Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One of the least commonly encountered spindle cell tumors seen on prostatic needle biopsy or transurethral resection (TUR) of the prostate is solitary fibrous tumor (SFT). We studied 13 cases of SFTs identified on either prostate needle biopsy (n=9) or TUR of the prostate (n=4). Mean patient age at diagnosis was 63 years (range: 46 to 75 y; median: 65 y). Twelve men presented with urinary tract symptoms and 1 patient was biopsied during work-up of bone metastases. Ten cases were SFTs originating in the prostate, 2 cases arose between the prostate and rectum extending into the prostate (n=2), and 1 case was a pelvic mass without infiltration of the prostate. In 9 cases, a complete tumor resection was attempted by cystoprostatectomy (n=2), radical prostatectomy (n=4), pelvic exenteration (n=2), or pelvic tumor resection (n=1). Enucleation (n=1) and TUR (n=1) were performed in 2 other cases. Tumor sizes ranged from 8.5 to 15 cm in 7 radically resected cases. Mitotic rates were 3 to 5 per 10 high power fields in 5 cases, with the remaining cases having either rare (n=4) or no mitoses (n=4). Seven cases demonstrated areas of necrosis. Based on a combination of increased cellularity, mitotic activity, necrosis, nuclear pleomorphism, and infiltrativeness, 4 prostatic SFTs were malignant, 4 were benign, and 2 were borderline. Of the 3 non-prostatic SFTs, 1 was malignant and 2 were borderline. All tumors but 1 were immunoreactive for CD34 (n=12). Material for additional immunohistochemistry was available for the majority of cases with positive stains for Bcl-2 (11/11), CD99 (7/10), beta-catenin (5/10), and c-kit (0/11). Three SFTs demonstrated >or=10% p53 immunoreactivity including 1 tumor with 50% positivity; and 3 cases had Ki-67 rates of >or=20%. Although all SFTs were initially clinically considered to be of prostatic origin, some of the cases arose in the pelvis with secondary involvement of the prostate. Approximately 50% of prostatic SFTs were malignant. Even in the prostatic and nonprostatic SFTs with no overt malignant features, sometimes it was necessary to remove the prostate and in some instances the adjacent organs because of the large size of the tumors. SFTs must be differentiated from other spindle cell neoplasms of the prostate especially from gastrointestinal stromal tumors that may arise from the rectal wall with invasion of the prostate or from the region between the rectum and the prostate.
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PMID:Solitary fibrous tumor on needle biopsy and transurethral resection of the prostate: a clinicopathologic study of 13 cases. 1752 73

Light, electron microscopy, polymerase chain reaction (PCR), and immunohistochemistry were used to reveal the proliferative, alterative processes of hepatic parenchymal cells, P 53, K-ras, B-raf, c-Kit, p 16, APC, immunoreactive proteins Ki-67, cytokeratins 9, 14, 20, EMA, c-erb B-2, CD-117, mutated p 53 and bcl-2 genes. P53, K-ras, B-raf, c-Kit, and p 16 gene mutations were detected in the liver of animals with experimental superinvasive opisthorchiasis (SO) and cholangiocellular carcinoma (CCC). Mutations of these genes were found in the plasma samples taken from SO patients. The CCC tissue from SO patients displayed expression of the following genes: p 53 (100.0%), p 53+B-raf (50.0%), K-ras+c-Kit (33.3%), K-ras+B-rafat more than 5 cm from the tumor in 2 cases. Following 2 years, target therapy (canglait, megamin, immunomodulators) leveled mutations in 91.25% of the patients with SO.
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PMID:[Molecular genetic approaches in parasitology (in case of opisthorchiasis)]. 1766 39

Neuroblastoma (NB) is the most common malignant solid tumor in childhood. There are well-recognized prognostic factors in NB such as age at diagnosis, organ of origin, stages, MYCN gene amplification, and expression of H-ras, trkA and survivin. Moreover, we investigated the expression of vascular endothelial growth factor (VEGF), tyrosine hydroxylase (TH), p53, stem cell factor (SCF) and c-kit of its receptor with quantitative real-time polymerase chain reaction (PCR) in 22 NBs and 4 other tumors (one malignant lymphoma, one malignant teratoma, and 2 rhabdomyosarcomas) samples. The correlation between patients' prognoses and the expression of TH or c-kit was newly recognized, particularly the good prognosis in patients in whom c-kit highly expressed and the poor prognosis contrarily associated with low or no expression, although the SCF of its ligand had no relationship with patient prognosis. It is possible that tumors without c-kit expression can not react with SCF (via the autocrine or paracrine system) and remain immature. It may be that this is a new critical clinical event in NB patients.
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PMID:Analyses of novel prognostic factors in neuroblastoma patients. 1805 15

High-grade transformation of adenoid cystic carcinoma (ACC) (previously referred to as dedifferentiation) is a rare phenomenon that does not fit into the traditional ACC grading schemes. The importance and minimal criteria for distinction from solid (grade III) ACC are not well established. We report 11 new cases and review the literature to further define the profile of this tumor. The median age was 61 years (range: 32 to 72 y) with a male predominance (male to female ratio of 1.75:1). The most commonly involved sites were sinonasal (4/11) and submandibular (4/11). Lymph nodes were pathologically positive in 4/7 (57.1%) cases. Distant metastases to the lung (n=2) and soft tissue of the shoulder (n=1) were observed. Five of 9 patients (55.6%) died, all within 5 years with a median overall survival of 12 months. Histologically, ACC with high-grade transformation was distinguished from conventional ACC by nuclear enlargement and irregularity, higher mitotic counts, and the loss of the biphasic ductal-myoepithelial differentiation. Useful supportive criteria were prominent comedonecrosis and fibrocellular desmoplasia. The most common morphologies for the high-grade component were poorly differentiated cribriform adenocarcinoma and solid undifferentiated carcinoma. Micropapillary and squamoid patterns were occasionally present. Ki-67 and p53 labeling indices were elevated in the high-grade components, though c-kit and cyclin-D1 were not. ACC-high-grade transformation is a highly aggressive salivary gland tumor with a variety of histologic patterns. The high propensity for lymph node metastases suggests a role for neck dissection in patients with this rare tumor.
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PMID:Adenoid cystic carcinoma with high-grade transformation: a report of 11 cases and a review of the literature. 1805 25

Although the exact molecular mechanisms of Merkel cell carcinoma (MCC) tumorigenesis are unknown, they likely involve complex genetic alterations and mutations similar to those seen in many other cancers. In this study, we obtained MCCs from 21 elderly patients (19 women, 2 men) and analyzed their DNA for mutation of exons of interest in several tumor-suppressor genes or oncogenes known to be frequently mutated in skin cancer: p53 (exons 4-8), Ras (exons 1 and 2), c-Kit (exon 11), and the INK4a-ARF locus (encoding p14 and p16) (exons 1 and 2). Direct sequence analysis revealed p53 mutations (that is, at codons 224, 234, and 294) in three tumors (14%) and p16INK4a mutations (that is, at codon 6) in one (5%). No mutations were detected in Ha-Ras, Ki-Ras, N-Ras, c-Kit, or p14ARF. On the other hand, methylation-specific PCR revealed methylation of p14ARF promoter DNA in eight of 19 analyzable tumor samples (42%) and p16INK4a promoter DNA in one of 19 analyzable tumor samples (5%). Together, these findings suggest that p14ARF silencing may be an important mechanism in MCC tumorigenesis, and thus a potential target for therapeutic intervention in this highly aggressive tumor type.
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PMID:p14ARF hypermethylation is common but INK4a-ARF locus or p53 mutations are rare in Merkel cell carcinoma. 1821 79

Microglandular adenosis (MGA) of the breast is widely known as a benign lesion that can mimic invasive carcinoma. In situ and invasive carcinomas have been described as arising in MGA, but which cases of MGA will progress to carcinoma is unclear. Criteria for distinguishing uncomplicated MGA, MGA with atypia (AMGA), and carcinoma arising in MGA (MGACA) are not standardized. The primary objective of this study was to illustrate the clinical, histopathologic, and immunophenotypical characteristics of MGA, AMGA, and MGACA in an effort to provide criteria for distinguishing the 3 types. We retrospectively identified 108 cases seen at M.D. Anderson Cancer Center between 1983 and 2007 that had a diagnosis of MGA. Of the 108 cases, 65 cases had available material for review. Inclusion criteria were glands of MGA expressing S-100 protein and lacking myoepithelial layer (smooth muscle actin negative). Eleven out of 65 cases qualified to have an MGA component; myoepithelial layer was detected in the remaining 54 cases and were classified as adenosis. Out of the 11 MGA patients, there were 3 patients with uncomplicated MGA, 2 had AMGA, and 6 had MGACA. Staining indices for the cell cycle markers p53 and Ki-67 were used to compare the 3 tumor categories. Additional staining for other tumor markers [estrogen and progesterone receptors, HER2, epidermal growth factor receptor (EGFR), c-kit, CK5/6, and CK18] were performed. Patient demographics, tumor radiologic features, and clinical follow-up data were collected for all cases. Multiple invasive histologic components were identified in each of the MGACA cases. All invasive MGACAs had a duct-forming component. In addition, basal-like component was present in 2 cases, aciniclike in 2, matrix producing in 4, sarcomatoid in 1, and adenoid cystic in 1. All tumors had strong and diffuse CK8/18 and EGFR expression but no estrogen receptor, progesterone receptor, HER2 (ie, triple negative), or CK5/6 expression. C-kit was focally expressed in 2 of the MGACAs. Ki-67 and p53 labeling indices was < 3% in all MGAs, 5% to 10% in the AMGAs, and > 30% in MGACAs. In a follow-up ranging from 14 days to 8 years, none of the MGA cases recurred. One of the AMGA cases recurred as invasive carcinoma in a background of AMGA after 8 years following incomplete excision of the lesion. Three out of 6 MGACA cases (50%) required multiple consecutive resections ending up with mastectomy due to involved margins by invasive or in situ carcinoma. Two out of 6 MGACA cases (34%) developed metastasis and died of disease. Our data showed that Ki-67 and p53 expression, in conjunction with the morphologic features, could be a reliable marker to distinguish MGA from AMGA and MGACA. Although 11 tumors were only included in our study, 64% of the tumors were carcinomas arising in MGA. This high incidence of MGACA may not represent the actual frequency of MGAs progressing into carcinoma and is likely due to referral bias in our institution. Nonetheless, the high association of carcinoma with MGA necessitates complete excision of MGA to rule out invasion. Although all the MGACA cases were triple negative and express EGFR (basal-like features), all the cases in our study showed a luminal type of differentiation by CK8/18 expression, indicating that MGACA may not fit well into the current proposed molecular classification of breast cancer.
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PMID:Clinical, histopathologic, and immunohistochemical features of microglandular adenosis and transition into in situ and invasive carcinoma. 1830 Jul 93

Gastrointestinal Stromal Tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract, and it is characterized by the occurrence, in > 90 % of cases, of a gain of function mutation in the c-kit proto-oncogene. STI-571 (imatinib mesylate), a selective KIT tyrosine kinase inhibitor, has changed the natural history of this disease, since it has shown high effectiveness in metastatic GIST, and it is currently under investigation also in the adjuvant and neoadjuvant setting. Mechanisms of resistance to imatinib mesylate include both de novo, and, more frequently, acquired resistance, which may occur after several months of drug administration and possibly depends, in most cases, upon an acquired second mutation. In order to overcome imatinib mesylate resistance, the addition of other drugs may be considered in patients who have less than an optimal response to imatinib mesylate monotherapy. Investigational agents that are being studied in this setting include the mammalian target of rapamycin (mTOR) inhibitor RAD 001 and the protein kinase C inhibitor PKC412. In addition, other KIT tyrosine kinase inhibitors with anti-VEGF receptor inhibitory activity, such as SU11248, PTK787/ZK787 and AMG 706, are currently being explored as second line monotherapy for imatinib mesylate-resistant GIST. Finally, another new drug, ecteinascidin (ET-743), that blocks cell cycle progression in G2/M phase through a p53-independent apoptotic mechanism, has shown important preclinical and clinical activity against a number of human solid tumors, including GIST.
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PMID:Medical treatment of gastrointestinal stromal tumors: state of the art and future perspectives. 1839 78

A primary invasive micropapillary carcinoma of the breast in a 46-year-old woman is reported. Histologically, it was composed predominantly of papillary tumor cell clusters without fibrovascular cores, surrounded by a clear space. Tumor cells were positive for cytokeratin (CK) 7, estrogen receptor (ER), and progesterone receptor (PR), but negative for p53, CK 20, CD34, c-Erb-B2, CK5, epidermal growth factor receptor (EGFR), vimentin, and c-kit. MUC1 expression was found at the reversed apical membrane of neoplastic cell clusters. Accordingly, electron microscopy showed the lack of basement membrane and presence of microvilli at the basal surface of the tumor cells. Moreover, ultrastructural examination revealed single tumor cell death characterized by patchy condensations of chromatin throughout the nucleus. These nuclear alterations were associated with the occurrence of empty cytoplasmic vacuoles, conferring a necrosis-like phenotype to this cell death. Alternative programmed cell deaths are reviewed and their morphologic distinction is discussed.
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PMID:Micropapillary carcinoma of the breast with necrosis-like cell death: a case report. 1869 1

Pleuro-pulmonary solitary fibrous tumor (SFT) is a relatively uncommon mesenchymal neoplasm of uncertain histogenesis, unknown molecular features, and unpredictable clinical behavior. Although complete resection is universally accepted as the most important single prognostic factor, some clinicopathologic characteristics (gross appearance, tumor size, mitotic index, tumor necrosis, hypercellularity, and pleomorphism) are related to patient outcome, and a staging system based on these parameters with practical therapeutical implications has been recently proposed by de Perrot et al. Here, 88 pleuro-pulmonary SFTs were collected and clinicopathologic characteristics including de Perrot classification, patients' follow-up, p53 expression, and several "targetable" kinases [c-kit, v-raf murine sarcoma viral oncogene homolog B1, platelet-derived growth factor receptor (PDGFR)-alpha/beta, c-met, epidermal growth factor receptor (EGFR)] were retrospectively analyzed. Fifty-two cases (59%) had at least 1 clinicopathologic feature related to malignancy, whereas mortality and recurrences occurred in 10.2% and 18.2% of the cases, respectively. de Perrot staging and high p53 expression were significantly related to the conventional clinicopathologic prognostic features as well as to overall survival (OS) and disease-free survival (DFS) (P<0.001). At multivariate analysis, high p53 expression and tumor necrosis were the only parameters significantly associated with OS and DFS (P=0.017 and P=0.012, respectively). Immunohistochemical expression was frequently detected for PDGFR-alpha (97.7%), PDGFR-beta (86.5%), and hepatocyte growth factor receptor (96.6%), whereas missense mutations were only identified in 2 cases both involving PDGFR-beta (exons 18 and 20). We conclude that de Perrot stratification of SFT is a reliable prognostic indicator and merits consideration in view of its suggestions for the management of these tumors in daily practice. p53 expression may represent a valid and easy-to-test prognostic factor significantly related to OS and DFS. Although mutations of the corresponding genes are rare events in SFT, PDGFR-alpha/beta, and hepatocyte growth factor receptor tyrosine kinases should be further investigated given the availability of specific inhibitory molecules which might provide useful and novel therapeutical approaches for SFT patients.
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PMID:Pleuro-pulmonary solitary fibrous tumors: a clinicopathologic, immunohistochemical, and molecular study of 88 cases confirming the prognostic value of de Perrot staging system and p53 expression, and evaluating the role of c-kit, BRAF, PDGFRs (alpha/beta), c-met, and EGFR. 1875 43

The author reports a rare case of primary large cystic extragastrointestinal stromal tumor (eGIST) of the transverse mesocolon with genetic analyses of the c-kit and platelet-derived growth factor receptor-alpha (PDGFRA) genes. A 78-year-old man was found to have a large cystic tumor in the abdomen, and the tumor was resected. Grossly, the tumor was located in the transverse mesocolon, and cystic. Microscopically, the tumor consisted of epithelioid cells with atypia. Mitotic figures were noted in five of 50 high power fields. Immunohistochemically, the tumor cells were positive for KIT, CD34, PDGFRA, and vimentin, but negative for cytokeratins, neuron specific enolase, desmin, S100 protein, alpha-smooth muscle actin, p53 protein, HMB45, CD68, CEA, factor VIII-related antigen, chromogranin, and synaptophysin. Ki67 labeling was 5%. Genetically, the tumor showed a point mutation (GAC --> GTC) at codon 842 of exon 18 of the PDGFRA gene. Exon 12 of the PDGFRA gene and exons 9, 11, 13, and 17 of the c-kit gene showed no mutations. No recurrence is noted 3 years after the operation. This case shows that eGIST may occur in the transverse mesocolon.
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PMID:Primary extragastrointestinal stromal tumor of the transverse mesocolon without c-kit mutations but with PDGFRA mutations. 1877 14


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