PubMed · 11375967
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S J Spechler. 2001. Disputing dysplasia.. https://doi.org/10.1053/gast.2001.25291
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The transcription factor NF-kappaB/Rel was found to be constitutively activated in human pancreatic cancer. RelA is present in the nucleus in primary human pancreatic cancer samples as well as in pancreatic cancer cell lines. NF-kappaB/Rel-binding activity consists of NF-kappaB1(p50) and RelA(p65). Constitutive NF-kappaB/Rel activity correlates with IkappaB kinase (IKK) activity and can be blocked by dominant negative mutants of IKKbeta and to a lesser extent by IKKalpha. Constitutive NF-kappaB/Rel activity and the transactivation potential of RelA(p65) can be inhibited by dominant negative mutant Ras, the PI3 kinase inhibitor LY294002, or dominant negative mutant Akt kinase. Transfection of a dominant negative mutant epidermal growth factor receptor (EGF-R), EGF-R kinase inhibitor Tyrphostin and LY 294002 blocked IKK activity and NF-kappaB-dependent transcription. Inhibition of constitutive IKK or NF-kappaB/Rel activity increased the number of apoptotic cells. Stably expressing a nondegradable form of IkappaBalpha inhibited anchorage-dependent and -independent proliferation in MiaPaCa2 and Panc1 cells. Our data demonstrate that an EGF-R/Ras/PI3 kinase/Akt/IKK-dependent pathway contributes to constitutive NF-kappaB/Rel activity in pancreatic cancer. Inhibition of NF-kappaB/Rel activity reveals a mitogenic and antiapoptotic role for NF-kappaB/Rel in pancreatic cancer.
The Ki-67 protein is tightly regulated and depends on the proliferative status of a cell. It is present in the nuclei of proliferating cells but absent in resting cells. Since transformation of malignant cells is frequently associated with high cell proliferation and since proliferation is tightly associated with the Ki-67 protein labeling index, this antigen may represent a potential target for cancer therapy. In the present study we determined the ability of a phosphorothioate antisense oligodeoxyribonucleotide (ODN) targeted against Ki-67 mRNA to inhibit tumor cell proliferation specifically in cell culture, in multicellular 3-dimensional spheroids (MCS) and in subcutaneous murine tumor models. Antisense treatment of 1 myeloid and different epithelial tumor cell lines in suspension and monolayer culture, respectively, resulted in specific reduction of Ki-67 mRNA and protein, inhibition of proliferation and increased apoptotic cell death. Multicellular human bladder carcinoma spheroids lost their 3-dimensional structure and underwent cell death after incubation with antisense oligonucleotides. The growth of subcutaneous syngeneic prostatic (p = 0.05) and transitional cell tumors (p = 0.001) in immunocompetent mice was significantly inhibited in antisense-treated animals. From these findings we conclude that antisense inhibition of Ki-67 protein expression may be a rational approach in anticancer therapy.
Previous studies have suggested strong evidence for a hereditary component to prostate cancer (PC) susceptibility. Here, we analyze 3,796 individuals in 263 PC families recruited as part of the ongoing Prostate Cancer Genetic Research Study (PROGRESS). We use Markov chain Monte Carlo (MCMC) oligogenic segregation analysis to estimate the number of quantitative trait loci (QTLs) and their contribution to the variance in age at onset of hereditary PC (HPC). We estimate 2 covariate effects: diagnosis of PC before and after prostate-specific antigen (PSA) test availability, and presence/absence of at least 1 blood relative with primary neuroepithelial brain cancer (BC). We find evidence that 2 to 3 QTLs contribute to the variance in age at onset of HPC. The 2 QTLs with the largest contribution to the total variance are both effectively dominant loci. We find that the covariate for diagnosis before and after PSA test availability is important. Our findings for the number of QTLs contributing to HPC and the variance contribution of these QTLs will be instructive in mapping and identifying these genes.