Self-assembling peptide nanofiber as potential substrates in islet transplantation

Hypoxia and reoxygenation (H/R)-induced damage often happens soon after islets are transplantation. The process of islet isolation and purification causes the rapid onset of hypoxia. We sought to develop a functional scaffold to sustain the structure and function of islets as well as to recover some of the surface molecules damaged during isolation, seeking to improve islet transplantation outcomes. Self-assembling peptide nanofiber (SAPNF), a new type of substrate has been shown to be an excellent biological material for neuronal cell culture and tissue engineering in animals. In this study, we investigated the protective effect of SAPNF on damage to rat islets. Freshly prepared rat islets from male Sprague-Dawley rats were seeded in plates coated with (SAPNF-treated group) or without (control group) SAPNF. The islets were then divided into two groups culture under normoxia for 7 days versus exposure to hypoxia (< 1% O2) for 6 hours followed by reoxygenation for 24 hours. The results showed that SAPNF exhibited improving effects on viability and function of cultured islets, protecting the one from H/R-induced damage. In both groups, the stimulation index of SAPNF-treated groups were about two times the controls. SAPNF treatment decreased apoptotic rates of islet cells. These results suggested the usefulness of SAPNF to maintain the viability and function of rat pancreatic islets. SAPNF may be a potential scaffold for clinical islet transplantation.

Cloning, sequencing, and analysis of the full-length CDNA of rhesus monkey factor IX

OBJECTIVE

Coagulation factor IX (FIX) is a vitamin K-dependent serine protease, which plays a key role in the coagulation cascade. The rhesus monkey may be an indispensable substitute for humans in research of pig-to-human xenotransplantation, due to its close relationship. But the coagulation function concordance between rhesus monkey and human is unknown. In this study, we cloned the full-length cDNA of rhesus monkey FIX (rFIX) to investigate the genomic backgrounds of the coagulation systems.

METHOD

We cloned the full-length cDNA from the cDNA library of rhesus monkey liver tissue. Polymerase chain reaction was used to screen the positive clones. Based on a partial sequence obtained by cDNA library screening and a homologous sequence from the database, we designed a second pair of primers to obtain the full sequence. For further analysis of rFIX, we used several online ExPASy Proteomic tools.

RESULT

We obtained the full-length cDNA of rFIX, which has 2668 nucleotides, predicting an open reading frame of 1383 nucleotides corresponding to 461 amino acids. The deduced protein sequence indicated functional domains of signal peptide, Gla, two epidermal growth factor, and trypsin-like serine protease, which were consisted with those of human FIX (hFIX). Sequence alignments showed that rFIX is highly homologous to hFIX with nucleotide identity of 96% and amino acid identity of 97%.

CONCLUSION

We have report herein the full-length cDNA of rFIX. The high homology between rhesus monkey and human coagulation factor ensure the reliability and feasibility of rhesus monkey as a recipient in studies on coagulation disorders in xenotransplantation.

Biologic features and treatment outcome of secondary acute lymphoblastic leukemia--a review of 101 cases

BACKGROUND

Secondary acute lymphoblastic leukemia (sALL) is a rare disease and its biologic features are not well characterized.

PATIENTS AND METHODS

We describe a cohort of seven patients and discuss 94 additional cases from the literature for whom biological parameters were described. Cases with incomplete data were excluded.

RESULTS

Hodgkin's disease (HD) was more common in the 18-59 age group while breast and prostate cancers were prevalent only in the >or=18-year-old patients. The time interval to develop sALL was similar among all age groups but was significantly longer for HD and neuroblastoma primary diagnoses and sALL with complex karyotype. T-cell immunophenotype was more common in the <18 age group. Complete remission was infrequent in the >or=60 age group. The overall survival was poor for all sALL regardless of age, primary diagnoses, cytogenetic subgroups, or immunophenotype. Allogeneic transplantation most probably represents the only chance of cure.

CONCLUSION

Better identification of prognostic factors to prevent the occurrence of sALL is indicated.

P53 gene codon 72 polymorphism and risk of esophageal squamous cell carcinoma: a case/control study in a Chinese population

The aims of this study were to investigate whether p53 gene codon 72 polymorphism was a biomarker associated with esophageal squamous cell carcinoma (ESCC) and its relationship with smoking status in China. The p53 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism among 673 patients with ESCC and 694 healthy controls. The association between p53 genotypes and risk of developing ESCC was estimated by odds ratios (OR) and their 95% confidence intervals (CIs) computed by logistic regression. Compared with Arg/Arg homozygotes, Pro/Pro homozygotes had a nearly twofold increased risk (adjusted OR, 1.83; 95% CI, 1.35-2.48). For the Pro/Arg heterozygotes, there was no evident increased risk (adjusted OR, 1.01, 95% CI, 0.78-1.30). Furthermore, the risk associated with the Pro/Pro variant genotype was more pronounced in younger patients at diagnosis (= 45 years) (OR, 7.4; 95% CI, 1.44-37.89, P = 0.02), in women (OR, 3.15; 95% CI, 1.52-4.53, P = 0.02) and in non-smokers (OR, 2.49; 95% CI, 1.58-3.94) and light smokers (OR, 2.13; 95% CI, 1.15-3.93). But tests for homogeneity between smoking-related OR showed no significant differences (P = 0.4). The p53 gene codon 72 Pro/Pro genotype was significantly associated with the increased risk of ESCC in a Chinese mainland population and may be an independent factor in susceptibility to ESCC. The association was especially noteworthy in women and in younger patients.

[Promising new treatment options for metastatic androgen-independent prostate cancer]

OBJECTIVE

Review the recent advances in the treatment of androgen independent prostate cancer (AIPC).

METHODS

Review recent abstracts and literature utilizing Medline/PubMed using key words: androgen independent/hormone refractory prostate cancer, novel treatment options, Phase II, III trials and meeting abstracts/presentations.

CONCLUSION

Two pivotal trials SWOG (Southwest Oncology Group) study 9916 and Taxotere 327 have shown that survival can be improved in this population by administration of chemotherapy with docetaxel every three weeks intravenously. An overall survival of 19 months could be achieved with docetaxel/prednisone compared to 16 months with mitoxantrone/prednisone. Despite this, there is a need to improve on this survival benefit because the relapse free survival among responders is often short (6 months) and patients often would have progression of their cancer leading to death. Satraplatin, a novel platinum analogue had been found to provide an additional 1.5 week progression free survival benefit in this population in the second line setting. There is however, a need to develop less toxic drugs that would improve survival significantly.

RF-powered BIONs for stimulation and sensing

Virtually all bodily functions are controlled by electrical signals in nerves and muscles. Electrical stimulation can restore missing signals but this has been difficult to achieve practically because of limitations in the bioelectric interfaces. Wireless, injectable microdevices are versatile, robust and relatively inexpensive to implant in a variety of sites and applications. Several variants are now in clinical use or under development to perform stimulation and/or sensing functions and to operate autonomously or with continuous coordination and feedback control.

Survival and treatment morbidity with therapeutic lymphadenectomy for regional nodal metastases from melanoma

8571

Background: Therapeutic lymphadenectomy (TL) is potentially curative therapy for clinically palpable nodal metastatic melanoma. However, TL is associated with significant morbidity and a dismal prognosis. Methods: Review of the melanoma database identified 275 patients who underwent TL. Patient, tumor, and treatment-related variables associated with recurrence and overall survival were analyzed. Results: The study group comprised of 63% males with a nodal basin distribution of 47% axilla, 35% groin and 18% neck. Median age, number of positive lymph nodes and size of the largest lymph node were 51 years 2 nodes and 2.5 cm respectively. Median survival was 27.4 months (77%, 55% and 34% at 1, 2 and 5-years respectively). Regional recurrence at the lymphadenectomy site occurred in 76 (28%) patients. Distant metastases developed in 67 (88%) patients with and 126 (63%) without regional recurrence. On multivariate analysis, the most powerful predictor of both survival and regional recurrence was lymph node ratio (LNR- number of positive nodes/total dissected nodes). Median survival for LNR <0.13 was 39 months versus 19 months for ≥0.13 (p = 0.005). Older age and male sex were also predictive of a decreased survival. Treatment-related morbidity was rare and included lymphedema (12%), wound complications (3%) and nerve injury (1%). Conclusion: The overall survival and acceptable morbidity justifies TL for clinically positive nodal metastatic melanoma. LNR is predictive of survival and regional recurrence following TL. Due to significant distant and regional failure rates, in addition to systemic adjuvant therapy these patients may benefit from radiation therapy.

No significant financial relationships to disclose.

A phase II trial of 17-allylamino-17-demethoxygeldanamycin (17-AAG) in patients with hormone-refractory metastatic prostate cancer

15553

Background: 17-Allylamino-17-Demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic with anti- proliferative activity in several mouse xenograft models including prostate cancer models. Serum IL-6, IL-8, and maspin are potentially important markers of prostate cancer biology. Methods: Patients (pts) with metastatic, hormone-refractory prostate cancer progressing on at least one prior systemic therapy with rising PSA were eligible. All pts received 17-AAG at a dose of 300 mg/m2 IV weekly for three out of four weeks. Primary objective was to assess the PSA response (50% decrease in PSA). Secondary objectives included Adverse Events (AEs) and correlative serum markers including IL-6, IL-8 and maspin levels. A Simon two-stage design required a total of 25 pts with early termination if < 2 responses occurred among the 1st 16 eligible patients. Results: Seventeen pts were enrolled of which 15 were deemed eligible. Median age was 68 and median PSA was 252 ng/mL. Pts received 17-AAG for a median number of 2 cycles. No pt had a PSA response. No grade 4/5 AEs occurred. Grade 3 AEs included fatigue (4 pts), lymphopenia (2 pts) and back pain (2 pts). The median PSA progression free survival was 1.8 months (95% CI: 1.3–3.4 months). The six-month overall survival was 61% (95% CI: 37%-100%). Due to the lack of PSA response, accrual was stopped per study design. At day 15, the median IL-6 and IL-8 increase from baseline was 0.4 pg/ml (p=0.57) and 3 pg/ml (p=0.73), respectively. Maspin levels had day 15 increase of 6-fold (p=0.44). At treatment failure (TF), the median IL-6 increase from baseline was 4.47 pg/ml (p=0.03) and IL-8 decrease was 1.8 pg/ml (p=0.31). Maspin levels had a 29-fold increase at TF (p=0.09). Conclusions: 17-AAG did not show any activity with regards to PSA response. Serum IL-6 was significantly increased at the time of TF. Further evaluation of 17-AAG at a dose of 300 mg/m2 IV weekly in this patient population is not warranted.

No significant financial relationships to disclose.

The effect of androgen deprivation on mini-mental status examination in patients with biochemical recurrence of prostate cancer

15592

Background: Androgen deprivation (AD) is a common treatment option for asymptomatic patients with biochemical recurrence of prostate cancer. Side effects such as sexual dysfunction, hot flashes, fatigue and gynecosmastia have been well documented. However, some of the side effects such as osteoporosis, insulin resistance, hyperglycemia, and anemia have only been recently recognized. The effects of AD on memory are not known. Aim: To determine if there is a decline in cognitive function(CF) in patients on AD using the modified MiniMental Status examination (MMSE). This test was chosen because it was simple, easy to administer and reproducible. Methods: We prospectively enrolled men with biochemical recurrence of prostate cancer prior to initiation of AD and monitored their MMSE at baseline, 2 ,and 4 months and while on AD (Mayo Clinic Jacksonville 8/2004- 9/2006). Results: 38 men were enrolled,however, only 20 men had at least 3 MMSE testing done. (5 withdrew consent, 13 had missing MMSE or lost to followup). The mean age was 68 years, mean baseline MMSE score was 27 and none had a clinical diagnosis of dementia or depression. Comparing the first MMSE and the 2nd MMSE score 19/20 patients had no decline of CF except for one patient who had a transient decline of 5 points in his MMSE score during a period of depression ,however, he had subsequent recovery of his score back to his normal baseline 27. Comparing the first and third MMSE score 20/20 patients had no decline of CF. The mean score change in MMSE score was -1 in 3 patients, 0 in 9 patients, +1 in 4 patients, +2 in 2 patients and +3 in 2 patients. There was no decline of 3 or more points in the mean score in any patient. Interestingly, 2 patients had an 3 point improvement of their MMSE score. We felt that it was secondary to being more familiar to the test process and not due to AD. Conclusions: There is no significant decline in MMSE score in men on AD at 2 and 4 months. MMSE might not be able to detect subtle changes in memory therefore, further study with more sensitive test to discriminate CF decline would be warranted and with longer followup cognitive impairement may be more evident.

No significant financial relationships to disclose.

Complications and effectiveness of combination chemotherapy in metastatic colorectal cancer (MCRC) with unresected primary (UP)

14537

Background: The outcome of patients (pts) with MCRC and unresected primary (UP) has not been studied systematically in the modern era of targeted and combination chemotherapy. We conducted a single institute retrospective study to determine the rate and nature of complications in this population. Methods: MCRC-UP pts treated at Roswell Park Cancer Institute between 2002 and 2006 were identified. Demographic, toxicity, efficacy, and palliative intervention data were collected. Primary tumor related complications including obstructive symptoms, bleeding, perforation, and fistulas were assessed. Results: 24 pts with colonic UP were identified. 14/24 were treated with bevacizumab-based chemotherapy (11 FOLFOX, 3 capecitabine), 7/24 with FOLFOX, 2 with capecitabine, and 1 with FOLFIRI. No perforations, hemorrhagic events, or arterial events were noted. None of the 24 pts required palliative surgical intervention secondary to the UP. Only 2 pts developed obstructive symptoms and 1 pt developed an entero-cutaneous fistula; all 3 events were attributed to peritoneal carcinomatosis. 10 pts with rectal UP were identified. 1 pt received upfront chemoradiation followed by 5-FU/bevacizumab. 9/10 pts were treated with upfront systemic chemotherapy (6 bevacizumab-based [5 FOLFOX, 1 capecitabine], 3 FOLFOX). Of these 9 pts, 4 required subsequent palliative radiation therapy for obstructive symptoms (3 pts) or pain (1pt) while 5 continue on systemic chemotherapy (median 1st line chemotherapy duration > 7 months). No perforations, bleeding requiring transfusion, or arterial events were noted among the rectal cancer population. 1 pt required a diverting colostomy for obstruction despite palliative CRT. Median time to progression on first line chemotherapy was 7.4 months for colon cancer and 8 months for rectal cancer. The median overall survival was 13.6 months for colon cancer and has not been reached for rectal cancer (exceeded 13 months). Conclusion: Treatment of MCRC with UP is feasible and is rarely associated with complications related to the primary tumor. Rectal cancer with UP can be managed with upfront chemotherapy. Subsequent palliative RT is needed in about 50% of these pts.

No significant financial relationships to disclose.

Construction and Characterization of a cDNA Library from Liver Tissue of Chinese Banna Minipig Inbred Line

A xenograft that performs efficient functions is an essential premise for successful xenotransplantation. Our early study indicated that Chinese Banna minipig inbred line (BMI) was an ideal xenograft donor. However, the activities of some proteins synthesized by the BMI liver are different from the human, which could lead to functional disorders in coagulation, fibrinolysis, and anticoagulation after liver xenotransplantation. Therefore, it is important to investigate the genetic background of protein incompatibility and to provide new strategies for gene manipulation. In this study we constructed a cDNA expression library using BMI liver tissue to obtain an understanding of nucleic acid and protein differences between the two species. We extracted total RNA and purified mRNA of the liver tissue from one of the sixteenth inbred generation of BMI/JS 151 substrain. After double-strand cDNA synthesis, we fractionated it on a CHROMA APIN-400 column; ligated the longer than 500bp cDNA into a ZAP Express Vector; and performed a lambda: phage packaging reaction, library amplification, and titer. We randomly picked 12 plaques and tested the length of inserts. The titers of the primary and amplified libraries were 1.0 x 10(6) pfu/mL and 5.0 x 10(9) pfu/mL, respectively. The percentages of recombinants were 97.0% in the primary library and 98.0% in the amplified library. The lengths of most inserts were between 750 bp and 2.0 kb. Thus, we successfully constructed a cDNA expression library from BMI liver tissue. Using the library, we hope to get a full-length cDNA of some important genes and conduct further studies on porcine liver function in xenotransplantation.

Functional reconstitution of purified chloroquine resistance membrane transporter expressed in yeast

Malaria is one of the major parasitic diseases. Current treatment of malaria is seriously hampered by the emergence of drug resistant cases. A once-effective drug chloroquine (CQ) has been rendered almost useless. The mechanism of CQ resistance is complicated and largely unknown. Recently, a novel transmembrane protein, Plasmodium falciparum chloroquine resistance transporter (PfCRT), has fulfilled all the requirements of being the CQ resistance gene. In order to elucidate the mechanism how PfCRT mediates CQ resistance, we have cloned the cDNA from a CQ sensitive parasite (3D7) and tried to express it in Pichia pastoris (P. pastoris) but with unsuccessful results due to AT-rich sequences in the malaria genome. We have therefore, based on the codon usage in P. pastoris, chemically synthesized a codon-modified pfcrt with an overall 55% AT content. This codon-modified pfcrt has now been successfully expressed in P. pastoris. The expressed PfCRT has been purified with immuno metal affinity chromatography (IMAC) and then reconstituted into proteoliposome. It was found that proteoliposomes have a saturable, concentration and time-dependent CQ transport activity. In addition, we found that proteoliposomes with resistant PfCRT(r) (K76T or K76I) showed an increased CQ transport activity compared to liposomes with lipid alone, or proteoliposomes reconstituted with sensitive PfCRT(s) (K76) protein. This activity could be inhibited by nigericin and decreased with the removal of Cl(-). This work suggests that PfCRT is mediating CQR in P. falciparum by virtue of its changes in CQ transport activity depending on pH gradient and chloride ion in the food vacuole.

Quality of life intervention for men with biochemical recurrence of prostate cancer

18585

Background: The Quality of life (QOL) and psychosocial needs of the 30–40% of prostate cancer patients who experience biochemical recurrence are not known. The impact of having a rising PSA, anticipation of undergoing PSA testing, and living with prostate cancer may increase psychological distress and decrease QOL. Aim: to evaluate the psychosocial treatment needs of men with biochemical recurrence of prostate cancer (br-PCa) and to develop a treatment to address these needs. Methods: 28 men with br-PCa, 58–87 years, were enrolled. A qualitative research approach was used, consisting of six, 2 hour, semi-structured, focus groups containing 4–6 men per group. Data were content coded and grouped into categories following the structure of the focus group guide. The major conceptual themes were then summarized by 2 independent reviewers. Discrepancies were discussed with a third researcher until a consensus was reached. These results were used to guide development of a multi-disciplinary quality of life intervention. Results: Participants defined QOL as the ability to stay active both physically and mentally without limitation in the performance of usual activities. There was a consensus that prostate cancer led to substantial anxiety related to PSA testing, treatment side effects, and fear of recurrence. Participants were enthusiastic about receiving adjuvant multidisciplinary treatment for prostate cancer focusing on anxiety management, nutrition, exercise, management of treatment side effects, and medical education. Participants desired a male group leader and feedback was mixed regarding whether spouses should be involved. Conclusions: Men with br-PCa report experiencing substantial anxiety and were enthusiastic about receiving a structured intervention to these needs. Based on our findings an intervention has been developed and is currently being compared to usual care.

No significant financial relationships to disclose.

Functional polymorphisms in cell death pathway genes FAS and FASL contribute to risk of lung cancer

BACKGROUND

The FAS and FASL system plays a key role in regulating apoptotic cell death and corruption of this signalling pathway has been shown to participate in immune escape and tumorigenesis. There is reduced expression of FAS but elevated expression of FASL in many types of human cancers including lung cancer. We recently reported an association between functional polymorphisms in FAS (-1377G-->A) and FASL (-844T-->C) and risk of oesophageal cancer.

OBJECTIVE

To examine the contribution of these polymorphisms to risk of developing lung cancer.

METHODS

Genotypes of 1000 lung cancer patients and 1270 controls were analysed by PCR based restriction fragment length polymorphism. Associations with risk of lung cancer were estimated by logistic regression.

RESULTS

Compared with non-carriers, there was a 1.6 fold excess risk of developing lung cancer for carriers of the FAS -1377AA genotype (odds ratio (OR) 1.59, 95% confidence interval (CI) 1.21 to 2.10; p = 0.001), and 1.8 fold excess risk (OR 1.79, 95% CI 1.26 to 2.52; p = 0.001) for carriers of FASL -844CC. Gene-gene interaction of FAS and FASL polymorphisms increased risk of lung cancer in a multiplicative manner (OR for the carriers of both FAS -1377AA and FASL -844CC genotypes 4.18, 95% CI 2.83 to 6.18). Gene-environment interaction of FAS or FASL polymorphism and smoking associated with increased risk of lung cancer was also found.

CONCLUSION

These results are consistent with our initial findings in oesophageal cancer and further support the hypothesis that the FAS and FASL triggered apoptosis pathway plays an important role in human carcinogenesis.

A novel T-77C polymorphism in DNA repair gene XRCC1 contributes to diminished promoter activity and increased risk of non-small cell lung cancer

X-ray repair cross-complementing 1 (XRCC1) plays a key role in DNA base excision repair and cells lacking its activity are hypersensitive to DNA damage. Recently, we reported a SNP (rs3213245, -77T>C) in the XRCC1 gene 5' untranslated region (UTR) was significantly associated with the risk of developing esophageal squamous-cell carcinoma. Computer analysis predicted that this SNP was in the core of Sp1-binding motif, which suggested its functional significance. Gel shift and super shift assays confirmed that -77T>C polymorphic site in the XRCC1 promoter was within the Sp1-binding motif and the T>C substitution greatly enhanced the binding affinity of Sp1 to this region. Luciferase assays indicated that the Sp1-high-affinity C-allelic XRCC1 promoter was associated with a reduced transcriptional activity. The association between -77T>C and three other amino-acid substitution-causing polymorphisms in XRCC1 and risk of lung cancer was examined in 1024 patients and 1118 controls and the results showed that only the -77T>C polymorphism was significantly associated with an increased risk of developing lung cancer. Multivariate logistic regression analysis found that an increased risk of lung cancer was associated with the variant XRCC1 -77 genotypes (TC and CC) compared with the TT genotype (OR=1.46, 95% CI=1.18-1.82; P=0.001) and the increased risk was more pronounced in smokers (OR=1.63, 95% CI=1.20-2.21) than in non-smokers (OR=1.28, 95% CI=0.94-1.76). Taken together, these results showed that the functional SNP -77T>C in XRCC1 5'UTR was associated with cancer development owing to the decreased transcriptional activity of C-allele-containing promoter with higher affinity to Sp1 binding.

Parathyroid carcinoma: a case series

INTRODUCTION

We present 3 patients with parathyroid carcinoma and describe their presentations, clinical profiles, and management.

MATERIALS AND METHODS

A case series review of medical records.

RESULTS

Two women and 1 man (age range, 32 to 57 years) had parathyroid cancer and primary hyperparathyroidism (PHPT). One patient presented with osteitis fibrosa, 1 with renal stone and a neck mass, and 1 with recurrence of PHPT after excision of supposedly benign parathyroid adenoma 4 years ago. All had severe hypercalcaemia and elevated parathyroid hormone levels that ranged from 4 to 43 times above the normal range. Exploration of the neck clearly identified 1 parathyroid tumour with local invasion; 2 other specimens showed capsular and vascular invasion on frozen section and final histology. All 3 patients underwent parathyroidectomy and ipsilateral hemithyroidectomy. Parathyroid size ranged from 1.3 to 4 cm and no lymph node metastasis was identified. No patient had tumour recurrence after a follow-up period of 1 year.

CONCLUSION

Parathyroid carcinoma is a rare endocrine malignancy. Suspicious features include marked hypercalcaemia, neck mass, and local recurrence. Parathyroidectomy with ipsilateral hemithyroidectomy and nodal clearance gives the best chance of reducing local tumour recurrence.

A common polymorphism in the 3'UTR of cyclooxygenase 2/prostaglandin synthase 2 gene and risk of lung cancer in a Chinese population

Cyclooxygenases (COXs) are key enzymes that convert arachidonic acid to prostaglandins. Overexpression of COX-2, one of the COX isozymes, has been shown to be an early event in lung carcinogenesis and may play an important role in lung cancer development. A common single nucleotide polymorphism, T8473C, located within a potential functional region in the 3'UTR of COX-2 gene was identified and we hypothesized that this COX-2 variant is associated with lung cancer risk. To test this hypothesis, we genotyped this variant in a case-control study of 322 histologically-confirmed lung cancer patients and 323 age and sex frequency-matched cancer-free controls in a Chinese population. The results showed that the frequencies of variant genotypes 8473CT/CC were significantly less common in the cases (27.3%) than in the controls (35.3%) (P=0.034), suggesting that the 8473C allele was protective against lung cancer. Multivariate logistic regression analyses revealed that the COX-2 variant genotypes (8473CT/CC) were associated with a significantly decreased risk of lung cancer compared with the 8473TT wild-type homozygotes (OR=0.64, 95% CI=0.45-0.92). When we defined the reference group as non-smokers having the 8473CT/CC variant genotypes, the smokers with the 8473TT wild-type genotype had the greatest risk (adjusted OR=5.28, 95% CI=3.10-9.00). These findings indicate that the COX-2 T8473C polymorphism may contribute to lung cancer susceptibility in the Chinese population. Further larger molecular epidemiological studies are warranted to confirm these findings.