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)

Messenger RNA levels of the c-fos, c-myc, c-Ha-ras and c-Ki-ras genes were studied in 39 tissue samples obtained from 17 patients undergoing surgery for colon carcinoma and other colon diseases. DNA extracted from the same samples was studied by Southern analysis. The tissues were tumors and grossly normal mucosa from each case and in some instances benign polyps and metastases. Our results indicate: (1) that 50% of cases studied show an increase in expression of at least one of the oncogenes studied; (2) that over-expression is not random, some cases over-expressing several of the genes studied; (3) that the expression pattern of the oncogenes studied varies between primary tumor and metastases; (4) that amplification is a rare event, being limited to one instance in which c-myc was amplified in a metastasis; (5) that cases which exhibit high levels of mRNA in one or more genes studied correlate with biologically aggressive tumors; and (6) that "non-expressors" are at higher risk for local recurrence based on correlations with mucin histochemistry.
 ...
PMID:Prognostic implications of expression of the cellular genes myc, fos, Ha-ras and Ki-ras in colon carcinoma. 304 May 97

A modification of the polymerase chain reaction technique (PCR) technique, a primer-mediated enzymatic amplification of specific target sequences in genomic DNA, was used to introduce point mutations into copies of human ras oncogene sequences, and to amplify these mutated copies approximately 10(6)-fold. Of the two flanking oligomers used to amplify the DNA, one contained a single base mismatch with the targeted gene segment, either codon 12 or 61 from the Kirsten ras oncogene. Double-stranded fragments harboring any point mutation can be generated using the appropriate oligomer and constitute greater than 99.999% of the PCR-amplified fragments. The amplified DNA fragments are readily slot-blotted to nylon membranes to serve as positive hybridization controls in the search for gene mutations in human tissue specimens. The synthesis of single base mismatched DNA fragments was also used to demonstrate that oncogene mutations can be detected from mixed DNA populations as might be present in primary tumor specimens, even when the mutation of interest is present in only 5% of the amplified sample DNA.
 ...
PMID:Use of the polymerase chain reaction technique to create base-specific ras oncogene mutations. 306 61

The differential expression of the ras oncogene product p21 in the primary tumor, regional nodes, and distant metastatic sites in patients with disseminated breast cancer was examined to define the biologic and clinical significance of the ras oncogene in the progression of breast cancer. The avidin-biotin peroxidase complex method was used on formalin-fixed, paraffin-embedded tissues from 16 patients with metastatic disease. The primary antibody used in this protocol was RAP-5, an anti-p21 murine monoclonal IgG2a. p21 antigen staining was similar in the primary tumor and regional nodes from the same patient (P less than 0.05), but the staining of distant metastases was more variable. Expression of ras p21 was consistently increased in invasive components of the primary tumor as compared with intraductal tumor. In addition, a high level of p21 expression was seen in tumor emboli in lymphatics and blood vessels as compared with contiguous tumor in parenchymal tissue. Although p21 staining is present in aggressive primary breast cancers and most metastatic sites, our findings indicate that markedly enhanced p21 expression is associated with the earlier stages (invasion and dissemination) of aggressive breast cancers.
 ...
PMID:ras p21 expression in the progression of breast cancer. 331 56

High-molecular-weight genomic DNA isolated from a human cutaneous squamous cell carcinoma (AS) was assayed for its ability to induce tumorigenic transformation of NIH 3T3 cells. Subcutaneous injection of NIH 3T3 cells cotransfected with DNAs from AS tumor and pSV2-neo plasmid not only induced tumors at the site of injection, but also metastasized spontaneously to the lungs in 100% of nude mice injected. DNA isolated from a representative primary tumor and a metastasis was again used in a second round of transfection. Injection of secondary transfectants into nude mice again resulted in induction of both subcutaneous tumors and spontaneous long metastases. Southern blot hybridization with ras-specific probes revealed that DNA from both primary tumors and metastases induced by AS tumor DNA contained highly amplified Ha-ras oncogene. Furthermore, DNAs from secondary tumors and metastases induced by DNA from a primary tumor and a metastasis also contained similar highly amplified Ha-ras oncogene. These results suggest that the amplified Ha-ras oncogene may be responsible for induction of both tumorigenic and metastatic phenotypes in NIH 3T3 cells transfected with DNA from AS tumor.
 ...
PMID:Simultaneous transfer of tumorigenic and metastatic phenotypes by transfection with genomic DNA from a human cutaneous squamous cell carcinoma. 335 53

The protein product of the ras cellular oncogene(s) (p21) was assayed in primary breast carcinomas from two groups of patients who had different axillary lymph node status. Using an immunohistochemical assay, the intensity and percent of neoplastic cells demonstrating ras p21 antigen staining were significantly higher in the primary tumors from patients with lymph nodes positive (LN+) for malignancy (20 patients) compared with the lymph node negative (LNO) group (21 patients). The expression of p21 also correlated with tumor size. Age and estrogen receptor status did not influence p21 staining. The antigen expression of p21 was similar in intensity and distribution in the primary tumor and regional lymph node metastases. Enhanced expression of p21 in primary breast cancers that metastasize to regional nodes indicates that ras p21 may be a determinant of the malignant potential of breast cancer cells and may represent a new class of more biologically relevant tumor markers.
 ...
PMID:Elevated ras oncogene expression correlates with lymph node metastases in breast cancer patients. 352 1

A human pancreatic cancer cell line, PSN-1, was established from pancreatic adenocarcinoma tissue that had been stored for 1.5 years at -80 degrees C without any special treatment. The stored tissues were first transplanted into nude mice, and from the xenograft, the PSN-1 cell line was established. The original primary tumor and two metastatic lymph nodes were previously found to have 50-fold amplification of c-myc and also 3- to 6-fold amplification of activated c-Ki-ras with a point mutation from GGT to CGT at codon 12. PSN-1 cells are unique in that amplifications of both c-myc and activated c-Ki-ras are present in the same degree as the original tumors. These cells were also found to contain increased amounts of c-myc and c-Ki-ras transcripts.
 ...
PMID:Establishment of a human pancreatic adenocarcinoma cell line (PSN-1) with amplifications of both c-myc and activated c-Ki-ras by a point mutation. 377 42

Cytogenetic studies and analysis of restriction fragment polymorphism (RFLP) have revealed that chromosomes 9, 11 and 17 are frequently altered in urothelial tumors. There are several tumor suppressor genes that might be involved in the oncogenesis of these tumors. The retinoblastoma suppressor gene and p53 have been the subjects of several recent investigations and have been seen to be altered or inactivated in a significant number of tumors. Proto-oncogenes of the ras family have been studied extensively, and c-Ha-ras alterations have been demonstrated in approximately 10% of urothelial tumors. Other proto-oncogenes seem to be involved less frequently. Although correlations between these molecular genetic findings and clinical parameters have been shown by some investigators, further studies are needed to establish whether molecular data are clinically relevant for prognosis, diagnosis and therapy. The sensitivity of molecular genetic techniques combined with the relatively easy access to primary tumor cells (by biopsy or cytology) make this tumor type an ideal system for further investigation of the molecular genetic basis in the development of human neoplasms.
 ...
PMID:[Urothelial cancers. Cytogenetic and molecular biology principles]. 790 68

A new cell line (BRC-230) was established from surgical material of primary ductal infiltrating breast carcinoma. The epithelial nature of this cell line was confirmed by ultrastructural analysis and demonstrated the retention of structural properties characteristic of the original tumor. The BRC-230 cell line induced tumor in athymic Cr1:nu/nu(CD-1)BR nude mice, it possessed an abnormal karyotype with a modal chromosome number between 60-61 with eight recurrent marker chromosomes, and it presented a doubling time of 30.5 hr. Scatchard analysis demonstrated that both primary tumor and BRC-230 cells were estrogen and progesterone receptor negative. Immunoenzymatic and radioimmunoassays showed a production of marker antigens (CEA, TPA, CA125, CA15-3, CA19-9) which was similar in the patient's serum and BRC-230 cells. The in vitro drug sensitivity assay of the cell line and of the parental tumor tissue showed overlapping results to all tested antiblastic drugs. BRC-230 cells were resistant to 4-Idroperoxy-cyclophosphamide, Idarubicinol, Mitoxantrone, Etoposide, 4'Epidoxorubicin, and Doxorubicin, showing a multiple drug resistance phenotype. Amplification or rearrangement of Her-2neu, Ha-ras, and C-myc genes was observed neither in the original tumor nor in BRC-230 cells; the mdr-1 gene was also present in a single copy. We conclude from these studies that the BRC-230 cell line maintains the same characteristics as the original tumor and may provide us with a good model to study in vitro the biology of drug resistance of breast cancer.
 ...
PMID:Establishment and characterization of a new cell line from primary human breast carcinoma. 801 54

The Johns Hopkins Lung Project developed an archive of sputum specimens during a randomized trial of lung cancer screening (1974-1982). We identified 15 patients from that trial who later developed adenocarcinoma of the lung. The primary lung carcinomas from 10 of these 15 patients contained either a ras or a p53 gene mutation. Using a polymerase chain reaction-based assay, stored sputum samples obtained prior to clinical diagnosis were examined for the presence of these same oncogene mutations. In 8 of 10 patients, the identical mutation identified in the primary tumor was also detected in at least one sputum sample. The earliest detection of a clonal population of cancer cells in sputum was in a sample obtained more than 1 year prior to clinical diagnosis. These results provide the basis of a novel approach for detection of lung cancer based on the evolving molecular genetics of this disease.
 ...
PMID:Detection of oncogene mutations in sputum precedes diagnosis of lung cancer. 813 72

In this study we used the subrenal capsule site of C57BL/6J mice to assess the tumorigenic and metastatic potential of established urothelial cell lines in a syngeneic murine model. High tumor take and subsequent removal of the primary tumor by nephrectomy resulted in the extended lifespan of the animals enabling the formation of secondary tumor growth. To test this model we have used a panel of cell lines expressing constitutively, or following transfection, ras oncogene products. All cell lines constitutively expressing ras oncogenes (K, H, or N-ras) were tumorigenic and metastatic in this assay. One non tumorigenic cell line (BBN3) and one tumorigenic but non-metastatic cell line (SH264), remained non-metastatic following transfection with the pSV2-neo gene but formed micrometastases in the lung when a ras oncogene was introduced in the same manner. Expression of altered ras proteins following transfection in these two cell lines was demonstrated using an H-ras specific antibody in Western blot analysis. This study demonstrates the value of the subrenal capsule site as a metastatic assay for bladder cancer and the potential involvement of ras oncogenes in urothelial cell metastasis.
 ...
PMID:[Urothelial cancer metastases after implantation of tumor cells under the kidney capsule]. 837 44


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