22 research outputs found
An Integrated Structural and Computational Study of the Thermostability of Two Thioredoxin Mutants from Alicyclobacillus acidocaldarius
We report a crystallographic and computational analysis of two mutant forms of the Alicyclobacillus acidocaldarius thioredoxin (BacTrx) done in order to evaluate the contribution of two specific amino acids to the thermostability of BacTrx. Our results suggest that the thermostability of BacTrx may be modulated by mutations affecting the overall electrostatic energy of the protein
Diagnostic Consideration for Sinonasal Wegener’s Granulomatosis Clinically Mistaken for Carcinoma
We report a case of Wegener’s granulomatosis clinically mistaken for carcinoma in a 21-year-old girl presenting with an ulcerated mass of the nasopharynx associated with enlarged laterocervical nodes. The lesion was clinically suspected as malignant on the basis of clinical and radiological findings (namely, computed tomography scan and positron emission tomography). However, multiple biopsies were not conclusive for malignancy showing histological change suggestive of Wegener’s granulomatosis. A serum determination of cANCA supported the diagnosis of Wegener’s granulomatosis. Clinical findings and image studies suggested an erroneous diagnosis of malignancy whereas a definitive diagnosis of Wegener’s granulomatosis was achieved only after repeated biopsies thus leading to a correct therapeutic approach. The Wegener granulomatosis must be added to the list of the differential diagnoses of the masses of the nasopharynx associated with or without enlarged laterocervical nodes
Ovarian Clear Cell Carcinoma: From Morphology to Molecular Biology
Ovarian clear cell carcinoma (oCCC) is a distinctive subtype of ovarian carcinoma, with peculiar genetic and environmental risk factors, precursor lesions, molecular events during oncogenesis, patterns of spread, and response to treatment. Because of low response to chemotherapy and poor prognosis in advanced stages, there is growing interest in investigating the molecular pathways involved in oCCC development, in order to individualize novel/molecular targeted therapies. Until now, the main molecular genetic changes associated with oCCC remain to be identified, and, although several molecular changes have been reported in clear cell tumors, most studies have analyzed a limited number of cases; therefore, the true prevalence of those changes is not known. The present review will present the clinicopathologic features of oCCC, from morphology to molecular biology, discussing the diagnostic and treatment challenges of this intriguing ovarian carcinoma
Uncommon frame-shift exon 19 EGFR mutations are sensitive to EGFR tyrosine kinase inhibitors in non-small cell lung carcinoma
Exons 19â\u80\u9321 EGFR activating mutations are predictive biomarkers of response to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC). However, uncommon exon 19 EGFR mutations, due to their low frequency, have an uncertain biological and clinical significance and very little is known about their TKI sensitivity. This study was designed to describe the TKI sensitivity of a small cohort of lung adenocarcinomas bearing uncommon exon 19 mutations and to evaluate in silico the correlation between frame-shift exon 19 mutations and EGFR sequence/structure modification. Among 1168 NSCLCs screened for EGFR mutational status in our Institutions between 2011 and 2016, seven uncommon exon 19 EGFR mutations were further evaluated: five complex mutations, characterized by a deletion followed by a single-nucleotide insertion, a macrodeletion of 25 bp, and a 19 bp duplication. Interestingly, three patients harboring frame-shift mutations (i.e., one complex mutation, the macrodeletion, and the duplication) showed disease stability and considerably long PFS and OS upon TKI therapy. By contrast, three patients with in-frame complex deletions, independently of the mutation starting point, showed poor/lack of response to TKI therapy. In silico structural analysis showed that sensitivity to TKIs correlates with structural changes in the length and conformation of EGFR C-helix in frame-shift mutations. These data suggest that not all uncommon exon 19 EGFR mutations have the same TKI sensitivity and that frame-shift mutations are responsive to TKIs therapy
Polymorphisms of the CYP1A1, CYP2E1 and XRCC1 genes and cancer risk in a Southern Italian population: a case-control study
Polymorphisms in genes encoding enzymes involved in xenobiotic metabolism and/or in cellular defenses against carcinogen-induced DNA damage play an important role in determining individual cancer susceptibility. However, their distribution and association with cancer susceptibility can vary in different populations
FOXL2 molecular status in adult granulosa cell tumors of the ovary: A study of primary and metastatic cases
Granulosa cell tumors (GCTs) of the ovary are uncommon neoplasms, accounting for ~5% of all malignant ovarian tumors. GCTs are a relatively homogeneous group of tumors, categorized into two distinct subtypes, juvenile GCT and adult GCT (AGCT), likely arising from a limited set of molecular events usually involving the disruption of pathways that regulate granulosa cell proliferation. In the present study, the presence of forkheadbox L2 (FOXL2) c.402C>G mutation was investigated in a series of 42 samples of primary and metastatic AGCT of the ovary. The samples consisted of 37 primary and 5 metastatic ovarian AGCTs from 37 patients. FOXL2 mutational status was evaluated using a pyrosequencing approach on 2.5\u2011\ub5m sections of formalin\u2011fixed paraffin\u2011embedded tissue. FOXL2 c.402C>G mutation was found in 33/37 (89.2%) primary AGCTs and in 4/5 (80.0%) metastases, with the molecular status of the metastases recapitulating that of the primary tumors (4 mutated cases and 1 wild\u2011type case). Overall, FOXL2 mutation is present in the majority of primary and metastatic AGCTs, and could be used as a valid tool in the diagnosis of the disease and in cases of metastatic lesions from an unknown primary origin. Moreover the concordance of FOXL2 molecular status in primary and associated metastases suggests its early appearance and genomic stability in AGCT tumorigenesis
Molecular status of PI3KCA, KRAS and BRAF in ovarian clear cell carcinoma: An analysis of 63 patients
Aims To evaluate the incidence of PI3KCA, KRAS and BRAF mutations in primary ovarian clear cell carcinoma (OCCC). Methods 63 consecutive patients, with a proven diagnosis of OCCC, according to WHO criteria, were included into the study. Pyrosequencing analysis of all three genes hotspot regions were performed on 2.5â €...μm sections of formalin-fixed paraffin-embedded tissue from primary OCCC. Results PI3KCA mutations were found in 20/63 (32%) cases; KRAS mutations were found in 8/63 (13%); no BRAF V600 mutations were found. In particular, 12/20 mutations (60%) of PI3KCA were found in the exon 20, whereas the remaining eight cases presented mutations in exon 9 (8/20; 40%). KRAS pyrosequencing analysis revealed higher incidence of codon 12 mutations (7/8; 90%) than codon 13 mutations (1/8; 10%). In five cases (5/66; 8%), synchronous mutations, affecting PI3KCA and KRAS genes, were found. No differences were found in the distribution of hotspot mutations, according to the stage. Conclusions The high frequency of PI3KCA mutations, the low rate of mutations in KRAS and the absence of mutations in BRAF, indicate a molecular signature of OCCCs different from other ovarian carcinomas. Detection of driver mutations, such as PI3KCA and KRAS, may be the basis for a targeted therapy, although the clinical and therapeutic implications of these findings have to be supported by further studies
A Pilot Characterization of Human Lung NSCLC by Protein Pathway Activation Mapping
Abstract: Background: An understanding of the activated protein signaling architecture in non-small-cell lung cancer (NSCLC) is of critical importance to the development of new therapeutic approaches and identification of predictive and prognostic biomarkers for patient stratification.
Methods: We used reverse-phase protein microarrays to map the activated protein signaling networks of 47 NSCLC tumors, 28 of which were node negative, which were subjected to tumor cellular enrichment using laser capture microdissection. The phosphorylation/cleavage levels of 111 key signaling proteins and total levels of 17 proteins were measured for broadscale signaling analysis.
Results: Pathway activation mapping of NSCLC revealed distinct subgroups composed of epidermal growth factor receptor (ERBB1), v-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2), v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ERBB3), v-erb-a erythroblastic leukemia viral oncogene homolog 4 (ERBB4), v-akt murine thymoma viral oncogene homolog 1-mammalian target of rapamycin (AKT-mTOR), protein kinase, AMP-activated, alpha 2 catalytic subunit (AMPK), and autophagy-related signaling, along with transforming growth factor-beta-signaling protein 1 (SMAD), insulin-line growth factor receptor (IGFR), rearranged during transfection proto-oncogene (RET), and activated CDC42-associated kinase (ACK) activation. Investigation of epidermal growth factor receptor (EGFR)-driven signaling identified a unique cohort of tumors with low EGFR protein expression yet high relative levels of phosphorylated EGFR and high EGFR total protein with low relative levels of phosphorylation. Last, mapping analysis of patients with NSCLC with N0 disease revealed a pilot pathway activation signature composed of linked epidermal growth factor receptor family (HER)-AMPK-AKT-mTOR signaling network along with focal adhesion kinase-LIM domain kinase-1 (FAK-LIMK) and janus kinase (JAK)-signal transducers and activators of transcription (STAT) pathways that correlated with short-term survival and aggressive disease.
Conclusions: Functional protein pathway activation mapping of NSCLC reveals distinct activation subgroups that are underpinned by important therapeutic targets and that patients with early-stage node negative disease and poor prognosis may be identified by activation of defined, biochemically linked protein signaling events. Such findings, if confirmed in larger study sets, could help select and stratify patients for personalized targeted therapies