Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The majority of hematopoietic malignancies have aberrancies in the retinoblastoma (Rb) pathway. Loss in Rb function is, in most cases, a result of the phosphorylation and inactivation of Rb by the cyclin-dependent kinases (cdks), main regulators of cell cycle progression. Flavopiridol, the first cdk modulator tested in clinical trials, is a flavonoid that inhibits several cdks with evidence of cell cycle block. Other interesting preclinical features are the induction of apoptosis, promotion of differentiation, inhibition of angiogenic processes and modulation of transcriptional events. Initial clinical trials with infusional flavopiridol demonstrated activity in some patients with non-Hodgkin's lymphoma, renal, prostate, colon and gastric carcinomas. Main side-effects were secretory diarrhea and a pro-inflammatory syndrome associated with hypotension. Phase 2 trials with infusional flavopiridol in CLL and mantle cell lymphoma, other schedules and combination with standard chemotherapies are ongoing. The second cdk modulator tested in clinical trials, UCN-01, is a potent protein kinase C inhibitor that inhibits cdk activity in vitro as well. UCN-01 blocks cell cycle progression and promotes apoptosis in hematopoietic models. Moreover, UCN-01 is able to abrogate checkpoints induced by genotoxic stress due to modulation in chk1 kinase. The first clinical trial of UCN-01 demonstrated very prolonged half-life (approximately 600 h), 100 times longer than the half-life observed in preclinical models. This effect is due to high binding affinity of UCN-01 to the human plasma protein alpha-1-acid glycoprotein. Main side-effects in this trial were headaches, nausea/vomiting, hypoxemia and hyperglycemia. Clinical activity was observed in patients with melanoma, non-Hodgkin's lymphoma and leiomyosarcoma. Of interest, a patient with anaplastic large cell lymphoma refractory to high-dose chemotherapy showed no evidence of disease after 3 years of UCN-01 therapy. Trials of infusional UCN-01 in combination with Ara-C or gemcitabine in patients with acute leukemia and CLL, respectively, have commenced. In conclusion, flavopiridol and UCN-01 are cdk modulators that reach biologically active concentrations effective in modulating CDK in vitro, and show encouraging results in early clinical trials in patients with refractory hematopoietic malignancies. Although important questions remain to be answered, these positive experiences will hopefully increase the therapeutic modalities in hematological malignancies.
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PMID:Development of cyclin-dependent kinase modulators as novel therapeutic approaches for hematological malignancies. 1124 75

The majority of human malignancies have aberrancies in the Retinoblastoma (Rb) pathway. Loss in Rb function results from the phosphorylation and inactivation of Rb by the cyclin-dependent kinases (cdks), main regulators of cell cycle progression. Thus, modulators of cdks may have a role in the treatment of human malignancies. Flavopiridol, the first cdk modulator tested in clinical trials, demonstrates interesting preclinical features: cell cycle block, induction of apoptosis, promotion of differentiation, inhibition of angiogenic processes and modulation of transcriptional events. Initial clinical trials with infusional flavopiridol demonstrated activity in some patients with lymphomas and renal, colon gastric carcinomas. Main side effects were diarrhea and hypotension. Phase 2 trials with infusional flavopiridol, other schedules and combination with standard chemotherapies are ongoing. The second cdk modulator tested in clinical trials, UCN-01, is a PKC inhibitor that can also modulate cdk activity. Similar to flavopiridol, UCN-01 blocks cell cycle progression and promotes apoptosis. Moreover, UCN-01 may abrogate checkpoints induced by genotoxic stress due to inhibition of chk1 kinase. The first clinical trial of UCN-01 demonstrated very prolonged half-life (approximately 600 h), due to high binding affinity of UCN-01 to the human alpha-1-acid glycoprotein. Main side effects were headaches, vomiting, hypoxemia and hyperglycemia. Clinical activity was observed in some patients with melanoma and lymphoma. Trials of shorter infusions of UCN-01 or in combination with standard chemotherapeutic agents are ongoing. Although several important basic and clinical questions remain unanswered, development of cdk modulators is a reasonable strategy for cancer therapy.
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PMID:Small molecule modulators of cyclin-dependent kinases for cancer therapy. 1142 45