The apoptotic effects of the flavonoid N101-2 in human cervical cancer cells.
ABSTRACT This study evaluated the anti-cancer effects of a naringenin derivative in human cervical cancer cells. In this study, a synthesized naringenin derivative, diethyl 5,7,4'-trihydroxy flavanone N-phenyl hydrazone (N101-2), inhibited cervical cancer cell growth, whereas naringenin itself exhibited no anti-cancer activity. N101-2 treatment inhibited cancer cell viability in a dose- and time-dependent manner through cell cycle arrest at sub-G1 phase, accompanied by an increase in apoptotic cell death. Expression of cyclins and ppRB was down-regulated, whereas that of CDK inhibitors and p53 increased upon N101-2 treatment. Meanwhile, we detected processing of caspases-8, -9, and -3, cleavage of PARP, as well as Bax up-regulation, which indicates activation of mitochondria-emanated intrinsic apoptosis signaling. Treatment with caspase-8 and -3 inhibitors also recovered cell cycling, and Fas/FasL expression increased in N101-2-treated cervical cancer cells, suggesting that Fas-mediated extrinsic apoptosis signaling was also activated. The tumor suppressor PTEN and its upstream regulator PPARγ were up-regulated with coincident inhibition of PI3K and phospho-Akt after N101-2 treatment. Taken together, we could conclude that N101-2 induces apoptosis by arresting the cell cycle at sub-G1 phase, activating mitochondria-emanated intrinsic and Fas-mediated extrinsic signaling pathways, and inhibiting the PI3K/AKT pathway in CaSki and SiHa human cervical cancer cells.
- SourceAvailable from: Vincent Peter Collins[show abstract] [hide abstract]
ABSTRACT: The PTEN (MMAC1) gene, which has been identified as a tumor suppressor gene at 10q23.3, is mutated in multiple malignant tumors, including glioblastomas [J. Li et al., Science (Washington DC), 275: 1943-1947, 1997; P. A. Steck et al., Nat. Genet., 15: 356-362, 1997]. Among tumors of the central nervous system, loss of 10q is not restricted to glioblastomas but is also common in atypical and anaplastic meningiomas. Therefore, we have investigated 36 glioblastomas and 34 meningiomas (2 benign, 17 atypical, and 15 anaplastic meningiomas) for loss on 10q, as well as deletion, mutation, and expression of PTEN. Analysis of eight microsatellites from 10q revealed loss of heterozygosity (LOH) in 25 of 36 glioblastomas (69%). Twenty-three of these tumors demonstrated LOH at all informative loci. Two glioblastomas showed LOH restricted to markers located distally to PTEN, with breakpoints mapping telomeric to D10S541 and D10S185. One glioblastoma demonstrated evidence of homozygous deletion of PTEN by differential PCR analysis. PTEN mutations were detected in 9 of 36 glioblastomas (25%). Seven of these tumors showed LOH at all informative loci from 10q, indicating complete loss of wild-type PTEN. Although loss of 10q was detected by comparative genomic hybridization and/or LOH analysis in 14 of the 34 meningiomas investigated (41%), none of these tumors showed evidence of PTEN mutations or homozygous gene deletions. Our findings corroborate that PTEN is inactivated in a subset of glioblastomas. However, the lack of detectable PTEN alterations in a considerable fraction of glioblastomas and all meningiomas with 10q loss strongly supports the hypothesis that at least one additional tumor suppressor gene is located on 10q.Cancer Research 02/1998; 58(1):29-33. · 8.65 Impact Factor