Rita Chakrabarti

Curcumin Suppresses Growth of Head and Neck Squamous Cell Carcinoma

Purpose: The purpose of this study was to determine whether curcumin would trigger cell death in the head and neck squamous cell carcinoma (HNSCC) cell lines CCL 23, CAL 27, and UM-SCC1 in a dose-dependent fashion. Experimental Design: HNSCC cells were treated with curcumin and assayed for in vitro growth suppression using 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyl tetrazolium bromide and fluorescence-activated cell sorting analyses. Expression of p16, cyclin D1, phospho-Iκβ, and nuclear factor-κβ (NF-κβ) were measured by Western blotting, gel shift, and immunofluorescence. Results: Addition of curcumin resulted in a dose-dependent growth inhibition of all three cell lines. Curcumin treatment resulted in reduced nuclear expression of NF-κβ. This effect on NF-κβ was further reflected in the decreased expression of phospho-Iκβ-α. Whereas the expression of cyclin D1, an NF-κβ–activated protein, was also reduced, there was no difference in the expression of p16 at the initial times after curcumin treatment. In vivo growth studies were done using nude mice xenograft tumors. Curcumin was applied as a noninvasive topical paste to the tumors and inhibition of tumor growth was observed in xenografts from the CAL27 cell line. Conclusions: Curcumin treatment resulted in suppression of HNSCC growth both in vitro and in vivo. Our data support further investigation into the potential use for curcumin as an adjuvant or chemopreventive agent in head and neck cancer.

Deletion mapping of endocrine tumors localizes a second tumor suppressor gene on chromosome band 11q13

Multiple endocrine neoplasia type 1 syndrome (MEN1, MIM 131100), an autosomal dominant disease, is characterized by parathyroid hyperplasia, pancreatic endocrine tumors, and pituitary adenomas. These tumors also occur sporadically. Both the familial (MEN1) and the sporadic tumors reveal loss of heterozygosity (LOH) for chromosome band 11q13 sequences. Based on prior linkage and LOH analyses, the MEN1 gene was localized between PYGM and D11S460. Recently, the MEN1 gene (menin) has been cloned from sequences 30‐kb distal to PYGM. We performed deletion mapping on 25 endocrine tumors (5 MEN1 and 20 sporadic) by using 21 polymorphic markers on chromosome band 11q13. Of these, two (137C7A, 137C7B) were derived from PYGM‐containing BAC (bacterial artificial chromosome‐137C7) sequences, one from INT2‐containing cosmid sequences and the marker D11S4748, a (CA)20 repeat marker that was developed by us. The LOH analysis shows that the markers close to the MEN1 (menin) gene were not deleted in three of the tumors. These tumors, however, showed LOH for distal markers. Thus, the data suggest the existence of a second tumor suppressor gene on chromosome band 11q13. Genes Chromosomes Cancer 22:130–137, 1998.

Mapping of nasopharyngeal carcinoma tumor-suppressive activity to a 1.8-megabase region of chromosome band 11q13.

Nasopharyngeal carcinoma (NPC) is a malignancy that is particularly prevalent among populations from Southern China and Southeast Asian countries. Evidence for a genetic contribution to the disease has been documented, although the genetic basis for NPC development is not yet fully understood. Previous functional evidence of tumor‐suppressive activity on chromosome band 11q13 in NPC was obtained using a microcell‐mediated chromosome‐transfer approach with HONE1 NPC cells. In the present study, this region was subjected to a detailed investigation of microcell hybrids and their tumor segregants using microsatellite analysis to narrow down the region of tumor‐suppressive activity. Fluorescence in situ hybridization was also performed with BAC and cosmid probes to confirm the microsatellite data. The critical region responsible for tumor suppression was narrowed down to a 1.8‐Mb interval, which does not tolerate an additional normal allele by chromosome transfer. One or two alleles from either endogenous or exogenous chromosomes at 11q13 were consistently eliminated during tumor growth. Results of this study suggest that a candidate tumor‐suppressor gene, not the MEN1 gene, maps between D11S4907 and GSTP1 in NPC.

Homozygous deletions within the 11q13 cervical cancer tumor-suppressor locus in radiation-induced, neoplastically transformed human hybrid cells.

Studies on nontumorigenic and tumorigenic human cell hybrids derived from the fusion of HeLa (a cervical cancer cell line) with GM00077 (a normal skin fibroblast cell line) have demonstrated “functional” tumor‐suppressor activity on chromosome 11. It has been shown that several of the neoplastically transformed radiation‐induced hybrid cells called GIMs (gamma ray induced mutants), isolated from the nontumorigenic CGL1 cells, have lost one copy of the fibroblast chromosome 11. We hypothesized, therefore, that the remaining copy of the gene might be mutated in the cytogenetically intact copy of fibroblast chromosome 11. Because a cervical cancer tumor suppressor locus has been localized to chromosome band 11q13, we performed deletion‐mapping analysis of eight different GIMs using a total of 32 different polymorphic and microsatellite markers on the long arm (q arm) of chromosome 11. Four irradiated, nontumorigenic hybrid cell lines, called CONs, were also analyzed. Allelic deletion was ascertained by the loss of a fibroblast allele in the hybrid cell lines. The analysis confirmed the loss of a fibroblast chromosome 11 in five of the GIMs. Further, homozygous deletion (complete loss) of chromosome band 11q13 band sequences, including that of D11S913, was observed in two of the GIMs. Detailed mapping with genomic sequences localized the homozygous deletion to a 5.7‐kb interval between EST AW167735 and EST F05086. Southern blot hybridization using genomic DNA probes from the D11S913 locus confirmed the existence of homozygous deletion in the two GIM cell lines. Additionally, PCR analysis showed a reduction in signal intensity for a marker mapped 31 kb centromeric of D11S913 in four other GIMs. Finally, Northern blot hybridization with the genomic probes revealed the presence of a novel >15‐kb transcript in six of the GIMs. These transcripts were not observed in the nontumorigenic hybrid cell lines. Because the chromosome 11q13 band deletions in the tumorigenic hybrid cell lines overlapped with the minimal deletion in cervical cancer, the data suggest that the same gene may be involved in the development of cervical cancer and in radiation‐induced carcinogenesis. We propose that a gene localized in proximity to the homozygous deletion is the candidate tumor‐suppressor gene.

Curcumin suppresses growth of head and neck squamous cell carcinoma

Problem: To determine whether curcumin would trigger cell death in head and neck squamous cell carcinoma (HNSCC) cell lines CCL 23, CAL 27, UMSCC-1, and UMSCC-14 in a dose-dependent fashion. Methods: In-vitro studies included MTT assay and Annexin V-FITC flow cytometry of the HNSCC cells at 8 and 15 hours after treatment with curcumin. In vivo studies were done on HNSCC xenograft tumors grown in nude mice, using curcumin paste applied topically to the tumors daily for 4 weeks. Results: CCL23 cell lines had dose-dependent reduction in cell viability following treatment with curcumin, with nearly 100% cell survival at 100 μM and less than 5% survival at 300 μM. CAL27 cell lines showed reduction of cell viability beginning at 60 μM, and 0% survival at 300 μM. UMSCC-1 cell lines showed reduction in cell viability from 70% at 100 μM to 0% at 200 μM, at both 8 and 15 hours after treatment. UMSCC-14A cell lines showed similar sensitivity, with an average 40% reduction in viability beginning at 100 μM and 0% survival at 200 μM. Flow cytometry demonstrated early and late apoptosis with the curcumin-treated CCL23 and CAL27 cells. The xenograft tumors exhibited more than 50% decrease in size with the curcumin/saline paste. Conclusion: Curcumin has a direct effect on CCL23, CAL27, UMSCC-1, and UMSCC-14, reducing viability in both cell lines in a dose-dependent fashion. In addition, curcumin/saline paste had a significant suppressive effect on HNSCC xenograft tumors, confirming curcumin’s anti-tumor properties in vivo. Significance: To determine whether curcumin would trigger cell death in head and neck squamous cell carcinoma cell lines. Support: None reported.