Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hereditary retinoblastoma patients are at an increased risk for subsequent primary tumors after successful treatment for their initial cancer. Two mechanisms may be responsible for this increased incidence of second malignancies: genetic susceptibility (RB1 gene alterations) and induction by radiation that is frequently used as treatment for retinoblastoma. Because of the high cure rates obtained in the treatment of retinoblastoma, the risk of subsequent primary tumors is substantial, especially in the radiation field. We present four retinoblastoma survivors who developed multiple subsequent primary tumors. Two retinoblastoma survivors developed one and the other two patients two subsequent primary tumors. Despite extensive treatments two patients died of their second primary tumor in the head and neck region. The head and neck surgeon has an increasingly important role in the diagnosis and management of subsequent primary tumors in retinoblastoma survivors.
 ...
PMID:Subsequent tumors in retinoblastoma survivors: the role of the head and neck surgeon. 1828 Jul 73

Pediatric small round cell tumors (SRCT) are a group of neoplasms occurring in children, which have in common a cytomorphology of groups of small round cells with scanty cytoplasm. The common SRCT encountered are neuroblastoma, retinoblastoma, Ewing's sarcoma/peripheral neuroectodermal tumor (PNET), rhabdomyosarcoma and lymphoma which show varying degrees of bone marrow involvement and bone marrow evaluation forms a part of the initial staging procedure. This study was undertaken to evaluate marrow involvement at presentation in pediatric non hematological SRCT. 7833 bone marrow aspirates done over a period of three years in different malignancies were analysed and of these 180 aspirates were performed in patients of pediatric non hematological SRCT at presentation. These cases were evaluated in detail for incidence of marrow involvement. Thirty two (17.7%) cases showed marrow involvement and these cases have been analysed with respect to the primary tumor. The SRCT showing involvement of bone marrow included neuroblastoma (48.8%), retinoblastoma (11.1%), Ewing's sarcoma/PNET (8.6%) and rhabdomyosarcoma (3.2%). These findings are discussed in the light of available world literature.
 ...
PMID:Bone marrow involvement at presentation in pediatric non-haematological small round cell tumours. 1830 98

Patients with hereditary retinoblastoma are at increased risk of second primary tumor, the commonest tumor being osteosarcoma. Leiomyosarcoma developing as second primary neoplasm in retinoblastoma patients is unusual and most have occurred in the field of previous radiotherapy. Although with aggressive therapy better survival can be achieved, the overall prognosis of patients developing these second neoplasms is poor. In this report we present a case of leiomyosarcoma of the maxilla as a second neoplasm in a patient with bilateral retinoblastoma which has developed outside the radiation field.
 ...
PMID:Leiomyosarcoma of the maxilla as second malignancy in retinoblastoma. 1901 17

Retinoblastoma (RB) is the commonest primary intraocular tumor in children. Overexpression of the high mobility group (HMG) A2 protein has been observed in a variety of malignant tumors and often correlates with poor prognosis. We studied the expression of HMGA2 in primary tumor samples and correlated with clinicopathologic features such as invasion, differentiation, and laterality of the tumors. Among 64 tumors, there were 29 tumors with invasion of the optic nerve, choroid, and/or orbit and 35 tumors without invasion. HMGA2 immunoreactivity was evaluated on archival paraffin sections and the results confirmed by Western blotting on 12 fresh tumor samples. Among 29 tumors with invasion, HMGA2 was strongly positive (++) in 10 tumors, moderately positive (+) in 11 tumors. Among 35 tumors without invasion, HMGA2 was strongly positive (++) in 6 tumors, moderately positive (+) in 6 tumors. Tumors with invasion showed significantly higher expression of HMGA2 compared with tumors without invasion (P<0.01). Non-neoplastic retina was negative for HMGA2. There was no correlation between HMGA2 expression and differentiation/laterality. Western blotting revealed that 7 tumors were strongly positive, 2 were moderately positive, and 1 was faintly positive for HMGA2. Our study has demonstrated the HMGA2 expression in a large cohort of primary retinoblastoma tumors and its correlation with invasiveness.
 ...
PMID:Expression of high mobility group A2 protein in retinoblastoma and its association with clinicopathologic features. 1926 51

In the 1970s, several human retinoblastoma cell lines were developed from cultures of primary tumors. As the human retinoblastoma cell lines were established in culture, growth properties and changes in cell adhesion were described. Those changes correlated with the ability of the human retinoblastoma cell lines to invade the optic nerve and metastasize in orthotopic xenograft studies. However, the mechanisms that underlie these changes were not determined. We used the recently developed knockout mouse models of retinoblastoma to begin to characterize the molecular, cellular, and genetic changes associated with retinoblastoma tumor progression and optic nerve invasion. Here we report the isolation and characterization of the first mouse retinoblastoma cell lines with targeted deletions of the Rb family. Our detailed analysis of these cells as they were propagated in culture from the primary tumor shows that changes in cadherin-mediated cell adhesion are associated with retinoblastoma invasion of the optic nerve prior to metastasis. In addition, the same changes in cadherin-mediated cell adhesion correlate with the invasive properties of the human retinoblastoma cell lines isolated decades ago, providing a molecular mechanism for these earlier observations. Most importantly, our studies are in agreement with genetic studies on human retinoblastomas, suggesting that changes in this pathway are involved in tumor progression.
 ...
PMID:Changes in retinoblastoma cell adhesion associated with optic nerve invasion. 1978 71

Retinoblastoma is a relatively rare malignant pediatric tumor accounting for approximately 3% of childhood cancers and 1% of all cancer deaths in children under 15 years of age. During the clinical course of the disease, a metastasis usually occurs within the first year of diagnosis and is seen in 2% of retinoblastoma patients. Metastases to the intracranial region are common and account for approximately 50% of the metastatic cases. Metastasis to the soft tissue is very rare. Herein, we report a case of metastatic retinoblastoma presenting as a left shoulder soft tissue mass in a 14-year-old female with a 14-year history of familial bilateral retinoblastoma status post radiation therapy. In our case, the FNA cytology shows some features of the small round blue cell tumor group with inconspicuous Flexner-Wintersteiner or Homer-Right rosette formation. The unusual clinical presentation and morphology give rise to a diagnostic dilemma, with the differential diagnosis centering on the small round blue cell tumors such as lymphoma, rhabdomyosarcoma, nephroblastoma (Wilms' tumor), Ewing's sarcoma/PNET, and desmoplastic small round cell tumor. It also prompts concern for the development of a second primary tumor. The purpose of our study is to discuss the FNA cytology of metastatic retinoblastoma, its differential diagnoses, and the utility of immunohistochemistry. An accurate diagnosis is imperative due to the differences in prognosis and treatment implications for the various diseases.
 ...
PMID:Metastatic retinoblastoma presenting as a left shoulder soft tissue mass: FNA findings and review of the literature. 1993 45

The RB and p53 tumor suppressors are mediators of DNA damage response, and compound inactivation of RB and p53 is a common occurrence in human cancers. Surprisingly, their cooperation in DNA damage signaling in relation to tumorigenesis and therapeutic response remains enigmatic. In the context of individuals with heritable retinoblastoma, there is a predilection for secondary tumor development, which has been associated with the use of radiation-therapy to treat the primary tumor. Furthermore, while germline mutations of the p53 gene are critical drivers for cancer predisposition syndromes, it is postulated that extrinsic stresses play a major role in promoting varying tumor spectrums and disease severities. In light of these studies, we examined the tumor suppressor functions of these proteins when challenged by exposure to therapeutic stress. To examine the cooperation of RB and p53 in tumorigenesis, and in response to therapy-induced DNA damage, a combination of genetic deletion and dominant negative strategies was employed. Results indicate that loss/inactivation of RB and p53 is not sufficient for cellular transformation. However, these proteins played distinct roles in response to therapy-induced DNA damage and subsequent tumorigenesis. Specifically, RB status was critical for cellular response to damage and senescence, irrespective of p53 function. Loss of RB resulted in a dramatic evolution of gene expression as a result of alterations in epigenetic programming. Critically, the observed changes in gene expression have been specifically associated with tumorigenesis, and RB-deficient, recurred cells displayed oncogenic characteristics, as well as increased resistance to subsequent challenge with discrete therapeutic agents. Taken together, these findings indicate that tumor suppressor functions of RB and p53 are particularly manifest when challenged by cellular stress. In the face of such challenge, RB is a critical suppressor of tumorigenesis beyond p53, and RB-deficiency could promote significant cellular evolution, ultimately contributing to a more aggressive disease.
 ...
PMID:Differential impact of tumor suppressor pathways on DNA damage response and therapy-induced transformation in a mouse primary cell model. 2004 21

Retinoblastoma is the most common primary cancer of the eye in children. The prognosis for survival is excellent. The current therapy includes an improved survival rate and decreased iatrogenic sequelae. The relative risk of a second tumor in survivors of retinoblastoma is documented, especially in those who carry a germline RB mutation. It is strongly increased in case of radiation therapy. The most common types of second primary tumor are sarcoma of soft tissues and osteosarcoma. We present here a rare case of a retinoblastoma patient who received radiation therapy as a part of his treatment and developed a papillar thyroid cancer as a second malignancy. Papillar thyroid cancer has a good prognosis. Systematic screening for thyroid carcinoma should be undertaken in patients irradiated for congenital retinoblastoma.
 ...
PMID:[Papillar thyroid cancer: a rare case of a second primary tumor in retinoblastoma]. 2292 33

Verification that cell lines used for cancer research are derived from malignant cells in primary tumors is imperative to avoid invalidation of study results. Retinoblastoma is a childhood ocular tumor that develops from loss of functional retinoblastoma protein (pRb) as a result of genetic or epigenetic changes that affect both alleles of the RB1 gene. These patients contain unique identifiable genetic signatures specifically present in malignant cells. Primary cultures derived from retinoblastoma tumors can be established as non-adherent tumorspheres when grown in defined media or as attached monolayers when grown in serum-containing media. While the RB1 genotypes of tumorspheres match those of the primary tumor, adherent cultures have the germline RB1 genotype. Tumorspheres derived from pRb-negative tumors do not express pRb and express the neuroendocrine tumor markers synaptophysin and microtubule-associated protein 2 (MAP2). Adherent cells are synaptophysin-negative and express pRb, the epithelial cell marker cytokeratin that is expressed in the retinal pigmented epithelium and the vascular endothelial cell marker CD34. While tumorspheres are of malignant origin, our results cast doubt on the assumption that adherent tumor-derived cultures are always valid in vitro models of malignant cells and emphasize the need for validation of primary tumor cultures.
...
PMID:Tumorspheres but not adherent cells derived from retinoblastoma tumors are of malignant origin. 2382 78

Oncogenic receptor tyrosine kinase (RTK) signaling through the Ras-Raf-Mek-Erk (Ras-MAPK) pathway is implicated in a wide array of carcinomas, including those of the breast. The cyclin-dependent kinases (CDKs) are implicated in regulating proliferative and survival signaling downstream of this pathway. Here, we show that CDK inhibitors exhibit an order of magnitude greater cytotoxic potency than a suite of inhibitors targeting RTK and Ras-MAPK signaling in cell lines representative of clinically recognized breast cancer (BC) subtypes. Drug combination studies show that the pan-CDK inhibitor, flavopiridol (FPD), synergistically potentiated cytotoxicity induced by the Raf inhibitor, sorafenib (SFN). This synergy was most pronounced at sub-EC50 SFN concentrations in MDA-MB-231 (KRAS-G13D and BRAF-G464V mutations), MDA-MB-468 [epidermal growth factor receptor (EGFR) overexpression], and SKBR3 [ErbB2/EGFR2 (HER-2) overexpression] cells but not in hormone-dependent MCF-7 and T47D cells. Potentiation of SFN cytotoxicity by FPD correlated with enhanced apoptosis, suppression of retinoblastoma (Rb) signaling, and reduced Mcl-1 expression. SFN and FPD were also tested in an MDA-MB-231 mammary fat pad engraftment model of tumorigenesis. Mice treated with both drugs exhibited reduced primary tumor growth rates and metastatic tumor load in the lungs compared to treatment with either drug alone, and this correlated with greater reductions in Rb signaling and Mcl-1 expression in resected tumors. These findings support the development of CDK and Raf co-targeting strategies in EGFR/HER-2-overexpressing or RAS/RAF mutant BCs.
 ...
PMID:Flavopiridol synergizes with sorafenib to induce cytotoxicity and potentiate antitumorigenic activity in EGFR/HER-2 and mutant RAS/RAF breast cancer model systems. 2390 94


<< Previous 1 2 3 4 5 6 7 Next >>