Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Overexpression of Bcl-2 protein in cancer cells can inhibit programmed cell death and engender chemoresistance. Reducing Bcl-2 protein levels by using antisense oligonucleotides targeting the gene message can increase the sensitivity of cancer cells to cytotoxic agents. The objective of this work was to investigate the antitumor efficacy of the Bcl-2 antisense oligonucleotide oblimersen (Genasense; G3139), alone and in combination with vinorelbine (VNB), in an ectopic and orthotopic xenograft model of NCI-H460 human non-small-cell lung cancer. In addition to assessing therapeutic effect, Bcl-2 protein expression in tumor tissue isolated from lung and heart was measured. In the ectopic xenograft model, oblimersen at 5 and 10 mg/kg significantly inhibited tumor growth compared with saline-treated control groups, and furthermore, the antitumor effect of oblimersen was associated with down-regulation of Bcl-2 protein in isolated tumor tissue. Moreover, the combination of oblimersen with VNB was more active in inhibiting tumor growth than either drug used alone. In the orthotopic model, oblimersen treatment (5 mg/kg) increased the median survival time of mice to 33 days in comparison with a median survival time of 21 days in the control animals. With this model, the anticancer effect was demonstrated by assessing tumor growth in lung and heart tissues by hematoxylin and eosin staining and Bcl-2 expression by immunohistochemistry. When VNB at 5 mg/kg was combined with oblimersen administered at 5 mg/kg, 33% of mice survived more than 90 days. These data suggest that the combination of oblimersen and VNB may provide enhanced antitumor activities against non-small-cell lung cancer.
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PMID:Antitumor efficacy of oblimersen Bcl-2 antisense oligonucleotide alone and in combination with vinorelbine in xenograft models of human non-small cell lung cancer. 1556 99

Nasopharyngeal carcinoma (NPC) is causally linked to Epstein-Barr virus (EBV), and the EBV oncoprotein, latent membrane protein 1 (LMP-1), is expressed in the majority of NPCs. LMP-1 upregulates antiapoptotic genes, including bcl-2, and Bcl-2 protein is overexpressed in NPC. Given the antiapoptotic and chemoprotective effects of Bcl-2, it represents a rational therapeutic target in NPC. We have investigated the antitumor and chemosensitizing effects of the Bcl-2 antisense oligodeoxynucleotide G3139 (oblimersen, Genasense) in NPC. For these studies, we used the C666-1 line, a stably infected NPC-derived line that co-expresses LMP-1 and Bcl-2. We have shown that G3139 treatment of C666-1 in vitro caused sequence-dependent suppression of Bcl-2 protein, inhibition of cell growth and enhanced sensitivity to cisplatin (CDDP), as measured by increased antiproliferative and apoptotic effects. In vivo, G3139 treatment (25 mg/kg every 3 days x 5 doses) delayed engraftment and significantly inhibited growth of established C666-1 xenografts in SCID mice compared to control oligo-treated animals. However, G3139 alone did not prevent engraftment or cure established tumors in any animals. In contrast, G3139 treatment (25 mg/kg every 3 days x 5 starting on day 7) in combination with CDDP (8 mg/kg on day 14) completely abrogated tumor engraftment in 80% of animals compared to CDDP (0%) or CDDP + control oligo (0%). When treatment was delayed until tumor was established, G3139 in combination with CDDP significantly inhibited tumor growth compared to CDDP or CDDP + control oligo, and cured 69% animals with established tumors. No animals treated with G3139, CDDP or CDDP + control oligo were cured. Tumor burden and response to treatment correlated with EBV DNA load in serum, measured by real-time PCR. Western blots of tumor extracts obtained during oligo treatment showed that Bcl-2 levels were significantly decreased in G3139-treated animals. Our studies have demonstrated that the Bcl-2 antisense oligodeoxynucleotide, G3139, has proapoptotic effects in C666-1, and in combination with CDDP, is curative in C666-1 NPC xenograft tumors in vivo. The sequence-dependency of these effects is consistent with an antisense mechanism. These studies suggest that Bcl-2 may represent a biologically relevant target for the development of novel combinatorial therapies for NPC.
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PMID:Systemic Bcl-2 antisense oligodeoxynucleotide in combination with cisplatin cures EBV+ nasopharyngeal carcinoma xenografts in SCID mice. 1647 27

G3139 (Genasense), an 18mer phosphorothioate antisense oligonucleotide targeted to the initiation codon region of the Bcl-2 messenger RNA (mRNA), downregulates Bcl-2 protein and mRNA expression in many cell lines. However, both the in vitro and in vivo mechanisms of action of G3139 are still uncertain. The isosequential L-deoxyribose enantiomer L-G3139, which does not downregulate Bcl-2 expression, was synthesized to study the role of the Bcl-2 protein in melanoma cells. Both D-G3139 and L-G3139 bind nonspecifically to basic fibroblast growth factor with approximately the same K(c), and cause highly effective inhibition of net formation in 518A2 melanoma cells on Matrigel. The uptakes of D-G3139 and L-G3139 in melanoma cells were also similar. However, unlike D-G3139, L-G3139 does not produce poly ADP-ribose polymerase-1 and procaspase-3 cleavage at 9.5 h after the initiation of the transfection, but can activate the intrinsic pathway of apoptosis at approximately 48 h. Furthermore, treatment of A375 melanoma human xenografts in severe combined immunodeficiency (SCID) mice demonstrates that tumor growth is not inhibited by L-G3139, whereas D-G3139 significantly inhibits the rate of tumor growth. Furthermore, the immunostimulatory properties of L-G3139 appear to be nil, which differs dramatically from those of D-G3139. In conclusion, profound differences exist between D-G3139 and L-G3139 in vivo despite their similarities in vitro.
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PMID:Comparison of d-g3139 and its enantiomer L-g3139 in melanoma cells demonstrates minimal in vitro but dramatic in vivo chiral dependency. 1723 4