A 3'-Untranslated Region Polymorphism in IGF1 Predicts Survival of Non-Small Cell Lung Cancer in a Chinese Population

Downregulation of lncRNA H19 sensitizes melanoma cells to cisplatin by regulating the miR-18b/IGF1 axis

Long noncoding RNAs (LncRNAs) lncRNA H19 has been shown to be involved in the chemotherapy resistance of cancer cells. However, the role of lncRNA H19 in chemotherapy resistance of melanoma cells remains unknown. Here, we determined lncRNA H19, miR-18b, and insulin-like growth factor 1 (IGF1) expression by utilizing quantitative real-time PCR. Cell proliferation ability and chemosensitivity were assessed by colony formation assay and MTT assay. Flow cytometry assay was applied to detect cell apoptosis. We discovered that lncRNA H19 was upregulated, but miR-18b was downregulated in melanoma tissues and cisplatin (DDP)-resistant melanoma cells. The overall survival for the group with lower lncRNA H19 was significantly better than the group with higher H19. IGF1 mRNA level was higher in melanoma tissues than that in normal tissues. miR-18b expression level A negative correlation was observed between the expression levels of miR-18b, lncRNA H19, and IGF1 mRNA. Functionally, knockdown of lncRNA H19 sensitized resistant A375/DDP and M8/DDP cells to DDP. Silencing lncRNA H19 inhibited colony formation ability and promoted apoptosis of DDP-resistant melanoma cells, which was abrogated by miR-18b inhibition and IGF1 upregulation. Mechanistically, lncRNA H19 directly interacted with miR-18b to regulate its expression. IGF1 was identified as a target of miR-18b. These findings highlight the fact that lncRNA H19 could influence DDP-resistance by modulating the miR-18b/IGF axis in melanoma cells, suggesting a new potential therapeutic target for melanoma patient treatment.

Hormonal factors in association with lung cancer among Asian women: A pooled analysis from the International Lung Cancer Consortium

Two thousand sixty-four lung cancer cases and 5342 controls were evaluated in this International Lung Cancer Consortium (ILCCO) pooled analysis on estrogen-related hormonal factors and lung cancer in Asian women. Random effect of study site and fixed effect of age, smoking status, comprehensive smoking index and family history of lung cancer were adjusted for in the multivariable logistic regression models. We found that late onset of menarche conferred elevated odds of lung cancer with adjusted odds ratio (OR) of 1.24 (95% confidence interval [CI] = 1.05, 1.45) for 17 years or older, compared to 14 years or younger. Late onset of menopause at 55 years old or older was associated with lung cancer with OR = 1.24 (95% CI = 1.02, 1.51). Nonnatural menopause was associated with an OR of 1.39 (95% CI = 1.13, 1.71). More live births showed reversed association with lung cancer (ORs of 5 or more live births: 0.71 (95% CI = 0.60, 0.84), compared to 0-2 live births (P_trend < 0.001). A later first child delivery seemed associated with an increased susceptibility: OR of 21 to 25 years old: 1.23 (95% CI = 1.06, 1.40), 26 or older: 1.27 (95% CI = 1.06, 1.52), P_trend = .010). The use of oral contraceptives appeared to be protective with an OR of 0.69 (95% CI = 0.57, 0.83). Stronger for adenocarcinoma than squamous cell carcinoma, these relationships were not clearly modified by smoking status, probably because of lower prevalence of smoking. This is a first and largest pooling study of lung cancer among Asian women and the results suggested potential roles of hormone-related pathways in the etiology of this disease.

Relationship between insulin-like growth factor axis gene polymorphisms and clinical outcome in advanced gastric cancer patients treated with FOLFOX

The insulin-like growth factor (IGF) axis plays a crucial role in proliferation, differentiation, migration, angiogenesis, and apoptosis. The present study evaluated the associations between IGF axis single-nucleotide polymorphisms (SNPs) and clinical outcomes in advanced gastric cancer (AGC) patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX). A total of 190 patients undergoing FOLFOX chemotherapy for AGC were considered eligible for this study. Forty-four SNPs of 10 IGF axis genes were genotyped. Levels of serum IGF1 were measured using enzyme-linked immunoassays. SNPs of the IGF1R (rs12423791), and IGF1 (rs2162679, rs5742612, rs35767) genes were significantly associated with tumor response to FOLFOX. SNPs of rs4619 and rs17847203 were significantly associated with PFS (hazard ratio [HR] 0.575, 95% CI 0.385–0.858, P = 0.007; and HR 2.530, 95% CI 1.289–4.966, P = 0.007; respectively). SNPs of rs2872060 were significantly associated with OS—OS was shorter in patients carrying the TT variant than in those with the GG/GT genotypes (HR, 1.708, 95% CI 1.024–2.850, P = 0.040). The GT genotype of rs12847203 was also identified as an independent prognostic factor (HR 2.087, 95% CI 1.070–4.069, P = 0.031). These results suggest that IGF axis-pathway SNPs could be used as prognostic biomarkers of the outcome of FOLFOX chemotherapy in AGC patients. This information may facilitate identification of population subgroups that could benefit from IGF1R-targeted agents.

Insulin-Like Growth Factor (IGF) Pathway Targeting in Cancer: Role of the IGF Axis and Opportunities for Future Combination Studies

Despite a strong preclinical rationale for targeting the insulin-like growth factor (IGF) axis in cancer, clinical studies of IGF-1 receptor (IGF-1R)-targeted monotherapies have been largely disappointing, and any potential success has been limited by the lack of validated predictive biomarkers for patient enrichment. A large body of preclinical evidence suggests that the key role of the IGF axis in cancer is in driving treatment resistance, via general proliferative/survival mechanisms, interactions with other mitogenic signaling networks, and class-specific mechanisms such as DNA damage repair. Consequently, combining IGF-targeted agents with standard cytotoxic agents, other targeted agents, endocrine therapies, or immunotherapies represents an attractive therapeutic approach. Anti-IGF-1R monoclonal antibodies (mAbs) do not inhibit IGF ligand 2 (IGF-2) activation of the insulin receptor isoform-A (INSR-A), which may limit their anti-proliferative activity. In addition, due to their lack of specificity, IGF-1R tyrosine kinase inhibitors are associated with hyperglycemia as a result of interference with signaling through the classical metabolic INSR-B isoform; this may preclude their use at clinically effective doses. Conversely, IGF-1/IGF-2 ligand-neutralizing mAbs inhibit proliferative/anti-apoptotic signaling via IGF-1R and INSR-A, without compromising the metabolic function of INSR-B. Therefore, combination regimens that include these agents may be more efficacious and tolerable versus IGF-1R-targeted combinations. Herein, we review the preclinical and clinical experience with IGF-targeted therapies to-date, and discuss the rationale for future combination approaches as a means to overcome treatment resistance.

Genetic variation in IGF1 predicts renal cell carcinoma susceptibility and prognosis in Chinese population

Insulin-like growth factor 1 (IGF1) and IGF binding protein 3 (IGFBP3) play an important role in the development and progression of renal cell carcinoma (RCC). We evaluated the association of functional polymorphisms in IGF1 and IGFBP3 with susceptibility and prognosis of RCC. We genotyped nine potentially functional polymorphisms in IGF1 and IGFBP3 and assessed their association with risk of RCC in a two-stage case-control study compromising 1027 cases and 1094 controls, and with prognosis in a cohort of 311 patients. We found rs5742714 in the 3'-UTR of IGF1 was significantly associated with risk and prognosis of RCC. In the combined set, the rs5742714 GC/CC genotypes were significantly associated with decreased risk of RCC compared with the GG genotype (OR = 0.82; 95% CI = 0.68-0.98, P = 0.002). Furthermore, patients with the rs5742714 GC/CC genotypes showed improved survival than those with the GG genotype (Log-rank P = 0.025, HR = 0.36, 95% CI = 0.14-0.93). Besides, the rs5742714 GC/CC genotypes were associated with significantly decreased expression of IGF1 mRNA and lower IGF1 serum levels. Moreover, the luciferase reporter assays revealed the potential effect of rs5742714 genotype on the binding of microRNAs to IGF1. Our findings suggest that the IGF1 polymorphism rs5742714 may be a genetic predictor of susceptibility and prognosis of RCC.

Genetic polymorphisms modify bladder cancer recurrence and survival in a USA population-based prognostic study

OBJECTIVE

To identify genetic variants that modify bladder cancer prognosis focusing on genes involved in major biological carcinogenesis processes (apoptosis, proliferation, DNA repair, hormone regulation, immune surveillance, and cellular metabolism), as nearly half of patients with bladder cancer experience recurrences reliable predictors of this recurrent phenotype are needed to guide surveillance and treatment.

PATIENTS AND METHODS

We analysed variant genotypes hypothesised to modify these processes in 563 patients with urothelial-cell carcinoma enrolled in a population-based study of incident bladder cancer conducted in New Hampshire, USA. After diagnosis, patients were followed over time to ascertain recurrence and survival status, making this one of the first population-based studies with detailed prognosis data. Cox proportional hazards regression was used to assess the relationship between single nucleotide polymorphisms (SNPs) and prognosis endpoints.

RESULTS

Patients with aldehyde dehydrogenase 2 (ALDH2) variants had a shorter time to first recurrence (adjusted non-invasive hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.29-2.78). There was longer survival among patients with non-invasive tumours associated with DNA repair X-ray repair cross-complementing protein 4 (XRCC4) heterozygous genotype compared with wild-type (adjusted HR 0.53, 95% CI 0.38-0.74). Time to recurrence was shorter for patients who had a variant allele in vascular cellular adhesion molecule 1 (VCAM1) and were treated with immunotherapy (P interaction < 0.001).

CONCLUSIONS

Our analysis suggests candidate prognostic SNPs that could guide personalised bladder cancer surveillance and treatment.

Genetic variations in monocarboxylate transporter genes as predictors of clinical outcomes in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is characterized by poor prognosis and only a few molecular markers may be potentially used to predict clinical outcomes. Previous studies have demonstrated that monocarboxylate transporters (MCTs) play important roles in the development and progression of many cancers. The purpose of this study was to assess the effects of single nucleotide polymorphisms (SNPs) of MCT genes on prognosis of NSCLC patients in Chinese Han population. Nine functional SNPs in MCT1, MCT2, and MCT4 genes were selected and genotyped using Sequenom iPLEX genotyping system in 500 Chinese NSCLC patients receiving surgery. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the prognostic analysis. TT genotype of SNP rs1049434 (MCT1) was significantly associated with better overall survival (OS) (HR = 0.56, P = 0.026) and recurrence-free survival (RFS) (HR = 0.57, P = 0.016) of NSCLC patients. TT genotype of another SNP rs995343 (MCT2) exhibited an association with worse RFS of NSCLC patients (HR = 1.46, P =  .039). Unfavorable genotypes of SNP rs1049434 and rs995343 showed a significant cumulative effect on OS and RFS of NSCLC patients. Moreover, we found that patients carrying AA+AT genotypes of rs1049434 showed significant OS and RFS benefits from adjuvant chemotherapy, but those with TT genotype did not. Our findings suggest that SNPs in MCT1 and MCT2 genes may affect clinical outcomes and can be used to predict the response to adjuvant chemotherapy in NSCLC patients who received surgical treatment once validated in future study.

Genetic variants in genes of tricarboxylic acid cycle key enzymes are associated with prognosis of patients with non-small cell lung cancer

INTRODUCTION

Non-small cell lung cancer (NSCLC) is characterized by poor prognosis and only a few molecular markers may be potentially used to predict the outcome. Metabolic reprogramming is a hallmark of cancer, including the alterations of tricarboxylic acid (TCA) cycle key enzymes. However, the significance of single nucleotide polymorphisms (SNPs) in genes encoding these key enzymes has not been investigated in NSCLC.

PATIENTS AND METHODS

In this study, we genotyped 18 potentially functional SNPs in 7 genes belonging to 3 TCA cycle enzyme families (SDH, FH and IDH) using Sequenom iPLEX genotyping system in a cohort of 500 NSCLC patients. Multivariate Cox proportional hazards model and Kaplan-Meier curve were used for the survival analysis.

RESULTS

Our results showed that SDHC gene: SNP rs12064957, IDH2 gene: SNP rs11540478 and FH gene: SNP rs1414493 were associated with overall survival (OS) and SDHA gene: SNP rs13173911, IDH2 gene: SNP rs4932158 were associated with recurrence-free survival (RFS) of NSCLC patients. Unfavorable genotypes of these SNPs showed a significant cumulative effect on OS and RFS of NSCLC patients (both P<0.001). Furthermore, survival tree analysis indicated that FH: rs1414493 was the primary risk factor contributing to OS of NSCLC patients and the IDH2: rs4932158 was the primary risk factor contributing to RFS of NSCLC patients.

CONCLUSION

Our data suggest that SNPs in TCA cycle key enzyme genes may serve as potential biomarkers to predict the outcomes of NSCLC. Further studies with different ethnicities are needed to validate our findings and generalize their clinical utility.

Genetic variations in SLC3A2/CD98 gene as prognosis predictors in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is characterized by poor prognosis and only a few molecular markers may be potentially used to predict the risk of progression. This study aims to assess the effects of single nucleotide polymorphisms (SNPs) in the CD98 gene on prognosis of NSCLC patients. We genotyped three potential functional SNPs in CD98 gene using Sequenom iPLEX genotyping system in a cohort of 482 NSCLC patients. Multivariate cox proportional hazards model and Kaplan-Meier curve were used for the survival analysis. The variant-containing genotypes of rs1059292 in 5'-flanking region of CD98 gene were significantly associated with an increased risk of death in the multivariate analysis (Hazard ratio [HR], 1.49; 95% confidence interval [95% CI]: 1.04-2.14 in a dominant model). In stratified analysis, the association remained significant in patients with poor differentiation (HR=1.81, 95% CI=1.01-3.25). In addition, rs1059292 also showed a borderline significant association with T stage (OR=1.49; 95% CI: 0.96-2.35) and N stage (OR=1.53; 95% CI: 0.98-2.39). Functional analysis demonstrated that variant genotype of SNP rs1059292 significantly enhanced the transcription activity of CD98 gene promoter. Our data suggest that genetic variation of rs1059292 in CD98 gene may affect clinical outcome of NSCLC in Chinese population.

Genetic polymorphisms in IGF-I and IGFBP-3 are associated with prostate cancer in the Chinese population

Insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) are members of the insulin-like growth factor (IGF) family that play important roles in carcinogenesis. We hypothesized that the functional polymorphisms in IGF-I and IGFBP-3 may be associated with the risk of prostate cancer (PCa) in the Chinese population. This hospital-based case-control study included 664 PCa patients and 702 cancer-free controls. Nine SNPs in IGF-I and IGFBP-3 were genotyped using the TaqMan assay. The genetic associations between the pathogenesis and progression of PCa were assessed by logistic regression. We found that the genotype and allele frequency distribution of rs6218, rs35767 and rs5742612 were significantly different when comparing PCa cases to controls (P  = 0.005, 0.005 and 0.020, respectively). In the combined analysis, individuals with 2–6 risk alleles had an elevated risk of PCa compared to those with 0–1 risk alleles. We also found that the association between the combined risk alleles and the risk of PCa appeared stronger in the following subgroups: individuals older than 71 years of age (OR  = 1.41, 95%CI  = 1.05–1.91, P  = 0.020), nonsmokers (OR  = 1.68, 95%CI  = 1.21–2.32, P  = 0.002), nondrinkers (OR  = 1.32, 95%CI  = 1.02–1.61, P  = 0.002), and those with a negative family history of PCa (OR  = 1.28, 95%CI  = 1.02–1.71, P  = 0.022). Our results indicate that the three SNPs (rs6218, rs35767 and rs5742612) and the joint genotypes with 2–6 risk alleles, may contribute to the susceptibility to PCa, but not the progression, in the Chinese population.

Insulin-like growth factor receptor polymorphism defines clinical outcome in estrogen receptor-positive breast cancer patients treated with tamoxifen

Compelling evidence points to a key role for insulin-like growth factor 1 (IGF1) signaling in breast cancer development and progression. In addition, IGF1 receptor (IGF1R) expression has been correlated and functionally linked with estrogen receptor (ER) signaling. Recent translational studies support a cross talk between IGF1R and ERα at different levels and data suggest enhanced IGF1R signaling as a causative mechanism of tamoxifen (TAM) resistance. We tested whether functional germline variations in the IGF pathway are associated with clinical outcome in ER-positive primary invasive breast cancer patients, who were treated with surgery and adjuvant TAM. Tissue samples of 222 patients with ER+ primary invasive breast cancer, who had undergone surgery at Charing Cross Hospital, London, UK between 1981 and 2003, were analyzed. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue samples and six functional IGF1 pathway polymorphisms were analyzed using direct DNA sequencing and PCR-restriction fragment length polymorphism. In multivariable analysis, patients with primary invasive breast cancer carrying IGF1R_rs2016347 G allele had a significantly increased risk of early tumor progression (hazard ratio (HR) 2.01; adjusted P=0.004) and death (HR 1.84; adjusted P=0.023) compared with patients carrying G/T or T/T, independent of established clinicopathological determinants. This association remained significant after adjusting for multiple testing. In addition, we were able to demonstrate that IRS1_rs1801123 and IGFBP3_rs2854744 were significantly associated with lymph node involvement and tumor size, respectively. We provide the first evidence for IGF1R_rs2016347 as an independent prognostic marker for ER+ breast cancer patients treated with TAM and support a rational for combined treatment strategies.

New perspective for an old antidiabetic drug: metformin as anticancer agent

Metformin, an inexpensive, well-tolerated oral agent that is commonly used in the first-line treatment for type 2 diabetes, has become the focus of intense research as a potential anticancer agent. This research reflects a convergence of epidemiologic, clinical, and preclinical evidence, suggesting that metformin may lower cancer risk in diabetics and improve outcomes of many common cancers. Notably, metformin mediates an approximately 30 % reduction in the lifetime risk of cancer in diabetic patients. There is growing recognition that metformin may act (1) directly on cancer cells, primarily by impacting mitochondrial respiration leading to the activation of the AMP-activated protein kinase (AMPK), which controls energy homeostasis in cells, but also through other mechanisms or (2) indirectly on the host metabolism, largely through AMPK-mediated reduction in hepatic gluconeogenesis, leading to reduced circulating insulin levels and decreased insulin/IGF-1 receptor-mediated activation of the PI3K pathway. Support for this comes from the observation that metformin inhibits cancer cell growth in vitro and delays the onset of tobacco carcinogen-induced lung cancer in mice and that metformin and its analog phenformin delay spontaneous tumor development cancer-prone transgenic mice. The potential for both direct antitumor effects and indirect host-mediated effects has sparked enormous interest, but has led to added challenges in translating preclinical findings to the clinical setting. Nonetheless, the accumulation of evidence has been sufficient to justify initiation of clinical trials of metformin as an anticancer agent in the clinical setting, including a large-scale adjuvant study in breast cancer, with additional studies planned.

Meta-analysis of the association of glutathione S-transferase T1 null/presence gene polymorphism with the risk of gastric carcinoma

A possible association of glutathione S-transferase T1 (GSTT1) null/presence gene polymorphism and an increased risk of developing gastric carcinoma is still unclear and hotly debated. This investigation was performed to assess the association of the GSTT1 null/presence gene polymorphism with the risk of gastric carcinoma via a meta-analysis to increase sample size and statistical significance. PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) were searched on March 1, 2013, association reports were identified, and eligible studies were recruited and synthesized. Fifty-two reports were found to be suitable for this meta-analysis for the association of the GSTT1 null genotype with gastric carcinoma risk. The results showed that there was a significantly increased gastric carcinoma risk when the GSTT1 null genotype was present in the overall population (OR 1.21, 95 % CI 1.11-1.32, P < 0.0001), Caucasians (OR 1.25, 95 % CI 1.05-1.48, P = 0.01), East-Asians (OR 1.18, 95 % CI 1.06-1.31, P = 0.003), and Chinese (OR 1.24, 95 % CI 1.07-1.44, P = 0.005). However, no statistically relevant association could be established for the Indian ethnic group (OR 1.33, 95 % CI 0.94-1.90, P = 0.11). In conclusion, the GSTT1 null genotype is associated with an increased gastric carcinoma risk in the overall population, Caucasians, East-Asians, and Chinese.

Targeted re-sequencing identified rs3106189 at the 5' UTR of TAPBP and rs1052918 at the 3' UTR of TCF3 to be associated with the overall survival of colorectal cancer patients

Recent studies have demonstrated the power of deep re-sequencing of the whole genome or exome in understanding cancer genomes. However, targeted capture of selected genomic whole gene-body regions, rather than the whole exome, have several advantages: 1) the genes can be selected based on biology or a hypothesis; 2) mutations in promoter and intronic regions, which have important regulatory roles, can be investigated; and 3) less expensive than whole genome or whole exome sequencing. Therefore, we designed custom high-density oligonucleotide microarrays (NimbleGen Inc.) to capture approximately 1.7 Mb target regions comprising the genomic regions of 28 genes related to colorectal cancer including genes belonging to the WNT signaling pathway, as well as important transcription factors or colon-specific genes that are over expressed in colorectal cancer (CRC). The 1.7 Mb targeted regions were sequenced with a coverage ranged from 32× to 45× for the 28 genes. We identified a total of 2342 sequence variations in the CRC and corresponding adjacent normal tissues. Among them, 738 were novel sequence variations based on comparisons with the SNP database (dbSNP135). We validated 56 of 66 SNPs in a separate cohort of 30 CRC tissues using Sequenom MassARRAY iPLEX Platform, suggesting a validation rate of at least 85% (56/66). We found 15 missense mutations among the exonic variations, 21 synonymous SNPs that were predicted to change the exonic splicing motifs, 31 UTR SNPs that were predicted to occur at the transcription factor binding sites, 20 intronic SNPs located near the splicing sites, 43 SNPs in conserved transcription factor binding sites and 32 in CpG islands. Finally, we determined that rs3106189, localized to the 5′ UTR of antigen presenting tapasin binding protein (TAPBP), and rs1052918, localized to the 3′ UTR of transcription factor 3 (TCF3), were associated with overall survival of CRC patients.

Prognostic assessment of apoptotic gene polymorphisms in non-small cell lung cancer in Chinese

Apoptosis plays a key role in inhibiting tumor growth, progression and resistance to anti-tumor therapy. We hypothesized that genetic variants in apoptotic genes may affect the prognosis of lung cancer. To test this hypothesis, we selected 38 potentially functional single nucleotide polymorphisms (SNPs) from 12 genes (BAX, BCL2, BID, CASP3, CASP6, CASP7, CASP8, CASP9, CASP10, FAS, FASLG and MCL1) involved in apoptosis to assess their prognostic significance in lung cancer in a Chinese case cohort with 568 non-small cell lung cancer (NSCLC) patients. Thirty-five SNPs passing quality control underwent association analyses, 11 of which were shown to be significantly associated with NSCLC survival (P < 0.05). After Cox stepwise regression analyses, 3 SNPs were independently associated with the outcome of NSCLC (BID rs8190315: P = 0.003; CASP9 rs4645981: P = 0.007 and FAS rs1800682: P = 0.016). A favorable survival of NSCLC was significantly associated with the genotypes of BID rs8190315 AG/GG (adjusted HR = 0.65, 95% CI: 0.49-0.88), CASP9 rs4645981 AA (HR = 0.22, 95% CI: 0.07-0.69) and FAS rs1800682 GG (adjusted HR = 0.67, 95% CI: 0.46-0.97). Time-dependent receptor operation curve (ROC) analysis revealed that the area under curve (AUC) at year 5 was significantly increased from 0.762 to 0.819 after adding the risk score of these 3 SNPs to the clinical risk score. The remaining 32 SNPs were not significantly associated with NSCLC prognosis after adjustment for these 3 SNPs. These findings indicate that BID rs8190315, CASP9 rs4645981 and FAS rs1800682 polymorphisms in the apoptotic pathway may be involved in the prognosis of NSCLC in the Chinese population.

Plasma Vitamin D Levels And Vitamin D Receptor Polymorphisms Are Associated with Survival of Non-small Cell Lung Cancer

OBJECTIVE

Vitamin D and its receptor (VDR) involve in multiple cellular processes and play an important role in the initiation and progression of malignancy. Thus we hypothesized that plasma vitamin D levels and single nucleotide polymorphisms (SNPs) in VDR may be of prognostic significance in non-small cell lung cancer (NSCLC).

METHODS

We examined plasma 25-hydroxyvitamin D [25(OH)D] levels in 87 patients diagnosed with NSCLC using enzyme-linked immunosorbent assay (ELISA) and genotyped seven potentially functional SNPs in VDR in 568 NSCLC patients on Illumina Golden Gate platform.

RESULTS

Patients with higher plasma 25(OH)D levels had worse survival than patients with lower ones (P for trend = 0.048). The SNPs of rs1544410 and rs739837 were independently associated with NSCLC survival (adjusted HR = 1.61, 95% CIs = 1.06-2.45 for rs739837 AA vs AC/CC and adjusted HR = 1.51, 95% CIs = 1.06-2.16 for rs1544410 AG/AA vs GG). A joint effect was observed between rs1544410 and rs739837 and the risk of death elevated as the number of unfavourable genotypes patients carried increased (P for trend = 0.003). There were no significant associations between VDR polymorphisms and plasma 25(OH)D levels.

CONCLUSION

Our findings indicate that plasma 25(OH)D levels and genetic variants of VDR may serve as prognostic markers for NSCLC in this Chinese population.

Association between single nucleotide polymorphism of PD-L1 gene and non-small cell lung cancer susceptibility in a Chinese population

AIM

To evaluate the correlation between a polymorphism of PD-L1 gene and the susceptibility of non-small cell lung cancer (NSCLC) in a Chinese population.

METHODS

A total of 293 Chinese patients with NSCLC and 293 age and sex matched controls of the same ethnic origin were enrolled in this study. A/C polymorphism at position 8923 in intron 4 of PD-L1 gene was typed using the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). The interactions between A/C genotype, allele frequency and NSCLC susceptibility were analyzed.

RESULTS

The A/C genotype frequencies were significantly different between NSCLC patients and controls. The AC and CC frequencies were higher in NSCLC patients than in controls (16.4 vs 8.9%, 1.0 vs 0.3%, respectively). The C-allele frequency was higher in NSCLC patients than in controls (9.2 vs 4.8%). Significant differences in the A and C allele frequencies were noted between the two groups (χ(2) = 8.864, P = 0.003). More risk of NSCLC was found in individuals carrying the C allele than in those carrying the A allele (OR = 2.203; 95% CI 1.262-3.242). In both light smokers (≤20 pack-years) and heavy smokers (>20 pack-years), individuals carrying the C-allele had more risk of NSCLC than those carrying the A-allele (light smokers OR = 1.847, 95% CI 1.001-3.409; heavy smokers OR = 3.252, 95% CI 1.196-8.845, respectively).

CONCLUSION

An A/C polymorphism at position 8923 in the PD-L1 gene is associated with NSCLC susceptibility. The PD-L1 polymorphism plays a role in NSCLC, especially in patients with the C-allele.

Igf-I regulates pheochromocytoma cell proliferation and survival in vitro and in vivo

IGFs are involved in malignant transformation and growth of several tissues, including the adrenal medulla. The present study was designed to evaluate the impact of IGF-I on pheochromocytoma development. We used a murine pheochromocytoma (MPC) cell line (MPC4/30) and an animal model with a reduction of 75% in circulating IGF-I levels [liver-IGF-I-deficient (LID) mice] to perform studies in vitro and in vivo. We found that, in culture, IGF-I stimulation increases proliferation, migration, and anchorage-independent growth, whereas it inhibits apoptosis of MPC cells. When injected to control and to LID mice, MPC cells grow and form tumors with features of pheochromocytoma. Six weeks after cell inoculation, all control mice developed sc tumors. In contrast, in 73% of LID mice, tumor development was delayed to 7-12 wk, and the remaining 27% did not develop tumors up to 12 wk after inoculation. LID mice harboring MPC cells and treated with recombinant human IGF-I (LID+) developed tumors as controls. Tumors developed in control, LID, and LID+ mice had similar histology and were similarly positive for IGF-I receptor expression. The apoptotic index was higher in tumors from LID mice compared with those from control mice, whereas vascular density was decreased. In summary, our work demonstrates that IGF-I has a critical role in maintaining tumor phenotype and survival of already transformed pheochromocytoma cells and is required for the initial establishment of these tumors, providing encouragement to carry on research studies to address the IGF-I/IGF-I receptor system as a target of therapeutic strategies for pheochromocytoma treatment in the future.

Genetic polymorphism of IGF-I predicts recurrence in patients with gastric cancer who have undergone curative gastrectomy

BACKGROUND

To our knowledge, no reports have evaluated the effects of genetic polymorphisms of insulin-like growth factor-I (IGF-I) on clinical outcomes of gastric cancer patients.

METHODS

We retrospectively analyzed the impact of IGF-I polymorphisms on recurrence-free survival (RFS) in 430 patients with gastric cancer who underwent curative gastrectomy between 2001 and 2005 in our institution.

RESULTS

Among the 430 gastric cancer patients, 345 were pathological stage I or II, while 85 were stage III or IV. The median 5-year RFS rate was 85.3% (95% confidence interval [CI] 81.4-88.5). In a multivariate Cox model (adjusted for age, gender, histology, pathological stage, adjuvant chemotherapy, and history of diabetes), two IGF-I polymorphisms, rs1520220 and rs2195239, were significantly associated with RFS (hazard ratio [HR] 0.60, 95% CI 0.40-0.91; and HR 0.60, 95% CI 0.41-0.89, respectively, in a per-allele model). When stratified by stage (I-II versus III-IV), rs1520220 in particular was associated with RFS in patients with stage III-IV disease, with a P-value for interaction of 0.01.

CONCLUSIONS

Our findings indicate that genetic polymorphisms of IGF-I may have a substantial effect on recurrence for gastric cancer patients who have undergone curative gastrectomy. This information may help identify population subgroups that could benefit from IGF-I-targeting agents.

Potentially functional polymorphisms in DNA repair genes and non-small-cell lung cancer survival: a pathway-based analysis

To assess systematically whether potentially functional polymorphisms in DNA repair genes influence the clinical behavior of non-small-cell lung cancer (NSCLC), we examined the impact of a comprehensive panel of 218 signal nucleotide polymorphisms (SNP) in 50 candidate DNA repair genes on overall survival of NSCLC in a case-cohort of 568 lung cancer patients. SNPs associated with lung cancer prognosis primarily mapped to 14 genes in different repair pathways, and 6 SNPs were remained in the final model after multivariate stepwise Cox regression analysis: ATM rs189037; MRE11A rs11020802; ERCC2 rs1799793; MBD4 rs140693; XRCC1 rs25487, and PMS1 rs5742933. In the combined analysis of these 6 SNPs, an increasing number of unfavorable loci was associated with a poorer prognosis (P for trend: <0.0001) and patients having 2-4 unfavorable loci had a 1.99-fold elevated risk of death 95% confidence interval (CI) = 1.58-2.50, compared with those carrying 0-1 unfavorable loci, and this elevated risk was more evident among stages I-II patients (hazard ratio = 3.04, 95% CI = 1.86-4.98, P for heterogeneity: 0.07). Furthermore, a significant effect of SNPs in nucleotide excision repair pathway on lung cancer survival was observed among 185 stages III-IV patients treated with platinum-based chemotherapy without surgical operation: XPC rs2228000 (Ala499Val; P = 0.002) and ERCC1 rs11615 (Asn118Asn; P = 0.012). Our data indicate that potentially functional polymorphisms in DNA repair genes may serve as candidate prognostic markers of clinical outcome of NSCLC.

Visceral adiposity, insulin resistance and cancer risk

BACKGROUND

There is a well established link between obesity and cancer. Emerging research is characterising this relationship further and delineating the specific role of excess visceral adiposity, as opposed to simple obesity, in promoting tumorigenesis. This review summarises the evidence from an epidemiological and pathophysiological perspective.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Numerous epidemiological studies consistently identify increased risk of developing carcinoma in the obese. Adipose tissue, particularly viscerally located fat, is metabolically active and exerts systemic endocrine effects. Putative pathophysiological mechanisms linking obesity and carcinogenesis include the paracrine effects of adipose tissue and systemic alterations associated with obesity. Systemic changes in the obese state include chronic inflammation and alterations in adipokines and sex steroids. Insulin and the insulin-like growth factor axis influence tumorigenesis and also have a complex relationship with adiposity. There is evidence to suggest that insulin and the IGF axis play an important role in mediating obesity associated malignancy.

CONCLUSIONS

There is much evidence to support a role for obesity in cancer progression, however further research is warranted to determine the specific effect of excess visceral adipose tissue on tumorigenesis. Investigation of the potential mechanisms underpinning the association, including the role of insulin and the IGF axis, will improve understanding of the obesity and cancer link and may uncover targets for intervention.

IGF gene polymorphisms and breast cancer in African-American and Hispanic women

Previous studies from our group and others have shown that increased circulatory levels of the ligand insulin-like growth factor 1 (IGF-1) and decreased levels of the predominant IGF-1 binding protein 3 (IGFBP-3) are associated with an increased incidence of breast cancer and poor outcome. Some studies suggest that, in addition to the influence of environmental factors on the levels of IGF-1 and IGFBP-3, alterations in their gene polymorphisms may play a significant role in the risk of cancer. In this study, we investigated the association between gene polymorphisms along the IGF axis and breast cancer, including the IGF-1 (CA) dinucleotide repeat, IGFBP-3 A-202C single nucleotide polymorphism, and the 2-bp deletion and (AGG)n repeat polymorphisms in the IGF type 1 receptor (IGF-IR). A total of 654 subjects, including both African-American and Hispanic/Latino subjects, were screened for various gene polymorphisms. IGF gene polymorphism genotyping was performed by PCR-GeneScan and PCR-RFLP methods. Our results demonstrated a significant association between the non-19/non-19 IGF-1 (CA)n polymorphism and breast cancer (OR = 1.75; 95% CI = 1.07-2.88; P = 0.027). Furthermore, absence of the wild-type-19 allele and alleles <(CA)19 were strongly associated with breast cancer (OR = 1.82; 95% CI = 1.20-2.77; P = 0.005 and OR = 1.70; 95% CI = 1.19-2.43; P = 0.003, respectively). The association of the non-19/non-19 polymorphism with breast cancer was also more significant in premenopausal women (P = 0.04). We did not find any significant association of the IGFBP-3 polymorphism with breast cancer. In the case of IGF-1R polymorphisms, the only significant trend was in the (AGG)5 allele; however, the frequency of this allele was very rare. In summary, our study demonstrated a significant association of IGF-1 polymorphisms and breast cancer. Future studies are necessary to understand the mechanistic value of these polymorphisms in breast cancer risk.

Prognostic significance of survivin polymorphisms on non-small cell lung cancer survival

INTRODUCTION

Survivin is an apoptotic inhibitor, involves in regulation of apoptosis and cell cycle progression, and its polymorphisms may influence the development and progression of cancer. This study evaluated the impact of the survivin gene polymorphisms on survival of non-small cell lung cancer (NSCLC) patients.

METHODS

In this case-cohort follow-up study, a total of 568 NSCLC patients were investigated and 12 single nucleotide polymorphisms in survivin gene were genotyped by using the Illumina GoldenGate platform.

RESULTS

During the maximum of 72 months of follow-up, 314 (55.11%) deaths were observed. After adjusting for age, gender, smoking status, histology, stage, surgical operation, and chemotherapy or radiotherapy status, Cox hazard proportional model suggested that four single nucleotide polymorphisms had statistically significant impacts on NSCLC survival (rs3764383, AG/GG versus AA, hazard ratio [HR] = 0.78, 95% confidence interval [CI]: 0.62-0.99; rs8073069, GG versus CG/CC, HR = 1.76, 95% CI: 1.16-2.67; rs4789551, GG versus AG/AA, HR = 2.04, 95% CI: 1.08-3.86; rs1042489, GG versus AG/AA, HR = 1.37, 95% CI: 1.03-1.83). Further combined analysis showed that the high risk group (3-4 unfavorable loci) presented a 1.84-fold (95% CI: 1.22-2.77) increased risk compared with low risk group (0-2 unfavorable loci). Among 185 stage III to IV patients who received only chemotherapy, only the potentially functional rs8073069 still had a significantly increased risk on the prognosis of NSCLC (GG versus CG/CC, HR = 2.06, 95% CI: 1.10-3.87).

CONCLUSIONS

Our results suggest that polymorphisms in survivin may be a genetic modifier for NSCLC prognosis in this Chinese population.

Potentially functional polymorphisms in cell cycle genes and the survival of non-small cell lung cancer in a Chinese population

The cell cycle governs the proliferation and growth of cells and is strictly controlled by some regulators including cyclins, CDKs and CKIs. Germ-line and somatic mutations in cell cycle genes were frequently observed in a subset of cancers including non-small cell lung cancer (NSCLC). In this study, we hypothesized that potentially functional single nucleotide polymorphisms (SNPs) in cell cycle genes may contribute to the prognosis of NSCLC in China. 54 potentially functional polymorphisms in key cell cycle genes (CDK1, CDK2, CDK4, CDK6, CDK7, CCND1, CCND2, CCND3, CCNE1, CCNA1, CCNA2, CCNB1, CCNH, p15, p16, p18, p19, p21, p27, Cdc25A and Cdc25B) were genotyped by using Illumina SNP genotyping platform to evaluate their associations with survival of NSCLC in a clinical cohort of 568 patients. We found that p18 rs3176447 variant genotypes were significantly associated with the decreased risk of death of NSCLC patients (adjusted HR=0.74, 95% CI=0.57-0.97 in an additive model; adjusted HR=0.76, 95% CI=0.55-0.97 in a dominant model); however, p21 rs2395655 variant genotypes were significantly associated with the increased risk of death (adjusted HR=1.21, 95% CI=1.02-1.42 in an additive model; adjusted HR=1.38, 95% CI=1.07-1.78 in a recessive model). Furthermore, the combined effect of unfavorable genotypes for these two SNPs was more prominent in patients with squamous cell carcinoma, late stage and without chemo- or radio-therapy. Although the exact biological function remains to be explored, our findings suggest possible association of polymorphisms of p18 and p21 with the prognosis of NSCLC in a Chinese population. Further large and functional studies are needed to confirm our findings.

Germline polymorphisms in genes involved in the IGF1 pathway predict efficacy of cetuximab in wild-type KRAS mCRC patients

PURPOSE

The insulin-like growth factor 1 (IGF1) signaling pathway is an important growth-regulatory pathway, which plays a crucial role in colorectal cancer (CRC) proliferation, differentiation, migration, angiogenesis, and apoptosis. Previous studies showed that hyperactivation of the IGF1 receptor (IGF1R) may result in resistance to anti-epidermal growth factor receptor-targeted treatment. We tested whether germline variations within the IGF1 pathway are associated with clinical outcome in wild-type (wt) KRAS drug-refractory metastatic CRC (mCRC) patients who were treated with cetuximab monotherapy (IMC-0144).

EXPERIMENTAL DESIGN

Formalin-fixed, paraffin-embedded (FFPE) tissue samples of 130 drug-refractory mCRC patients enrolled in IMC-0144, a phase II clinical trial of cetuximab monotherapy, were analyzed. gDNA was extracted from dissected FFPE tumor tissue, and KRAS mutation status and six potentially functional IGF1 and IGF1R polymorphisms were analyzed using direct DNA sequencing or PCR-RFLP. Tumor response analysis was based on recursive partitioning, and survival analyses were based on univariate and multivariate hazard regression models.

RESULTS

In univariate and multivariate analyses, five IGF pathway single-nucleotide polymorphisms were significantly associated with progression-free survival (PFS) and/or overall survival (OS). In multivariate combined risk allele analysis, the additive model for PFS and OS was significantly associated with the number of risk alleles in wt KRAS patients (P = 0.001 and P = 0.02, respectively). In addition, wt KRAS patients harboring IGF1 rs2946834 A/A genotype had a 50% objective response rate compared with 0% for A/G genotype.

CONCLUSIONS

These results indicate that IGF1 pathway polymorphisms are potential predictive/prognostic molecular markers for cetuximab efficacy in wt KRAS mCRC patients. Prospective biomarker-embedded clinical trials are warranted to validate our findings. Clin Cancer Res; 16(22); 5591-602. ©2010 AACR.

Insulin-like growth factors and insulin control a multifunctional signalling network of significant importance in cancer

Insulin-like growth factor (IGF) and insulin (INS) proteins regulate key cellular functions through a complex interacting multi-component molecular network, known as the IGF/INS axis. We describe how dynamic and multilayer interactions give rise to the multifunctional role of the IGF/INS axis. Furthermore, we summarise the importance of the regulatory IGF/INS network in cancer, and discuss the possibilities and limitations of therapies targeting the IGF/INS axis with reference to ongoing clinical trials concerning the blockage of IGF1R in several types of cancer.