell Transfer

Ablative treatments such as photothermal therapy (PTT) are attractive anticancer strategies because they debulk accessible tumor sites while simultaneously priming antitumor immune responses. However, the immune response following thermal ablation is often insufficient to treat metastatic disease. Here we demonstrate that PTT induces the expression of proinflammatory cytokines and chemokines and promotes the maturation of dendritic cells within tumor-draining lymph nodes, thereby priming antitumor T cell responses. Unexpectedly, however, these immunomodulatory effects were not beneficial to overall antitumor immunity. We found that PTT promoted the infiltration of secondary tumor sites by CD11b⁺Ly-6G/C⁺ myeloid-derived suppressor cells, consequently failing to slow the growth of poorly immunogenic B16-F10 tumors and enhancing the growth of distant lung metastases. To exploit the beneficial effects of PTT activity against local tumors and on antitumor immunity whilst avoiding the adverse consequences, we adoptively transferred gp100-specific pmel T cells following PTT. The combination of local control by PTT and systemic antitumor immune reactivity provided by adoptively transferred T cells prevented primary tumor recurrence post-ablation, inhibited tumor growth at distant sites, and abrogated the outgrowth of lung metastases. Hence, the combination of PTT and systemic immunotherapy prevented the adverse effects of PTT on metastatic tumor growth and optimized overall tumor control.     

转移性结直肠癌抗血管生成靶向治疗的研究进展

近年来,由于各种新的化疗药物及分子靶向药物的使用,转移性结直肠癌(metastatic colorectal cancer,m CRC)的个体化治疗逐步取得了重要的成果。研究表明,抗血管生成靶向药物与化疗药物的联合使用作为转移性结直肠癌的一线治疗方案,可明显改善治疗效果,延长患者的生存时间。血管内皮生长因子(vascularendothelial growth factor,VEGF)是肿瘤血管生成过程中最主要的因子。贝伐单抗是通过基因工程技术得到的针对血管内皮生长因子-A(VEGF-A)的单克隆抗体,作为抗血管生成靶向药物用于转移性结直肠癌的临床治疗。本文对近年来转移性结直肠癌的抗血管生成靶向治疗,尤其是贝伐单抗治疗的相关研究进展进行综述并展望未来抗血管生成靶向治疗的发展前景。     

Gene Network Rewiring to Study Melanoma Stage Progression and Elements Essential for Driving Melanoma

Metastatic melanoma patients have a poor prognosis, mainly attributable to the underlying heterogeneity in melanoma driver genes and altered gene expression profiles. These characteristics of melanoma also make the development of drugs and identification of novel drug targets for metastatic melanoma a daunting task. Systems biology offers an alternative approach to re-explore the genes or gene sets that display dysregulated behaviour without being differentially expressed. In this study, we have performed systems biology studies to enhance our knowledge about the conserved property of disease genes or gene sets among mutually exclusive datasets representing melanoma progression. We meta-analysed 642 microarray samples to generate melanoma reconstructed networks representing four different stages of melanoma progression to extract genes with altered molecular circuitry wiring as compared to a normal cellular state. Intriguingly, a majority of the melanoma network-rewired genes are not differentially expressed and the disease genes involved in melanoma progression consistently modulate its activity by rewiring network connections. We found that the shortlisted disease genes in the study show strong and abnormal network connectivity, which enhances with the disease progression. Moreover, the deviated network properties of the disease gene sets allow ranking/prioritization of different enriched, dysregulated and conserved pathway terms in metastatic melanoma, in agreement with previous findings. Our analysis also reveals presence of distinct network hubs in different stages of metastasizing tumor for the same set of pathways in the statistically conserved gene sets. The study results are also presented as a freely available database at http://bioinfo.icgeb.res.in/m3db/. The web-based database resource consists of results from the analysis presented here, integrated with cytoscape web and user-friendly tools for visualization, retrieval and further analysis.     

Contrast-Enhanced CT Density Predicts Response to Sunitinib Therapy in Metastatic Renal Cell Carcinoma Patients

The first-line therapy in metastatic renal cell carcinoma (mRCC), sunitinib, exhibits an objective response rate of approximately 30%. Therapeutic alternatives such as other tyrosine kinase inhibitors, VEGF inhibitors, or mTOR inhibitors emphasize the clinical need to predict the patient's response to sunitinib therapy before treatment initiation. In this study, we evaluated the prognostic value of pretreatment portal venous phase contrast-enhanced computed tomography (CECT) mean tumor density on overall survival (OS), progression-free survival (PFS), and tumor growth in 63 sunitinib-treated mRCC patients. Higher pretreatment CECT tumor density was associated with longer PFS and OS [hazard ratio (HR) = 0.968, P = .002, and HR = 0.956, P = .001, respectively], and CECT density was inversely correlated with tumor growth (P = .010). Receiver operating characteristic analysis identified two CECT density cut-off values (63.67 HU, sensitivity 0.704, specificity 0.694; and 68.67 HU, sensitivity 0.593, specificity 0.806) which yielded subpopulations with significantly different PFS and OS (P < .001). Pretreatment CECT is therefore a promising noninvasive strategy for response prediction in sunitinib-treated mRCC patients, identifying patients who will derive maximum therapeutic benefit.     

Molecular Markers of Tumor Progression in Melanoma

Malignant melanoma represents one of the most aggressive malignancies but outcome is highly variable with early tumor lesions having an excellent prognosis following resection. We review here the data on identification of genes involved in the progression of melanoma as a result of expression array studies, genomic profiling, and genetic models. We focus on the role of tumor suppressors involved in cell cycle function, DNA repair, and genome maintenance. Highlighted are the roles of loss of p16 in promoting neoplasia in cooperation with deregulated MAPK signaling, and the role of loss of the RASSF1A protein in promoting chromosomal instability. The interactions between point mutation in growth signaling molecules and epigenetic changes in genes involved in DNA repair and cell division are discussed.Key Words: Melanoma, genetic progression, tumor suppressors, cell cycle, alkylating agents, mitotic spindle, mitotic spindle poisons.     

Dacarbazine Combined Targeted Therapy versus Dacarbazine Alone in Patients with Malignant Melanoma: A Meta-Analysis

Background

Malignant melanoma is the most aggressive and deadly form of skin cancer. Dacarbazine (DTIC) has been the approved first-line treatment for metastatic melanoma in routine clinical practice. However, response rates with single-agent DTIC are low. The objective of this study was to compare the efficacy and safety of DTIC with or without placebo and DTIC-based combination therapies in patients with advanced metastatic melanoma.

Methods

We searched from electronic databases such as The Cochrane Library, MEDLINE, EBSCO, EMBASE, Ovid, CNKI, and CBMDisc from 2003 to 2013. The primary outcome measures were overall response and 1-year survival, and the secondary outcome measurements were adverse events.

Results

Nine randomized controlled trials (RCTs) involving 2,481 patients were included in the meta-analysis. DTIC-based combination therapies was superior to DTIC alone in overall response (combined risk ratio [RR]  = 1.60, 95% confidence interval [CI]: 1.27–2.01) and 1-year survival (combined RR = 1.26, 95% CI: 1.14–1.39). Patients with DTIC-based combination therapies had higher incidence of adverse events including nausea (combined RR = 1.23, 95% CI: 1.10–1.36), vomiting (combined RR = 1.73, 95% CI: 1.41–2.12) and neutropenia (combined RR = 1.75, 95% CI: 1.42–2.16) compared to the group for DTIC alone.

Conclusion

These data suggested that DTIC-based combination therapies could moderately improve the overall response and the 1-year survival but increased the incidence of adverse events. Further large-scale, high-quality, placebo-controlled, double-blind trials are needed to confirm this conclusion.     

Mechanical Properties of Growing Melanocytic Nevi and the Progression to Melanoma

Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma in a way that is still unclear from the biochemical and genetic point of view. Diagnostic and prognostic tools are then mostly based on dermoscopic examination and morphological analysis of histological tissues. To investigate the role of mechanics and geometry in the morpholgical dynamics of melanocytic nevi, we study a computation model for cell proliferation in a layered non-linear elastic tissue. Numerical simulations suggest that the morphology of the nevus is correlated to the initial location of the proliferating cell starting the growth process and to the mechanical properties of the tissue. Our results also support that melanocytes are subject to compressive stresses that fluctuate widely in the nevus and depend on the growth stage. Numerical simulations of cells in the epidermis releasing matrix metalloproteinases display an accelerated invasion of the dermis by destroying the basal membrane. Moreover, we suggest experimentally that osmotic stress and collagen inhibit growth in primary melanoma cells while the effect is much weaker in metastatic cells. Knowing that morphological features of nevi might also reflect geometry and mechanics rather than malignancy could be relevant for diagnostic purposes.     

Investigation of Inter- and Intratumoral Heterogeneity of Glioblastoma Using TOF-SIMS

1. Download : Download high-res image (127KB)
2. Download : Download full-size image

Highlights

• •TOF-SIMS allows to visualize normal brain and tumor border.
• •Glioma samples can be subdivided into clinically relevant groups by TOF-SIMS data.
• •TOF-SIMS allows to simultaneously detect proteins and metabolites in clinical samples.

     

Analysis of BRAF Mutation in Primary and Metastatic Melanoma

Mutation of BRAF has been proposed to contribute to melanoma development. However, it remains unclear whether or not BRAF mutation is associated with any particular stage of melanoma progression. Tumor biopsy specimens from patients with melanoma were analyzed to determine whether the frequency of BRAF mutation in metastatic melanoma differed from primary melanoma. BRAF mutation was present in 15 of 23 (61%) patients with primary melanoma and in 7 of 12 (58%) patients with metastatic melanoma. These results suggest that BRAF mutation in melanoma is most likely to occur prior to the development of metastatic disease.     

A Novel Stratification Method in Linkage Studies to Address Inter- and Intra-Family Heterogeneity in Autism

Most genome linkage scans for autism spectrum disorders (ASDs) have failed to be replicated. Recently, a new ASD phenotypic sub-classification method was developed which employed cluster analyses of severity scores from the Autism Diagnostic Interview-Revised (ADI-R). Here, we performed linkage analysis for each of the four identified ADI-R stratified subgroups. Additional stratification was also applied to reduce intra-family heterogeneity and to investigate the impact of gender. For the purpose of replication, two independent sets of single nucleotide polymorphism markers for 392 families were used in our study. This deep subject stratification protocol resulted in 16 distinct group-specific datasets for linkage analysis. No locus reached significance for the combined non-stratified cohort. However, study-wide significant (P = 0.02) linkage scores were reached for chromosomes 22q11 (LOD = 4.43) and 13q21 (LOD = 4.37) for two subsets representing the most severely language impaired individuals with ASD. Notably, 13q21 has been previously linked to autism with language impairment, and 22q11 has been separately associated with either autism or language disorders. Linkage analysis on chromosome 5p15 for a combination of two stratified female-containing subgroups demonstrated suggestive linkage (LOD = 3.5), which replicates previous linkage result for female-containing pedigrees. A trend was also found for the association of previously reported 5p14-p15 SNPs in the same female-containing cohort. This study demonstrates a novel and effective method to address the heterogeneity in genetic studies of ASD. Moreover, the linkage results for the stratified subgroups provide evidence at the gene scan level for both inter- and intra-family heterogeneity as well as for gender-specific loci.     

Key Role of Apoptosis in Uveal Melanoma Progression

Apoptosis is known as a major achievement of biological evolution aimed at eliminating genetic waste, transformed or deteriorated cells, and hence at controlling neoplastic processes. At the same time, clinical data point to an inverse effect. Thorough fundamental studies at the levels of light and electron microscopy allowed us to reveal several disturbances in the physiological course of apoptosis. We discuss possible recruitment of this mechanism by a tumor in order to self-select a cell clone with the highest malignant potential and eliminate less aggressive populations in which the set of point mutations is abortive for further tumor progression.     

Functional Characterization of Stromal Osteopontin in Melanoma Progression and Metastasis

Background

Recent studies demonstrated that not only tumor derived- but stroma derived factors play crucial role in cancer development. Osteopontin (OPN) is a secreted non-collagenous, sialic acid rich, chemokine-like phosphoglycoprotein that facilitates cell-matrix interactions and promotes tumor progression. Elevated level of OPN has been shown in melanoma patient and predicted as a prognostic marker. Recent reports have indicated that stroma-derived OPN are involved in regulating stem cell microenvironment and pre-neoplastic cell growth. However, the function of stroma derived OPN in regulation of side population (SP) enrichment leading to melanoma growth, angiogenesis and metastasis is not well studied and yet to be the focus of intense investigation.

Methodology/Principal Findings

In this study, using melanoma model, in wild type and OPN knockout mice, we have demonstrated that absence of host OPN effectively curbs melanoma growth, angiogenesis and metastasis. Melanoma cells isolated from tumor of OPN wild type (OPN^+/+) mice exhibited more tumorigenic feature as compared to the parental cell line or cells isolated from the tumors of OPN KO (OPN^−/−) mice. Furthermore, host OPN induces VEGF, ABCG2 and ERK1/2 expression and activation in B16-WT cells. We report for the first time that stroma derived OPN regulates SP phenotype in murine melanoma cells. Moreover, loss in and gain of function studies demonstrated that stroma-derived OPN regulates SP phenotype specifically through ERK2 activation.

Conclusions

This study establish at least in part, the molecular mechanism underlying the role of host OPN in melanoma growth and angiogenesis, and better understanding of host OPN-tumor interaction may assist the advancement of novel therapeutic strategy for the management of malignant melanoma.     

Electrophoretic Heterogeneity of Pigmented Hamster Melanoma Cells

Pigmented hamster melanoma tumors growing in situ contain two subpopulations of melanoma cells that have different electrophoretic mobilities (EPM). A mild neuraminidase treatment, which removes sialic acid residues from the cell surface glycoproteins, reduces the EPM of both groups of melanoma cells yielding an electrophoretically uniform population. This shows that the differences in the EPM between the subpopulations of pigmented melanoma cells stem from the different content of sialic acid residues on the cell surface. The relationship between the different EPM melanoma cell subpopulations was, therefore, examined during tumor growth, development, and formation of metastases. The relative content of cells having high electrophoretic mobility, the “fast moving” cells, increases as the tumors grow larger. However, tumors of the same diameter contain nearly the same fraction of “fast moving” cells despite their age. The proportion of the “fast moving” cells is significantly higher in the central part than in the outermost layer of pigmented melanoma tumors. These data suggest that the development of “fast moving” cells is promoted by some size-dependent changes in the intratumor environment. In vivo selection of melanoma cells for their ability to colonize lungs renders tumors that reveal elevated metastatic potential and contain a significantly higher fraction of cells possessing high electrophoretic mobility than the parent tumor. Moreover, the metastatic nodules contain a remarkably elevated fraction of the “fast moving” cells. The reported correlation between the “fast moving” cell fraction and the metastatic potential suggests that the relative content of cells having high electrophoretic mobility may determine the metastaticity of pigmented hamster melanoma.     

Development of Allogeneic NK Cell Adoptive Transfer Therapy in Metastatic Melanoma Patients: In Vitro Preclinical Optimization Studies

Natural killer (NK) cells have long been considered as potential agents for adoptive cell therapy for solid cancer patients. Until today most studies utilized autologous NK cells and yielded disappointing results. Here we analyze various modular strategies to employ allogeneic NK cells for adoptive cell transfer, including donor-recipient HLA-C mismatching, selective activation and induction of melanoma-recognizing lysis receptors, and co-administration of antibodies to elicit antibody-dependent cell cytotoxicity (ADCC). We show that NK cell activation and induction of the relevant lysis receptors, as well as co-administration of antibodies yield substantial anti-cancer effects, which are functionally superior to HLA-C mismatching. Combination of the various strategies yielded improved effects. In addition, we developed various clinically-compatible ex vivo expansion protocols that were optimized according to fold expansion, purity and expression of lysis receptors. The main advantages of employing allogeneic NK cells are accessibility, the ability to use a single donor for many patients, combination with various strategies associated with the mechanism of action, e.g. antibodies and specific activation, as well as donor selection according to HLA or CD16 genotypes. This study rationalizes a clinical trial that combines adoptive transfer of highly potent allogeneic NK cells and antibody therapy.     

Novel Somatic Mutations to PI3K Pathway Genes in Metastatic Melanoma

Background

BRAF^V600 inhibitors have offered a new gateway for better treatment of metastatic melanoma. However, the overall efficacy of BRAF^V600 inhibitors has been lower than expected in clinical trials, and many patients have shown resistance to the drug’s effect. We hypothesized that somatic mutations in the Phosphoinositide 3-Kinase (PI3K) pathway, which promotes proliferation and survival, may coincide with BRAF^V600 mutations and contribute to chemotherapeutic resistance.

Methods

We performed a somatic mutation profiling study using the 454 FLX pyrosequencing platform in order to identify candidate cancer genes within the MAPK and PI3K pathways of melanoma patients. Somatic mutations of theses candidate cancer genes were then confirmed using Sanger sequencing.

Results

As expected, BRAF^V600 mutations were seen in 51% of the melanomas, whereas NRAS mutations were seen in 19% of the melanomas. However, PI3K pathway mutations, though more heterogeneous, were present in 41% of the melanoma, with PTEN being the highest mutated PI3K gene in melanomas (22%). Interestingly, several novel PI3K pathway mutations were discovered in MTOR, IRS4, PIK3R1, PIK3R4, PIK3R5, and NFKB1. PI3K pathway mutations co-occurred with BRAF^V600 mutations in 17% of the tumors and co-occurred with 9% of NRAS mutant tumors, implying cooperativity between these pathways in terms of melanoma progression.

Conclusions

These novel PI3K pathway somatic mutations could provide alternative survival and proliferative pathways for metastatic melanoma cells. They therefore may be potential chemotherapeutic targets for melanoma patients who exhibit resistance to BRAF^V600 inhibitors.     

Non-Invasive Imaging Provides Spatiotemporal Information on Disease Progression and Response to Therapy in a Murine Model of Multiple Myeloma

Background

Multiple myeloma (MM) is a B-cell malignancy, where malignant plasma cells clonally expand in the bone marrow of older people, causing significant morbidity and mortality. Typical clinical symptoms include increased serum calcium levels, renal insufficiency, anemia, and bone lesions. With standard therapies, MM remains incurable; therefore, the development of new drugs or immune cell-based therapies is desirable. To advance the goal of finding a more effective treatment for MM, we aimed to develop a reliable preclinical MM mouse model applying sensitive and reproducible methods for monitoring of tumor growth and metastasis in response to therapy.

Material and Methods

A mouse model was created by intravenously injecting bone marrow-homing mouse myeloma cells (MOPC-315.BM) that expressed luciferase into BALB/c wild type mice. The luciferase in the myeloma cells allowed in vivo tracking before and after melphalan treatment with bioluminescence imaging (BLI). Homing of MOPC-315.BM luciferase+ myeloma cells to specific tissues was examined by flow cytometry. Idiotype-specific myeloma protein serum levels were measured by ELISA. In vivo measurements were validated with histopathology.

Results

Strong bone marrow tropism and subsequent dissemination of MOPC-315.BM luciferase⁺ cells in vivo closely mimicked the human disease. In vivo BLI and later histopathological analysis revealed that 12 days of melphalan treatment slowed tumor progression and reduced MM dissemination compared to untreated controls. MOPC-315.BM luciferase⁺ cells expressed CXCR4 and high levels of CD44 and α4β1 in vitro which could explain the strong bone marrow tropism. The results showed that MOPC-315.BM cells dynamically regulated homing receptor expression and depended on interactions with surrounding cells.

Conclusions

This study described a novel MM mouse model that facilitated convenient, reliable, and sensitive tracking of myeloma cells with whole body BLI in living animals. This model is highly suitable for monitoring the effects of different treatment regimens.