BACKGROUND
Cancers arise from multiple acquired mutations, which presumably occur over many years. Early stages in cancer development might be present years before cancers become clinically apparent.
METHODS
We analyzed data from whole-exome sequencing of DNA in peripheral-blood cells from 12,380 persons, unselected for cancer or hematologic phenotypes. We identified somatic mutations on the basis of unusual allelic fractions. We used data from Swedish national patient registers to follow health outcomes for 2 to 7 years after DNA sampling.
RESULTS
Clonal hematopoiesis with somatic mutations was observed in 10% of persons older than 65 years of age but in only 1% of those younger than 50 years of age. Detectable clonal expansions most frequently involved somatic mutations in three genes (DNMT3A, ASXL1, and TET2) that have previously been implicated in hematologic cancers. Clonal hematopoiesis was a strong risk factor for subsequent hematologic cancer (hazard ratio, 12.9; 95% confidence interval, 5.8 to 28.7). Approximately 42% of hematologic cancers in this cohort arose in persons who had clonality at the time of DNA sampling, more than 6 months before a first diagnosis of cancer. Analysis of bone marrow–biopsy specimens obtained from two patients at the time of diagnosis of acute myeloid leukemia revealed that their cancers arose from the earlier clones.
CONCLUSIONS
Clonal hematopoiesis with somatic mutations is readily detected by means of DNA sequencing, is increasingly common as people age, and is associated with increased risks of hematologic cancer and death. A subset of the genes that are mutated in patients with myeloid cancers is frequently mutated in apparently healthy persons; these mutations may represent characteristic early events in the development of hematologic cancers. (Funded by the National Human Genome Research Institute and others.)
We conclude that APR-246 is safe at predicted therapeutic plasma levels, shows a favorable pharmacokinetic profile, and can induce p53-dependent biologic effects in tumor cells in vivo.
Capsaicin is the major pungent ingredient in red peppers. Here, we report that it has a profound antiproliferative effect on prostate cancer cells, inducing the apoptosis of both androgen receptor (AR)-positive (LNCaP) and -negative (PC-3, DU-145) prostate cancer cell lines associated with an increase of p53, p21, and Bax. Capsaicin down-regulated the expression of not only prostate-specific antigen (PSA) but also AR. Promoter assays showed that capsaicin inhibited the ability of dihydrotestosterone to activate the PSA promoter/enhancer even in the presence of exogenous AR in LNCaP cells, suggesting that capsaicin inhibited the transcription of PSA not only via downregulation of expression of AR, but also by a direct inhibitory effect on PSA transcription. Capsaicin inhibited NF-K activation by preventing its nuclear migration. In further studies, capsaicin inhibited tumor necrosis factor-A-stimulated degradation of IKBA in PC-3 cells, which was associated with the inhibition of proteasome activity. Taken together, capsaicin inhibits proteasome activity which suppressed the degradation of IKBA, preventing the activation of NF-KB. Capsaicin, when given orally, significantly slowed the growth of PC-3 prostate cancer xenografts as measured by size [75 F 35 versus 336 F 123 mm 3 (FSD); P = 0.017] and weight [203 F 41 versus 373 F 52 mg (FSD); P = 0.0006; capsaicin-treated versus vehicletreated mice, respectively]. In summary, our data suggests that capsaicin, or a related analogue, may have a role in the management of prostate cancer. (Cancer Res 2006; 66(6): 3222-9)
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