Targeting HER2 is effective in 24% of ERBB2 amplified metastatic colorectal cancer; however, secondary resistance occurs in most of the cases. We studied the evolution of individual metastases during treatment to discover spatially resolved determinants of resistance. Circulating tumor DNA (ctDNA) analysis identified alterations associated with resistance in the majority of refractory patients. ctDNA profiles and lesion-specific radiographic reports revealed organ- or metastasis-private evolutionary patterns. When radiologic assessments documented progressive disease in target lesions, response to HER2 blockade was retained in other metastases. Genomic and functional analyses on samples and cell models from eight metastases of a patient co-recruited to a postmortem study unveiled lesion-specific evolutionary trees and pharmacologic vulnerabilities. Lesion size and contribution of distinct metastases to plasma ctDNA were correlated.
To identify gene expression changes in melanocytic lesions, biopsies from 18 common nevi (CMN), 11 dysplastic nevi (DN), 8 radial and 15 vertical growth phase melanomas (RGPM, VGPM), and 5 melanoma metastases (MTS) were analyzed using whole genome microarrays. The comparison between CMN and RGPM showed an enrichment of Gene Ontology terms related to inter and intracellular junctions, whereas the transition from RGPM to VGPM underlined the alteration of apoptosis. Upregulation of genes involved in dsDNA break repair and downregulation of cellular adhesion genes were observed in MTS with respect to VGPM. DN exhibited rather heterogeneous molecular profiles, with some proliferation genes expressed at higher levels than in CMN, altered regulation of transcription compared to RGPM and a subset of processes, such as mismatch repair, equally expressed as in VGPM. Furthermore, the expression profile of genes involved into cellular detoxification and antigen presentation split them into two classes, with different proliferation potential. Finally, molecular profiling of individual lesions identified altered biological processes, such as regulation of apoptosis, regulation of transcription and T-cell activation, not associated with specific histological classes but rather with subgroups of samples without apparent relationship. This holds true for dysplastic nevi in particular. Our data indicate that generally the intersection between stage specific and sample specific molecular alterations may lead to a more precise determination of the individual progression risk of melanocytic lesions.Malignant cutaneous melanoma originates in melanocytes, the pigment-producing cells of the skin and eye. This entity is relatively rare compared with other skin cancers (<5%), but is still responsible for 80% of all skin cancer-related deaths. Early-stage melanoma is a curable disease if properly excised, whereas the life span of patients with advanced disease is relatively short, and little progress has been made in the treatment of metastatic melanoma. 1 Moreover, there are no available markers to predict which early stage tumors have a high progression risk. 2 The initiation and progression of melanoma is characterized by a sequence of cytoarchitectural modifications and by stromal (dermis and subcutis) invasion, on which the Clark's method of microstaging is based. 3 The driving force behind those processes is the acquisition of somatic mutations in key regulatory genes. The vertical growth phase, which involves the escape from keratinocyte-mediated growth control, is the most critical event along this progression. 4 Gene expression profiling utilizing microarrays is an efficient method to discover altered molecular mechanisms and allows detection of the expression levels of thousands of genes in one experiment. 5 The most relevant studies conducted to define the transcriptional changes occurring during melanoma progression have recently been described in a comprehensive review. 6 However, the majority of these studies have been carri...
For the first time, the intense killing activity of CIK cells against autologous metastatic melanoma, including mCSCs, has been shown. These findings move clinical investigation of a new immunotherapy for metastatic melanoma, including mCSCs, closer.
Gastric cancer is the world's third leading cause of cancer mortality. In spite of significant therapeutic improvements, the clinical outcome for patients with advanced gastric cancer is poor; thus, the identification and validation of novel targets is extremely important from a clinical point of view. We generated a wide, multilevel platform of gastric cancer models, comprising 100 patient-derived xenografts (PDX), primary cell lines, and organoids. Samples were classified according to their histology, microsatellite stability, Epstein-Barr virus status, and molecular profile. This PDX platform is the widest in an academic institution, and it includes all the gastric cancer histologic and molecular types identified by The Cancer Genome Atlas. PDX histopathologic features were consistent with those of patients' primary tumors and were maintained throughout passages in mice. Factors modulating grafting rate were histology, TNM stage, copy number gain of tyrosine kinases/KRAS genes, and microsatellite stability status. PDX and PDX-derived cells/organoids demonstrated potential use-fulness to study targeted therapy response. Finally, PDX transcriptomic analysis identified a cancer cell-intrinsic microsatellite instability (MSI) signature, which was efficiently exported to gastric cancer, allowing the identification, among microsatellite stable (MSS) patients, of a subset of MSI-like tumors with common molecular aspects and significant better prognosis. In conclusion, we generated a wide gastric cancer PDX platform, whose exploitation will help identify and validate novel "druggable" targets and optimize therapeutic strategies. Moreover, transcriptomic analysis of gastric cancer PDXs allowed the identification of a cancer cell-intrinsic MSI signature, recognizing a subset of MSS patients with MSI transcriptional traits, endowed with better prognosis.Significance: This study reports a multilevel platform of gastric cancer PDXs and identifies a MSI gastric signature that could contribute to the advancement of precision medicine in gastric cancer.
BRAFV600E mutation has been frequently reported in different types of melanocytic lesions, but its role in melanomagenesis is poorly understood, having been associated with either the proliferative-induced MAPK pathway activation or the acquisition of oncogene-driven senescence. The presence of BRAF alterations has been related to sun exposure, although the molecular mechanisms underlying this event are only partly known. To elucidate the relationships among BRAF/NRAS alterations, MAPK pathway activation, and sun exposure, we examined 22 acquired nevi and 18 cutaneus melanomas from 38 patients. Microdissected tissues from each lesion were subjected to BRAF/NRAS mutation analysis by sequencing, allele-specific PCR and pyrosequencing assay. The same lesions were also examined for the expression of phosphorylated ERK1/2. Phototype and an accurate history of sun exposure were evaluated for each patient. BRAF V600E mutation was detected in 50% of the acquired nevi and in 70% of the cutaneus melanomas in the absence of NRAS alterations. The fraction of alleles carrying BRAF V600E substitution was variable but strongly associated with sun exposure. In contrast, no relationship was evidenced between the presence of this mutation and patients' phototype, phosphorylated ERK1/2 expression, or Clark's level. Our findings indicate that in melanocytic lesions, BRAF V600E mutation can affect a subset of the cells and is associated with the type and quantity of sun exposure. This mutation is independent of the nevo-melanoma progression and unrelated to ERK phosphorylation, suggesting that alternative mechanisms to the MAPK activation are also involved in this type of transformation.
We aimed to study the prevalence of thyroid autoimmunity in infertile women; to assess whether thyroid autoantibodies were associated with non-organ-specific autoantibodies; and to investigate the influence of this dysfunction on the couples' chances of pregnancy. We assayed serum levels of thyroid stimulating hormone (TSH), free thyroxine, and microsomal and thyroglobulin autoantibodies in 149 infertile women. In patients with serum TSH levels in the hypothyroid or hyperthyroid range and/or with thyroid autoantibodies, we performed thyroid ultrasound examinations and assayed some non-organ-specific autoantibodies. We compared the duration of infertility in infertile patients with normal thyroid (control group), with thyroid abnormalities, and with thyroid autoantibodies in euthyroidism. Thirty infertile patients (20.1%) had thyroid abnormalities. The prevalence of thyroid autoantibodies was 17.4%. In infertile patients with thyroid autoantibodies, we found a poor association with non-organ-specific autoantibodies. Only the women with thyroid abnormalities and ovulatory dysfunction had a mean duration of infertility significantly longer than that of the control group. When the data were analyzed for euthyroid women with thyroid autoantibodies, we found no significant variation in the duration of infertility. Although we found a high prevalence of thyroid autoantibodies in infertile patients, the presence of these autoantibodies per se did not reduce the chance of pregnancy.
SUMMARY:Familial adenomatous polyposis (FAP) is an autosomal dominant condition characterized by the development of hundreds to thousands of colorectal adenomatous polyps. In addition to the classic form, there is also attenuated polyposis (attenuated adenomatous polyposis coli; AAPC), which is characterized by a milder phenotype. FAP/AAPC is caused by germline mutations in the adenomatous polyposis coli (APC) gene. Very recently, germline mutations in the base-excision repair gene MYH have been associated with recessive inheritance of multiple colorectal adenomas in a subset of patients. APC pathogenic alterations are mostly (Ͼ95%) represented by frameshift or nonsense mutations leading to the synthesis of a truncated protein.We identified 20 APC truncating mutation carriers out of 30 FAP/AAPC patients from different Italian kindreds. In the remaining 10 patients, we searched for alterations other than truncating mutations by enzymatic mutation detection, real-time quantitative RT-PCR, and genotyping of polymorphic markers encompassing the APC locus. Moreover, to assess whether mutations of genes interacting with APC can substitute or act in association with APC alterations, we sequenced both CTNNB1 (-catenin) and CDH1 (E-cadherin) genes. No CTNNB1 or CDH1 mutations were found. On the contrary, four patients showed a reduced APC gene expression compared with healthy subjects. In three of the four cases, genotyping results were compatible with a constitutive allelic deletion. In one case this conclusion was confirmed by haplotype segregation analysis. Our results support the notion that FAP/AAPC can result from APC constitutive haploinsufficiency, with gene deletion being a possible cause of reduced gene expression. (Lab Invest 2003, 83:1859 -1866.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.