Search PubMed⌕ Search

Biomedical subjects

Quan-Yang Duh

Publications and source records attributed to Quan-Yang Duh.

At least 55 records · Page 3Linked to original sources
PubMed2004

GCMB gene, a master regulator of parathyroid gland development, expression, and regulation in hyperparathyroidism.

BACKGROUND: The glial cell missing gene, GCMB , encodes a transcription factor, which is a master regulator of parathyroid development. We postulated that the GCMB gene might play a role in parathyroid tumorigenesis in hyperparathyroidism. METHODS: We used real-time quantitative reverse transcriptase polymerase chain reaction to study GCMB mRNA expression in parathyroid tissue: normal (n = 3), hyperplastic (n = 16), adenomas (n = 19), and cancers (n = 8). In primary parathyroid culture, the effect of CaCl 2 on parathyroid hormone secretion and GCMB mRNA expression was studied by using enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. RESULTS: GCMB mRNA expression was lower in normal (0.4 +/- 0.1, mean +/- standard error of mean) parathyroid glands as compared to adenoma (3.5 +/- 1.7), hyperplasia (3.2 +/- 1.3 primary hyperparathyroidism [n = 11] and 7.6 +/- 4.8 secondary hyperparathyroidism [n = 5]), and cancer (3.6 +/- 1.3) ( P = .001). There was no difference in the level of GCMB mRNA expression between parathyroid adenoma, hyperplasia, and cancer. In primary culture of parathyroid adenoma (n = 9) and hyperplasia (n = 2), parathyroid hormone secretion was increased 2- to 15-fold with low calcium concentration (0.5 to 4.0 mmol/L CaCl 2 from 2 to 6 hours, P < .005). The level of GCMB mRNA expression was down-regulated with lower extracellular CaCl 2 concentration ( P < .005). CONCLUSIONS: GCMB expression is upregulated in abnormal parathyroid glands of hyperparathyroidism and decreases in response to hypocalcemia. The GCMB transcription factor might mediate the effect of calcium on parathyroid cell parathyroid hormone expression/secretion.

Adenoma↗
PubMed2004

Latency period of thyroid neoplasia after radiation exposure.

OBJECTIVE: To determine the temporal sequence for developing benign and malignant thyroid neoplasms after radiation. SUMMARY BACKGROUND DATA: Therapeutic radiation is associated with thyroid neoplasms in humans and animals. Some question whether thyroid cancers develop de novo or from benign thyroid neoplasms. Little information, however, is available concerning the time to development of benign and malignant thyroid neoplasms after radiation exposure. METHODS: We retrospectively analyzed the records of 171 consecutive patients who had a history of exposure to radiation and were treated surgically at University of California, San Francisco-affiliated hospitals for thyroid neoplasms between 1960 and 1999. RESULTS: There were 66 men and 105 women aged 9 to 80 years (mean, 47.0 years). One hundred patients had benign and 71 had malignant tumors (58 papillary cancers, 10 follicular cancers, 1 Hurthle cell cancer, 1 medullary cancer, and 1 carcinosarcoma). The mean latency period for benign tumors was longer than that for malignant lesions (mean, 34.1 and 28.4 years, P = 0.018; median, 38.0 years and 30.0 years, P = 0.001). Follicular carcinomas developed sooner (mean, 20.5 years; median, 20 years) than did follicular adenomas (mean, 35.3 years; median, 36.5 years; P = 0.003, P = 0.0009). Patients with papillary thyroid cancers presenting as occult papillary cancers (<1 cm) and as a dominant nodule had similar latency periods (mean, 34.0 and 28.0 years P = 0.29; median, 37.5 and 30.5 years, P = 0.09), respectively. CONCLUSION: Although there could be selection bias regarding referral of patients, our data document that malignant thyroid tumors after radiation exposure, including follicular carcinomas, present earlier than do benign thyroid tumors. Occult and manifest papillary thyroid cancers present at about the same time interval after radiation exposure. Our findings question whether benign thyroid neoplasms progress to malignant thyroid neoplasms and that most occult thyroid cancers do not progress to malignant thyroid cancers in radiation-exposed patients.

Age Factors↗
PubMed2004

The NIH criteria for parathyroidectomy in asymptomatic primary hyperparathyroidism: are they too limited?

OBJECTIVE: To determine whether preoperative and postoperative symptoms and outcome differ in patients who meet or fail to meet the NIH criteria for parathyroidectomy. SUMMARY BACKGROUND DATA: The NIH Consensus Conference on primary hyperparathyroidism in 1990 defined criteria for surgical intervention suggesting that some patients can be safely managed without surgery. METHODS: Over a 3-year period, 202 consecutive patients undergoing parathyroidectomy for primary hyperparathyroidism at a tertiary referral center were prospectively given a questionnaire regarding their symptoms and associated conditions during their initial and follow-up office visits as were 63 thyroid control patients. The 178 patients who completed the follow-up questionnaire were assigned to 2 groups according to the NIH criteria for parathyroidectomy. The frequency of preoperative symptoms and conditions associated with primary hyperparathyroidism as well as postoperative improvement in symptoms and surgical outcome were compared. RESULTS: Of the 178 parathyroid patients, 103 met the NIH criteria for parathyroidectomy whereas 75 did not. Patient profiles were similar in each group except mean ages, 55 versus 65, and preoperative serum calcium levels, 11.5 mg/dL versus 11.0 mg/dL (NIH and non-NIH groups, respectively; P < 0.001). The incidence of preoperative nonspecific somatic and neuropsychiatric symptoms and associated conditions was equivalent in both groups and more common than in the 63 thyroid control patients. After parathyroidectomy, symptomatic improvement was dramatic and equal between the 2 parathyroid groups. Postoperative mean serum calcium levels were similar (8.78 mg/dL, NIH group, versus 8.75 mg/dL, non-NIH group). CONCLUSION: Symptoms were more common in patients with primary hyperparathyroidism versus thyroid controls, but were not different between those patients who met the NIH criteria for parathyroidectomy and those who did not. Patients in both parathyroid groups benefited symptomatically after successful parathyroidectomy.

Adult↗
PubMed2004

Id1 gene expression is up-regulated in hyperplastic and neoplastic thyroid tissue and regulates growth and differentiation in thyroid cancer cells.

The Id (inhibitor of DNA binding) proteins are a family of helix-loop-helix (HLH) proteins (Id1, Id2, Id3, and Id4) that lack the basic domain necessary for DNA binding. The Id1 protein enhances cell proliferation and inhibits cellular differentiation in a variety of cell types. We have previously demonstrated that the Id1 gene is up-regulated in papillary and medullary thyroid cancers. In this study we characterized the expression and distribution of the Id1 protein in normal, hyperplastic, and neoplastic human thyroid tissue. We also evaluated the effect of the Id1 gene on thyroid cancer cell growth and markers of thyroid cell differentiation. We used semiquantitative immunohistochemistry to characterize Id1 protein expression in normal, hyperplastic (multinodular goiter and Graves' disease), and neoplastic thyroid tissue from 103 patients. Normal thyroid tissue had the lowest level of Id1 protein expression (P < 0.0001). Anaplastic thyroid cancer had the highest level (vs. benign and malignant thyroid tissues, P < 0.01). Id1 protein expression was higher in malignant thyroid tissue than in hyperplastic thyroid tissue (P < 0.02). We found no significant association between the level of Id1 protein expression and patient age, sex, tumor-node-metastasis stage, tumor size, primary tumor vs. lymph node metastasis, primary tumor vs. recurrent tumors, and extent of tumor differentiation. Inhibiting Id1 mRNA expression in thyroid cancer cell lines using Id1 antisense oligonucleotides resulted in growth inhibition (P < 0.03) and decreased thyroglobulin and sodium-iodine symporter mRNA expression (P < 0.02). In conclusion, Id1 is overexpressed in hyperplastic and neoplastic thyroid tissue and directly regulates the growth of thyroid cancer cells of follicular cell origin, but is not a marker of aggressive phenotype in differentiated thyroid cancer.

Adult↗
PubMed2004

Laparoscopic surgery for melanoma metastases to the adrenal gland.

The probability of developing cutaneous melanoma is now predicted to be one in 55 for males and one in 88 for females. Although melanoma is relatively uncommon compared with other malignancies such as breast (one in seven) or prostate cancer (one in six), the incidence is growing at an alarming rate. The development of novel strategies for the management of advanced disease will become even more urgent and require continued and controlled investigations over the next 10 years. Surgery is effective for the palliation of isolated resectable metastases. However, most patients with Stage IV melanoma have widespread disease and are not cured by metastasectomy. For the few individuals with isolated adrenal metastases from melanoma, complete resection appears to confer a survival advantage. New data are emerging about the efficacy and outcome of laparoscopic adrenalectomy for malignant lesions. However, the natural history of laparoscopic surgery for these lesions is still unknown. The indications for and limitations of laparoscopic adrenalectomy for metastatic melanoma are discussed.

Adrenal Gland Neoplasms↗
PubMed2003

Incision length for standard thyroidectomy and parathyroidectomy: when is it minimally invasive?

HYPOTHESIS: Current techniques for open conventional thyroidectomy or parathyroidectomy have evolved to enable a shorter incision (main proposition), and the length of the incision is influenced by objective factors. DESIGN: Case series. SETTING: University referral center. PATIENTS AND INTERVENTION: Retrospective study of the most recent 200 primary consecutive routine thyroid and parathyroid operations (excluding neck dissections). MAIN OUTCOME MEASURES: The length of incision was routinely measured with a ruler before the incision. Univariate and multivariate analysis was performed to distinguish variables affecting length of incision. RESULTS: Mean length of the incision was 5.5 cm for total thyroidectomy, 4.6 cm for lobectomy, and 3.5 cm for parathyroidectomy (P<.001). It was 4.1 cm for bilateral parathyroid exploration, but was reduced to 3.2 and 2.8 cm for unilateral (P<.001) and focal (P<.001) explorations, respectively. By multiple regression analysis, thyroid specimen volume and patient body mass index were independent predictors of incision length in thyroidectomy. Extent of exploration and resident training level were independent predictors of incision length in parathyroidectomy. CONCLUSIONS: Current techniques for open conventional thyroidectomy or parathyroidectomy have evolved to enable a shorter incision. Thyroid volume, patient body mass index, extent of the planned parathyroid exploration, and the resident clinical training stage are important variables for incision length in open operation and should be taken into account when minimally invasive thyroidectomy and parathyroidectomy are evaluated.

Female↗
PubMed2003

Parathyroidectomy for primary hyperparathyroidism in octogenarians and nonagenarians: a plea for early surgical referral.

BACKGROUND: Surgical referral of elderly patients with PHPT is often deferred because of the perceived risks of general anesthesia, increased age, and comorbidities and also because many of the symptoms of PHPT are difficult to distinguish from the aging process. HYPOTHESIS: Parathyroidectomy for primary hyperparathyroidism (PHPT) in elderly patients is beneficial and safe. DESIGN: Retrospective study of patients with PHPT who were 80 years and older. SETTING: Tertiary academic referral medical center. PATIENTS: Fifty-four consecutive patients (43 women and 11 men) with a mean age of 83.6 years who underwent parathyroidectomy for PHPT. MAIN OUTCOME MEASURES: Delay in surgical referral; improvement in symptoms and normalization of serum calcium and parathyroid hormone levels; and perioperative morbidity and mortality. RESULTS: Twelve (22%) of 54 patients had a mean delay of 5 years (range, 1.2-10.0 years) before surgical referral for a known diagnosis of PHPT. No patient had asymptomatic PHPT. There was no significant difference in the preoperative mean serum calcium level and symptoms of PHPT resulting from delay in surgical referral. Parathyroidectomy resulted in significant improvement of PHPT-associated symptoms of fatigue, weight loss, nocturia, bone pain, constipation, and major depression (P<.05). All patients had normal serum calcium and parathyroid hormone levels postoperatively. The average length of hospitalization was 1.9 days. There were 3 complications (9%): 1 urinary tract infection, 1 bladder perforation, and 3 transient hypocalcemia. There was no perioperative mortality. CONCLUSIONS: Parathyroidectomy in elderly patients is safe, curative, and beneficial. Surgical referral for parathyroidectomy should be considered in elderly patients with PHPT.

Aged↗
PubMed2003

Intraoperative parathyroid hormone assay and parathyroid reoperations.

BACKGROUND: The purpose of this study was to determine whether intraoperative parathyroid hormone (IOPTH) assay improved results of reoperations. METHODS: One hundred two patients with persistent/recurrent sporadic primary hyperparathyroidism underwent 108 reoperations (1996-2002). IOPTH was not used (n=58) from 1996-1998 (group 1). IOPTH was used (n=50) from 1999-2002 (group 2). Sensitivity and positive predictive value of IOPTH and its influence on surgical strategy were analyzed. A 50% decrease occurring 10 minutes after removal of parathyroid tumor was used to determine if all abnormal tissue had been removed. RESULTS: Groups 1 (58 patients) and 2 (50 patients) were comparable except for duration of follow-up. The cure rate was 84% (group 1, 87%; group 2, 82%, P=0.7). Hypocalcemia developed in 20 patients (permanent in 2 patients). There was 1 permanent vocal cord paralysis and 1 patient died of toxic shock syndrome. IOPTH successfully predicted cure in 44 of 49 patients (sensitivity, 90%); the positive predictive value was 90%. Values for parathyroid hormone level and the ratio parathyroid hormone/calcium at day 1 were at least as accurate as IOPTH in predicting cure. IOPTH was helpful in 1 patient but misleading in 4 patients. It failed to modify intraoperative strategy in most other patients. CONCLUSIONS: IOPTH testing was relatively reliable in patients with persistent or recurrent sporadic primary hyperparathyroidism, but the test unfortunately failed to improve the overall success rate at reoperation.

Adolescent↗
PubMed2003

Techniques to optimize vascular control during laparoscopic donor nephrectomy.

OBJECTIVES: To review our experience with laparoscopic donor nephrectomy for kidney transplantation and describe our technique of vessel ligation. METHODS: We retrospectively analyzed the method of renal artery and vein control during the 97 laparoscopic donor nephrectomies performed at the University of California, San Francisco, since November 1999. In addition, we examined both donor and recipient outcomes after nephrectomy and transplantation in this cohort. RESULTS: Currently, we ligate the renal artery and renal vein using a single Hem-o-lok polymer clip and a single Endo-TA stapler, respectively, and divide the vessels using scissors without securing the graft-side vessels. In contrast to using the Endo-GIA stapler, there is no need to trim staples (approximately 5 mm) from the vessels before anastomosis. Excellent vessel length was achieved in all cases without donor complications, and 99% of recipients had long-term graft function. The only major complications (blood transfusion, conversion to open surgery) occurred early in the series when we used the Endo-GIA stapler to control the vessels. CONCLUSIONS: Although adequate vessel length is typically obtained during left donor nephrectomy, additional length can be achieved using our modification. This may facilitate right donor nephrectomy and help reduce complications, potentially increasing the recovery of right kidneys for transplantation. In addition, performing vessel ligation and division in separate steps is simple, does not change ischemic time, and appears to increase safety.

Anastomosis, Surgical↗
PubMed2003

Laparoscopic adrenalectomy--indications and technique.

Laparoscopic adrenalectomy has become the procedure of choice for the surgical management of most adrenal tumors, including functional and non-functional lesions. The role of laparoscopic adrenalectomy in the management of malignant adrenal tumors is controversial and most adrenocortical cancers are generally treated by open adrenalectomy. Laparoscopic adrenalectomy can be performed by both the anterior or lateral trans-abdominal approach and by the lateral or posterior retro-peritoneal approach, with each method being suitable for specific indications. Although there are no randomized trials comparing laparoscopic with open adrenalectomy, the laparoscopic approach is associated with shorter hospital stay, reduced pain and improved cosmesis. This review discusses the indications and contraindications, technique and outcomes for laparoscopic adrenalectomy.

Adrenal Gland Neoplasms↗
PubMed2003

Differing histologic findings after bilateral and focused parathyroidectomy.

BACKGROUND: Minimally invasive parathyroid surgery with intraoperative parathyroid hormone testing has been reported to be as successful as a bilateral operation. This study aimed to determine whether the histologic findings and outcomes differ in patients with primary sporadic hyperparathyroidism treated by a focal or a bilateral parathyroid exploration with intraoperative parathyroid hormone testing. To make the two groups comparable all patients had a solitary parathyroid adenoma identified preoperatively. STUDY DESIGN: Eighty unselected patients with primary hyperparathyroidism and a single abnormal parathyroid gland identified preoperatively by sestamibi scanning or ultrasonography were included in this study. All patients had intraoperative parathyroid hormone testing. RESULTS: Forty-five patients had standard bilateral neck explorations and 35 patients had focal neck explorations. In the bilateral neck exploration group a single adenoma was found in 38 patients (84%), a double adenoma in 3 patients (7%), hyperplasia in 3 patients (7%), and carcinoma in 1 patient (2%). In contrast, a single adenoma was identified in all patients in the focal neck exploration group. Sestamibi scanning and intraoperative parathyroid hormone assay were accurate in 87% and 84%, respectively, in the bilateral neck exploration group and in 96.9% and 94.3%, respectively, in the focal neck exploration group. All patients were normocalcemic (mean followup 17 months). CONCLUSIONS: Patients with primary hyperparathyroidism having a bilateral exploration had about a 15% higher rate of multiple parathyroid tumors than did patient having a focal approach. Despite this observation all patients were normocalcemic postoperatively. This suggests that either some histologically abnormal parathyroid glands do not function or there will be recurrences in patients treated by a focused approach. Longterm followup will be necessary to determine whether patients treated by focal neck exploration will develop recurrent primary hyperparathyroidism.

Adenoma↗
PubMed2003

Accuracy of preoperative localization studies and intraoperative parathyroid hormone assay in patients with primary hyperparathyroidism and double adenoma.

BACKGROUND: The purpose of this retrospective investigation was to evaluate the results of preoperative localization studies and intraoperative parathyroid hormone (IOPTH) assay in patients with primary hyperparathyroidism and double adenomas. STUDY DESIGN: Twenty-one of 287 consecutive patients with primary hyperparathyroidism who had double adenomas identified during first-time parathyroid exploration between July 1999 and September 2002 were analyzed. Individual and combined accuracy of preoperative localization studies, and IOPTH assay and their influence on surgical strategy, were compared. RESULTS: Seven percent of these 287 patients had double adenomas. Fifteen of the patients were female and six were male with a mean age of 59 years (range 17 to 76 years). The accuracy of ultrasonography (US) and technetium 99m sestamibi ((99m)TC-sestamibi) was 40% and 30%, respectively, in this select group. Combined accuracy of both tests reached 60% and guided the surgeon to select a bilateral approach. After removal of the first gland, IOPTH failed to decrease by 50% relative to the highest baseline value in 43% of the cases, indicating other hyperfunctioning parathyroid glands. These results prompted the surgeon to explore further after an initially planned focused approach. When the combination of three tests was analyzed, at least one test accurately suggested a double adenoma in 80% of the patients; in 15% of the patients, no test was suggestive of a double adenoma and in 5% the sestamibi scan was false positive. CONCLUSIONS: This retrospective investigation documents that neither preoperative localization tests nor IOPTH assay accurately document double adenomas in patients with primary hyperparathyroidism. The combined accuracy of US, sestamibi, and IOPTH assay predicted a double adenoma in 80% of the patients.

Adenoma↗
PubMed2003

The helix-loop-helix protein, Id-1, is overexpressed and regulates growth in papillary thyroid cancer.

BACKGROUND: Members of the Id helix-loop-helix proteins are key regulators of cell growth and differentiation in a variety of cell types. They are also required for cell cycle progression and regulate tumor angiogenesis. Furthermore, deregulated expression of Id proteins has been observed in some human malignancies. Therefore we hypothesized that the Id-1 gene may play a role in papillary thyroid carcinogenesis. METHODS: Id-1 gene expression was characterized by Northern blot analysis and Id-1 immunohistochemistry in human thyroid tissue. Id-1 gene expression and regulation was evaluated in a human papillary thyroid cancer cell line, TPC-1, by Northern blot analysis. RESULTS: The Id-1 gene was significantly overexpressed in papillary thyroid cancer compared with normal thyroid tissue from the same patients (n = 18) by both Northern blot analysis and semiquantitative Id-1 immunohistochemistry (P <.001). Id-1 immunoreactivity was primarily localized to the cytoplasm of the thyroid follicular cells. In the TPC-1 cell line, stimulation by TSH and serum up-regulated Id-1 mRNA expression 1.5- and 4.0-fold, respectively. Activation of the mitogen intracellular protein kinase A and protein kinase C signaling pathways also up-regulated Id-1 mRNA expression. Inhibition of Id-1 mRNA expression with Id-1 antisense oligonucleotide inhibited growth compared with control Id-1 sense and random oligonucleotides (P <.05). CONCLUSIONS: The Id-1 gene is overexpressed in papillary thyroid cancer. Id-1 may play a role in the regulation of growth in papillary thyroid cancer.

Blotting, Northern↗
PubMed2003

Anaplastic thyroid cancer: cytogenetic patterns by comparative genomic hybridization.

We studied chromosomal abnormalities by comparative genomic hybridization (CGH) and flow cytometry in anaplastic thyroid cancer (ATC), and when present in coexisting or previous differentiated thyroid cancer (DTC). Overall 10 frozen tissues from patients with ATC and 5 cell lines (1 ATC and 4 DTCs) were analyzed. We found chromosomal abnormalities in 5 of 10 ATC tissues, with 24 abnormalities (22 gains and 2 losses). Among 8 ATCs that were associated with prior or concurrent DTC, more chromosomal abnormalities were found in ATC associated with follicular thyroid cancer (FTC) than those associated with PTC (median numbers 9.5 and 0.5, respectively, p = 0.046) or no associated differentiated thyroid cancer. Gain of 1q was relatively common in ATCs (30%). By flow cytometry, we found aneuploidy in 6 of 10 ATC tissues and diploidy in 4. There was concordance between DNA aneuploidy and the presence of chromosomal abnormalities by CGH in 4 of the 5 ATCs (p = 0.048). We also found 26 chromosomal abnormalities in an ATC cell line, 14.3 in 3 FTC cell line, and 3 in a PTC cell line. In conclusion, chromosomal abnormalities are frequent in ATCs associated with FTC, but uncommon in those associated with PTC and in ATCs with no associated differentiated thyroid cancer. These findings support the concept that PTC and FTC have different genetic backgrounds and, even after the transformation to ATC, they may retain some of their cytogenetic characteristics.

Adenocarcinoma, Follicular↗
PubMed2003

Chromosomal aberrations by comparative genomic hybridization in thyroid tumors in patients with familial nonmedullary thyroid cancer.

PURPOSE: Nonmedullary thyroid cancer is the most common form of thyroid cancer and its familial form (FNMTC) is increasingly recognized as a distinct clinical entity. However, the genetic background of FNMTC is still poorly understood and the causative gene(s) have not yet been identified. METHODS: Because comparative genomic hybridization allows for screening of the entire tumor genome simultaneously for chromosomal gains and/or losses without prior knowledge of potential aberrations, we used this technique in thyroid normal and neoplastic samples from FNMTC patients (1) to analyze whether chromosomal aberrations would correlate with inheritance pattern, and/or clinicopathologic features and (2) to compare comparative genomic hybridization (CGH) findings in familial tumors with those already known in sporadic differentiated thyroid cancers. RESULTS: No common germline or somatic chromosomal aberrations were observed in patients with FNMTC because the frequencies and most locations of chromosomal aberrations in familial tumors were also common in sporadic tumors. However, some somatic aberrations were only found in familial tumors (gains in 2q, 3q, 18p, and 19p). Common aberrations in familial tumors corresponded to several locations of candidate genes already reported for sporadic thyroid tumorigenesis. CONCLUSIONS: Our findings suggest that chromosomal aberrations in thyroid tumors in patients with FNMTC are not related to inheritance pattern but rather to tumorigenesis.

Adolescent↗
PubMed2003

Modulation of tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by chemotherapy in thyroid cancer cell lines.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many human cancer cells but not in normal cells. Thyroid cancer cells, however, appear to be relatively resistant to TRAIL-induced apoptosis. We therefore investigated the effect of chemotherapy on TRAIL-induced apoptosis in thyroid cancer cells. We used six thyroid cancer cell lines: TPC-1, FTC-133, FTC-236, FTC-238, XTC-1, and ARO82-1. We used flow cytometry to measure apoptosis, dimethyl-thiazol-diphenyltetrazolium bromide (MTT) assay to measure antiproliferation effects and Western blot to determine the expression of Bcl family proteins. Troglitazone, paclitaxel, geldanamycin, and cycloheximide were used for pretreatment. We used the Student's t test and analysis of variance (ANOVA) for statistical analysis. All thyroid cancer cell lines, except the TPC-1 cell line, were resistant to TRAIL, and growth inhibition was less than 20% at concentration of 800 ng/mL of TRAIL. In both TPC-1 (TRAIL-sensitive) and FTC-133 (TRAIL-resistant) thyroid cancer cell lines, pretreatment with troglitazone, cycloheximide, and paclitaxel enhanced TRAIL-induced cell death significantly but pretreatment with geldanamycin did not. There were no significant changes in Bcl-2, Bcl-xl, and Bax protein expression after troglitazone treatment. In conclusion, TRAIL in combination with troglitazone, paclitaxel, and cycloheximide induces apoptosis in thyroid cancer cells at suboptimal concentrations that cannot be achieved using TRAIL alone.

Antineoplastic Agents↗