Circulating insulin-like growth factors and risks of overall, aggressive and early-onset prostate cancer: a collaborative analysis of 20 prospective studies and Mendelian randomization analysis

BACKGROUND

Previous studies had limited power to assess the associations of circulating insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) with clinically relevant prostate cancer as a primary endpoint, and the association of genetically predicted IGF-I with aggressive prostate cancer is not known. We aimed to investigate the associations of IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3 concentrations with overall, aggressive and early-onset prostate cancer.

METHODS

Prospective analysis of biomarkers using the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group dataset (up to 20 studies, 17 009 prostate cancer cases, including 2332 aggressive cases). Odds ratios (OR) and 95% confidence intervals (CI) for prostate cancer were estimated using conditional logistic regression. For IGF-I, two-sample Mendelian randomization (MR) analysis was undertaken using instruments identified using UK Biobank (158 444 men) and outcome data from PRACTICAL (up to 85 554 cases, including 15 167 aggressive cases). Additionally, we used colocalization to rule out confounding by linkage disequilibrium.

RESULTS

In observational analyses, IGF-I was positively associated with risks of overall (OR per 1 SD = 1.09: 95% CI 1.07, 1.11), aggressive (1.09: 1.03, 1.16) and possibly early-onset disease (1.11: 1.00, 1.24); associations were similar in MR analyses (OR per 1 SD = 1.07: 1.00, 1.15; 1.10: 1.01, 1.20; and 1.13; 0.98, 1.30, respectively). Colocalization also indicated a shared signal for IGF-I and prostate cancer (PP4: 99%). Men with higher IGF-II (1.06: 1.02, 1.11) and IGFBP-3 (1.08: 1.04, 1.11) had higher risks of overall prostate cancer, whereas higher IGFBP-1 was associated with a lower risk (0.95: 0.91, 0.99); these associations were attenuated following adjustment for IGF-I.

CONCLUSIONS

These findings support the role of IGF-I in the development of prostate cancer, including for aggressive disease.

Circulating free testosterone and risk of aggressive prostate cancer: Prospective and Mendelian randomisation analyses in international consortia

Previous studies had limited power to assess the associations of testosterone with aggressive disease as a primary endpoint. Further, the association of genetically predicted testosterone with aggressive disease is not known. We investigated the associations of calculated free and measured total testosterone and sex hormone-binding globulin (SHBG) with aggressive, overall and early-onset prostate cancer. In blood-based analyses, odds ratios (OR) and 95% confidence intervals (CI) for prostate cancer were estimated using conditional logistic regression from prospective analysis of biomarker concentrations in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group (up to 25 studies, 14 944 cases and 36 752 controls, including 1870 aggressive prostate cancers). In Mendelian randomisation (MR) analyses, using instruments identified using UK Biobank (up to 194 453 men) and outcome data from PRACTICAL (up to 79 148 cases and 61 106 controls, including 15 167 aggressive cancers), ORs were estimated using the inverse-variance weighted method. Free testosterone was associated with aggressive disease in MR analyses (OR per 1 SD = 1.23, 95% CI = 1.08-1.40). In blood-based analyses there was no association with aggressive disease overall, but there was heterogeneity by age at blood collection (OR for men aged <60 years 1.14, CI = 1.02-1.28; Phet  = .0003: inverse association for older ages). Associations for free testosterone were positive for overall prostate cancer (MR: 1.20, 1.08-1.34; blood-based: 1.03, 1.01-1.05) and early-onset prostate cancer (MR: 1.37, 1.09-1.73; blood-based: 1.08, 0.98-1.19). SHBG and total testosterone were inversely associated with overall prostate cancer in blood-based analyses, with null associations in MR analysis. Our results support free testosterone, rather than total testosterone, in the development of prostate cancer, including aggressive subgroups.

Dairy products and the risk of developing prostate cancer: A large-scale cohort study (JACC Study) in Japan

Dairy products have been indicated as a risk factor for prostate cancer. However, only a few epidemiological studies have reported dairy products as being a risk factor for prostate cancer in Japan, reporting contradictory results. We therefore investigated the association between the intake of dairy products and the occurrence of prostate cancer through a large‐scale cohort study. The Japan Collaborative Cohort study analyzed approximately 110,000 residents from various Japanese districts who participated in our questionnaire survey during 1988–1990. The subjects of the present study were 26,464 men (age range: 40–79 years) from 24 districts wherein cancer incidence was reported. Their clinical course was followed up until 2009. Hazard ratios (HRs) were calculated using Cox's proportional hazards model, adjusted for age, survey area, family history of prostate cancer, body mass index, and total energy intake. For diet, we calculated the HRs associated with intermediate and high consumption of dairy products and compared them with those associated with low consumption. There were 412 cases of prostate cancer in the survey population. As dairy products, milk, yogurt, cheese, and butter were evaluated. Among them, milk consumption was associated with a significant risk (HR = 1.37, p = 0.009) and a dose‐dependent response (p for trend = 0.009) adjusted for age and family history of prostate cancer, stratified by area. Milk and yogurt consumption showed a significantly positive risk and a dose–response relationship adjusted for age, family history of prostate cancer, body mass index, and total energy intake, stratified by area. In summary, a high intake of dairy products such as milk increased the risk of developing prostate cancer in Japanese men.

Efficacy and safety of abiraterone acetate plus prednisolone in patients with early metastatic castration-resistant prostate cancer who failed first-line androgen-deprivation therapy: a single-arm, phase 4 study

Aim

The aim was to evaluate the efficacy and safety of abiraterone acetate plus prednisolone in patients with chemotherapy-naïve early metastatic castration-resistant prostate cancer who failed first-line androgen deprivation therapy.

Methods

Patients with early metastatic castration-resistant prostate cancer with confirmed prostate-specific antigen progression within 1-year or prostate-specific antigen progression without having normal prostate-specific antigen level (<4.0 ng/mL) during first-line androgen deprivation therapy were enrolled and administered abiraterone acetate (1000 mg) plus prednisolone (10 mg). A minimum of 48 patients were required according to Simon’s minimax design. The primary endpoint was prostate-specific antigen response rate (≥50% prostate-specific antigen decline by 12 weeks), secondary endpoints included prostate-specific antigen progression-free survival and overall survival. Safety parameters were also assessed.

Results

For efficacy, 49/50 patients were evaluable. Median age was 73 (range: 55–86) years. The median duration of initial androgen deprivation therapy was 32.4 (range: 13.4–84.1) weeks and 48 patients experienced prostate-specific antigen progression within 1-year after initiation of androgen deprivation therapy. prostate-specific antigen response rate was 55.1% (95% confidence interval: 40.2%–69.3%), median prostate-specific antigen–progression-free survival was 24.1 weeks, and median overall survival was 102.9 weeks (95% confidence interval: 64.86 not estimable [NE]). Most common adverse event was nasopharyngitis (15/50 patients, 30.0%). The most common ≥grade 3 adverse event was alanine aminotransferase increased (6/50 patients, 12.0%).

Conclusions

Abiraterone acetate plus prednisolone demonstrated a high prostate-specific antigen response rate of 55.1%, suggesting tumor growth still depends on androgen synthesis in patients with early metastatic castration-resistant prostate cancer. However, prostate-specific antigen–progression-free survival was shorter than that reported in previous studies. Considering the benefit–risk profile, abiraterone acetate plus prednisolone would be a beneficial treatment option for patients with chemotherapy-naive metastatic prostate cancer who show early castration resistance.

Remitting seronegative symmetrical synovitis with pitting edema syndrome in maintenance hemodialysis

INTRODUCTION

The remitting seronegative symmetrical synovitis with pitting edema syndrome primarily occurs in elderly individuals to represent symptoms of edema, pain, and joint swelling. It could be misdiagnosed in elderly maintenance hemodialysis patients, as hemodialysis patients often present with pain and joint swelling induced by hypervolemia, inflammation, amyloidosis, and/or chronic kidney disease. Here, we describe a maintenance hemodialysis patient with remitting seronegative symmetrical synovitis with pitting edema syndrome.

CASE PRESENTATION

A 71-year-old man on maintenance hemodialysis who complained of continuous pain and swelling of joints was diagnosed with remitting seronegative symmetrical synovitis with pitting edema syndrome on his clinical findings that revealed tenosynovitis at the joint without joint erosions and no elevation of anti-cyclic citrullinated peptide antibody and rheumatoid factor. After administration of prednisolone, systemic edema, and pain improved in 2 days.

CONCLUSION

Remitting seronegative symmetrical synovitis with pitting edema syndrome should be considered as a differential diagnosis in hemodialysis patients with edema and/or arthralgia.

The associations of anthropometric, behavioural and sociodemographic factors with circulating concentrations of IGF-I, IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3 in a pooled analysis of 16,024 men from 22 studies

Insulin-like growth factors (IGFs) and insulin-like growth factor binding proteins (IGFBPs) have been implicated in the aetiology of several cancers. To better understand whether anthropometric, behavioural and sociodemographic factors may play a role in cancer risk via IGF signalling, we examined the cross-sectional associations of these exposures with circulating concentrations of IGFs (IGF-I and IGF-II) and IGFBPs (IGFBP-1, IGFBP-2 and IGFBP-3). The Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group dataset includes individual participant data from 16,024 male controls (i.e. without prostate cancer) aged 22-89 years from 22 prospective studies. Geometric means of protein concentrations were estimated using analysis of variance, adjusted for relevant covariates. Older age was associated with higher concentrations of IGFBP-1 and IGFBP-2 and lower concentrations of IGF-I, IGF-II and IGFBP-3. Higher body mass index was associated with lower concentrations of IGFBP-1 and IGFBP-2. Taller height was associated with higher concentrations of IGF-I and IGFBP-3 and lower concentrations of IGFBP-1. Smokers had higher concentrations of IGFBP-1 and IGFBP-2 and lower concentrations of IGFBP-3 than nonsmokers. Higher alcohol consumption was associated with higher concentrations of IGF-II and lower concentrations of IGF-I and IGFBP-2. African Americans had lower concentrations of IGF-II, IGFBP-1, IGFBP-2 and IGFBP-3 and Hispanics had lower IGF-I, IGF-II and IGFBP-3 than non-Hispanic whites. These findings indicate that a range of anthropometric, behavioural and sociodemographic factors are associated with circulating concentrations of IGFs and IGFBPs in men, which will lead to a greater understanding of the mechanisms through which these factors influence cancer risk.

RBM10-TFE3 renal cell carcinoma characterised by paracentric inversion with consistent closely split signals in break-apart fluorescence in-situ hybridisation: study of 10 cases and a literature review

AIMS

Xp11 rearrangement in renal cell carcinoma (RCC) typically involves gene fusion to the gene encoding transcription factor E3 (TFE3), a member of the microphthalmia-associated transcription factor family on chromosome Xp11.2. Dual-colour break-apart fluorescence in-situ hybridisation (FISH) is recommended to confirm histological diagnoses. Recently, RNA-binding motif protein 10 (RBM10), encoded by a gene on chromosome Xp11.3, was identified as a chimeric partner of TFE3; thus, RBM10-TFE3 fusion results from paracentric inversion. RBM10-TFE3 RCC may yield a false-negative result in FISH analysis of TFE3 expression. The aim of the present study was to investigate the clinicopathological features of RBM10-TFE3 RCC.

METHODS AND RESULTS

Ten patients with RBM10-TFE3 RCC aged 31-71 years were investigated. Histological analysis, immunostaining, dual-colour break-apart FISH for TFE3, reverse transcription polymerase chain reaction and sequencing analysis were performed. No patient had a history of exposure to chemotherapy. Two of these patients died of RCC, and three were alive but developed metastases. Microscopically, the tumours were composed of a mixed architecture of tubulocystic and papillary patterns with scattered psammoma bodies. The tumours showed strong nuclear immunoreactivity for TFE3. FISH showed consistent closely spaced split signals in the RCCs of four patients, and polysomic signals with occasional closely spaced split signals in the RCCs of six patients. Of the latter six patients, five had renal failure, and four developed tumours in kidneys subjected to haemodialysis.

CONCLUSIONS

The present study suggests that the carcinogenesis of RBM10-TFE3 RCC in some, but not all, patients may be associated with chronic kidney disease. The aggressive nature of RBM10-TFE3 RCC should be considered, as five patients experienced metastases.

Circulating isoflavone and lignan concentrations and prostate cancer risk: a meta-analysis of individual participant data from seven prospective studies including 2,828 cases and 5,593 controls

Phytoestrogens may influence prostate cancer development. This study aimed to examine the association between prediagnostic circulating concentrations of isoflavones (genistein, daidzein, equol) and lignans (enterolactone and enterodiol) and the risk of prostate cancer. Individual participant data were available from seven prospective studies (two studies from Japan with 241 cases and 503 controls and five studies from Europe with 2,828 cases and 5,593 controls). Because of the large difference in circulating isoflavone concentrations between Japan and Europe, analyses of the associations of isoflavone concentrations and prostate cancer risk were evaluated separately. Prostate cancer risk by study-specific fourths of circulating concentrations of each phytoestrogen was estimated using multivariable-adjusted conditional logistic regression. In men from Japan, those with high compared to low circulating equol concentrations had a lower risk of prostate cancer (multivariable-adjusted OR for upper quartile [Q4] vs. Q1 = 0.61, 95% confidence interval [CI] = 0.39-0.97), although there was no significant trend (OR per 75 percentile increase = 0.69, 95 CI = 0.46-1.05, ptrend = 0.085); Genistein and daidzein concentrations were not significantly associated with risk (ORs for Q4 vs. Q1 = 0.70, 0.45-1.10 and 0.71, 0.45-1.12, respectively). In men from Europe, circulating concentrations of genistein, daidzein and equol were not associated with risk. Circulating lignan concentrations were not associated with the risk of prostate cancer, overall or by disease aggressiveness or time to diagnosis. There was no strong evidence that prediagnostic circulating concentrations of isoflavones or lignans are associated with prostate cancer risk, although further research is warranted in populations where isoflavone intakes are high.

Low Free Testosterone and Prostate Cancer Risk: A Collaborative Analysis of 20 Prospective Studies

BACKGROUND

Experimental and clinical evidence implicates testosterone in the aetiology of prostate cancer. Variation across the normal range of circulating free testosterone concentrations may not lead to changes in prostate biology, unless circulating concentrations are low. This may also apply to prostate cancer risk, but this has not been investigated in an epidemiological setting.

OBJECTIVE

To examine whether men with low concentrations of circulating free testosterone have a reduced risk of prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Analysis of individual participant data from 20 prospective studies including 6933 prostate cancer cases, diagnosed on average 6.8 yr after blood collection, and 12 088 controls in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Odds ratios (ORs) of incident overall prostate cancer and subtypes by stage and grade, using conditional logistic regression, based on study-specific tenths of calculated free testosterone concentration.

RESULTS AND LIMITATIONS

Men in the lowest tenth of free testosterone concentration had a lower risk of overall prostate cancer (OR=0.77, 95% confidence interval [CI] 0.69-0.86; p<0.001) compared with men with higher concentrations (2nd-10th tenths of the distribution). Heterogeneity was present by tumour grade (phet=0.01), with a lower risk of low-grade disease (OR=0.76, 95% CI 0.67-0.88) and a nonsignificantly higher risk of high-grade disease (OR=1.56, 95% CI 0.95-2.57). There was no evidence of heterogeneity by tumour stage. The observational design is a limitation.

CONCLUSIONS

Men with low circulating free testosterone may have a lower risk of overall prostate cancer; this may be due to a direct biological effect, or detection bias. Further research is needed to explore the apparent differential association by tumour grade.

PATIENT SUMMARY

In this study, we looked at circulating testosterone levels and risk of developing prostate cancer, finding that men with low testosterone had a lower risk of prostate cancer.

Randomized study of intravesical pirarubicin chemotherapy with low and intermediate-risk nonmuscle-invasive bladder cancer in Japan: Comparison of a single immediate postoperative intravesical instillation with short-term adjuvant intravesical instillations after transurethral resection

PURPOSE

The objective of this study was to evaluate the efficacy, defined by the 3-year tumor recurrence-free survival rate, of intravesical chemotherapy using pirarubicin (THP) in patients with low or intermediate-risk nonmuscle-invasive bladder cancer (NMIBC).

PATIENTS AND METHODS

Between October 2010 and January 2015, 206 patients were enrolled, and finally 113 were randomized to receive either a single immediate postoperative intravesical instillation of THP (30 mg) (Group A), or 8 additional weekly intravesical instillations of THP (30 mg) after a single postoperative instillation (Group B). The patients were examined by performing cystoscopy and urine cytology every 3 months after transurethral resection to determine bladder tumor recurrence. The primary endpoint was 3-year-recurrence-free survival rate.

RESULTS

All 113 patients were bacillus Calmette-Guérin (BCG)-naïve. The 3-year recurrence free survival rate was 63.7% for Group A and 85.3% for Group B (log-rank test, P = .0070). In patients with intermediate recurrence risk, the 3-year recurrence-free survival rate was 63.4% in Group A and 86.1% in Group B (log-rank test, P = .0036). Cox regression analysis revealed that only additional instillation of THP was a significant independent factor for recurrence-free rate in patients with intermediate risk. No patient with progression was noted during this period. Frequent adverse effects (AEs) were frequent urination and micturition pain, and no severe AEs (Grade 3 or more) occurred.

CONCLUSION

Additional instillation of THP (30 mg) weekly for 8 weeks reduced the risk of tumor recurrence without severe AEs in BCG-naïve NMIBC patients with intermediate risk.

Mevalonate pathway blockage enhances the efficacy of mTOR inhibitors with the activation of retinoblastoma protein in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common malignancy of kidney and remains largely intractable once it recurs after resection. mTOR inhibitors have been one of the mainstays used against recurrent RCC; however, there has been a major problem of the resistance to mTOR inhibitors, and thus new combination treatments with mTOR inhibitors are required. We here retrospectively showed that regular use of antilipidemic drug statins could provide a longer progression free survival (PFS) in RCC patients prescribed with an mTOR inhibitor everolimus than without statins (median PFS, 7.5 months vs. 3.2 months, respectively; hazard ratio, 0.52; 95% CI, 0.22-1.11). In order to give a rationale for this finding, we used RCC cell lines and showed the combinatorial effects of an mTOR inhibitor with statins induced a robust activation of retinoblastoma protein, whose mechanisms were involved in statins-mediated hindrance of KRAS or Rac1 protein prenylation. Finally, statins treatment also enhanced the efficacy of an mTOR inhibitor in RCC xenograft models. Thus, we provide molecular and (pre)clinical data showing that statins use could be a drug repositioning for RCC patients to enhance the efficacy of mTOR inhibitors.

Randomized study of intravesical chemotherapy using pirarubicin in patients with non-muscle-invasive bladder cancer in Japan: Comparing one immediate postoperative intravesical chemotherapy with short-term adjuvant intravesical chemotherapy after TURBT: Subanalysis in patients with intermediate risk

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Background: The objective is to evaluate the efficacy defining of 2-year tumor recurrence free rate of intravesical chemotherapy using pirarubicin (THP) for patients with intermediate risk. Methods: Between October 2010 and January 2015, 206 patients were enrolled in this study and finally 113 were randomized to one immediate postoperative intravesical instillation of THP 30mg (Group A), or additional intravesical instillation of THP 30mg weekly for 8 weeks after single postoperative instillation (Group B). The recurrent risk was stratified using EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder, the 2009 update. Of 113, 100 with intermediate risk were analyzed in this study. The patients were examined by cystoscopy and urine cytology every 3 months after trans urethral resection to determine bladder tumor recurrence. The primary endpoint was 2 year-recurrence-free survival rates. A statistical analysis was performed by SAS (SAS Institute Inc., Cary, USA). Results: The 2-year recurrence free survival rates were 66.2% in Group A and 86.1% in Group B, respectively (log rank test, p = 0.0043). In patients with recurrence score between 5 and 9, the 2-year recurrence free survival was 92.3% in Group B and 22.2% in Group A (log rank test, p = 0.0013). Cox regression analysis revealed that only additional instillation of THP was significant independent factor for recurrence free rate in patients with intermediate risk. There was no patient with progression during this period. Frequent adverse effects were frequent urination and micturition pain without severe adverse effect (Grade 3 or more). Limitation of this study is a failure to enroll sufficient number for statistical analysis. Conclusions: Additional instillation of THP 30mg weekly for 8 weeks reduced the risk of tumor recurrence without severe toxicity in NMIBC patients with intermediate recurrent risk.

A Meta-analysis of Individual Participant Data Reveals an Association between Circulating Levels of IGF-I and Prostate Cancer Risk

The role of insulin-like growth factors (IGF) in prostate cancer development is not fully understood. To investigate the association between circulating concentrations of IGFs (IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3) and prostate cancer risk, we pooled individual participant data from 17 prospective and two cross-sectional studies, including up to 10,554 prostate cancer cases and 13,618 control participants. Conditional logistic regression was used to estimate the ORs for prostate cancer based on the study-specific fifth of each analyte. Overall, IGF-I, IGF-II, IGFBP-2, and IGFBP-3 concentrations were positively associated with prostate cancer risk (Ptrend all ≤ 0.005), and IGFBP-1 was inversely associated weakly with risk (Ptrend = 0.05). However, heterogeneity between the prospective and cross-sectional studies was evident (Pheterogeneity = 0.03), unless the analyses were restricted to prospective studies (with the exception of IGF-II, Pheterogeneity = 0.02). For prospective studies, the OR for men in the highest versus the lowest fifth of each analyte was 1.29 (95% confidence interval, 1.16-1.43) for IGF-I, 0.81 (0.68-0.96) for IGFBP-1, and 1.25 (1.12-1.40) for IGFBP-3. These associations did not differ significantly by time-to-diagnosis or tumor stage or grade. After mutual adjustment for each of the other analytes, only IGF-I remained associated with risk. Our collaborative study represents the largest pooled analysis of the relationship between prostate cancer risk and circulating concentrations of IGF-I, providing strong evidence that IGF-I is highly likely to be involved in prostate cancer development. Cancer Res; 76(8); 2288-300. ©2016 AACR.

Risk Factors for Upper and Lower Urinary Tract Cancer Death in a Japanese Population: Findings from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study)

BACKGROUND

The incidence of bladder cancer is lower in Asian than in Western countries. However, the crude incidence and mortality of bladder cancer have recently increased in Japan because of the increased number of senior citizens. We have already reported risk factors for urothelial cancer in a large populationbased cohort study in Japan (JACC study). However, we did not evaluate the cancer risk in the upper and lower urinary tract separately in our previous study.

MATERIALS AND METHODS

Here we evaluated the risk of cancer death in the upper and lower urinary tracts, separately, using the database of the JACC study. The analytic cohort included 46,395 males and 64,190 females aged 40 to 79 years old. The Cox proportional hazard model was used to determine hazard ratios and their 95% confidence intervals.

RESULTS

Current smoking increased the risk of both upper and lower urinary tract cancer deaths. A history of kidney disease was associated with an increased risk of bladder cancer death, even after controlling for age, sex and smoking status.

CONCLUSIONS

The present study confirmed that current smoking increases the risk of both upper and lower urinary tract cancer deaths and indicated the possibility that a history of kidney disease may be a risk factor for bladder cancer death in the Japanese population.

Impact of p53 Status on Radiosensitization of Tumor Cells by MET Inhibition-Associated Checkpoint Abrogation

Signaling via the MET receptor tyrosine kinase has been implicated in crosstalk with cellular responses to DNA damage. Our group previously demonstrated that MET inhibition in tumor cells with deregulated MET activity results in radiosensitization via downregulation of the ATR-CHK1-CDC25 pathway, a major signaling cascade responsible for intra-S and G2-M cell-cycle arrest following DNA damage. Here we aimed at studying the potential therapeutic application of ionizing radiation in combination with a MET inhibitor, EMD-1214063, in p53-deficient cancer cells that harbor impaired G1-S checkpoint regulation upon DNA damage. We hypothesized that upon MET inhibition, p53-deficient cells would bypass both G1-S and G2-M checkpoints, promoting premature mitotic entry with substantial DNA lesions and cell death in a greater extent than p53-proficient cells. Our data suggest that p53-deficient cells are more susceptible to EMD-1214063 and combined treatment with irradiation than wild-type p53 lines as inferred from elevated γH2AX expression and increased cytotoxicity. Furthermore, cell-cycle distribution profiling indicates constantly lower G1 and higher G2-M population as well as higher expression of a mitotic marker p-histone H3 following the dual treatment in p53 knockdown isogenic variant, compared with the parental counterpart.

IMPLICATIONS

The concept of MET inhibition-mediated radiosensitization enhanced by p53 deficiency is of high clinical relevance, as p53 is frequently mutated in numerous types of human cancer. The current data point for a therapeutic advantage for an approach combining MET targeting along with DNA-damaging agents for MET-positive/p53-negative tumors.

Impact of maternal bifidobacteria and the mode of delivery on Bifidobacterium microbiota in infants

The aim of this study is to examine the influence of maternal intestinal and vaginal bifidobacteria on the colonisation of bifidobacteria in the gut of infants. Faecal samples from 120 healthy pregnant mothers within 1 month of delivery and from their infants at 1 month of age and 98 vaginal swabs from the mothers at the time of delivery were collected at a maternity hospital in Chiang Mai, Thailand. The faecal and vaginal samples were assayed by real-time PCR assays to detect Bifidobacterium species and to estimate the bifidobacterial copy numbers. After adjusting for the numbers of each Bifidobacterium species, delivery mode, and antibiotic use in infants by the age of 1 month, total counts of bifidobacteria in the mothers' faeces were associated with increased copy numbers of bifidobacteria in the faeces of breastfed infants. A caesarean section was also significantly associated with a decrease in the copy numbers of bifidobacteria in the faeces of infants. No significant correlation was found between the bifidobacterial copies of the vaginal swabs and those of the infants' faeces. The intestinal bifidobacterial status of exclusively breastfed infants was significantly positive affected by vaginal delivery and high bifidobacterial copy numbers in their mothers' gut.

Cigarette smoking and other risk factors for kidney cancer death in a Japanese population: Japan Collaborative Cohort Study for evaluation of cancer risk (JACC study)

BACKGROUND

Cigarette smoking is the largest single recognized cause of human cancers. In Western countries, many epidemiologists have reported risk factors for kidney cancer including smoking. However, little is known about the Japanese population.

MATERIALS AND METHODS

We evaluated the association of smoking with the risk of kidney cancer death in the Japan Collaborative Cohort (JACC) Study. Participants included 46,395 males and 64,190 females. The Cox proportional hazards model was used to determine age-and-sex adjusted relative risks.

RESULTS

A total of 62 males and 26 females died from kidney cancer during the follow-up of 707,136 and 1,025,703 person-years, respectively. Heavy smokers (Brinkman index >1200), fondness of fatty foods, hypertension, diabetes mellitus (DM), and obesity were suggested to increase the risk of renal cell carcinoma while walking was suggested to decrease the risk. Even after controlling for age, sex, alcohol drinking and DM, heavy smoking significantly increased the risk.

CONCLUSIONS

The present study suggests that six factors including smoking may increase and/or reduce the risk of kidney cancer in the Japanese population. Because of the small number of outcomes, however, we did not evaluate these factors after adjusting for all possible confounding factors. Further studies may be needed to confirm the findings in this study.

Clinical characteristics and oncological outcomes of testicular cancer patients registered in 2005 and 2008: the first large-scale study from the Cancer Registration Committee of the Japanese Urological Association

OBJECTIVES

To describe the clinical and pathological characteristics and oncological outcomes of testicular cancer diagnosed in Japan, we report the results of the testicular cancer registration carried out by the Japanese Urological Association.

METHODS

Testicular cancer survey was conducted by the Japanese Urological Association in 2011 to register newly diagnosed testicular cancers in 2005 and 2008. The survey included details such as age, presenting symptoms, physical examination findings, tumor markers, histopathology, clinical stage, initial treatment and clinical outcomes.

RESULTS

We analyzed 1121 cases of testicular primary germ cell tumor among 1157 registered patients. The median age was 37.0 years. Seminomas and non-seminomatous germ cell tumors accounted for 61.9% and 38.1%, respectively. Measurements of tumor markers were documented in 98.6% of the patients; however, there was an unsatisfactory uniform measurement of human chorionic gonadotropin, which made it difficult to evaluate the International Germ Cell Consensus Classification in all patients. The 1- and 3-year overall survival rates from the entire cohort were 98.3% and 96.8%, respectively. According to the International Germ Cell Consensus Classification, 3-year overall survival rates in the good, intermediate, and poor prognosis group were 99.1%, 100% and 79.9%, respectively.

CONCLUSIONS

The present report is the first large-scale study of the characteristics and survival of testicular cancer patients in Japan based on multi-institutional registry data, and showed a good prognosis even in an advanced stage. The improved survival attributed substantially to accurate diagnosis and effective multimodal treatment.

Fifteen-second skin icing using a frozen gel pack is effective for reducing goserelin injection pain

OBJECTIVE

The efficacy of skin icing to reduce the pain of goserelin injection has been reported. We investigated the optimal icing time with a frozen gel pack and its effectiveness.

METHODS

Abdominal skin temperatures of 49 healthy volunteers were measured after application of the frozen gel pack for 10, 15 and 30 s, and it was decided that a 15-second icing was adequate. For 55 consecutive patients who received goserelin (10.8 mg) injection, pain was evaluated employing a visual analog scale (VAS). The first injection was administered routinely. A second injection was administered after skin icing in 27 of 55 patients who wanted to try icing. At the time of the third injection, all patient decided whether they were to receive icing or the routine method.

RESULTS

After icing, VAS scores decreased in 20 of 27 patients. At the third injection, 18 patients requested icing.

CONCLUSION

When a patient complains of injection pain, the icing method should be considered for pain reduction.

Commensal microbiota modulate murine behaviors in a strictly contamination-free environment confirmed by culture-based methods

BACKGROUND

There is increasing evidence suggesting the existence of an interaction between commensal microbiota, the gut and the brain. The aim of this study was to examine the influence of commensal microbiota on the host behaviors in a contamination-free environment, which was verified by culture-based methods.

METHODS

Open-field and marble-burying tests were used to analyze anxiety-like behaviors and locomotor activity in gnotobiotic BALB/c mice with a common genetic background in a sterile isolator. The monoamine levels in several regions of the brain were measured in germfree (GF) mice and commensal fecal microbiota-associated mice (EX-GF).

KEY RESULTS

A 24-h exposure to the environment outside the sterile isolators rendered GF mice less anxious than those not contaminated, while there was no change in the locomotion. EX-GF mice, the gnotobiotic mice with normal specific pathogen-free microbiota, were less anxious and active than GF mice using open-field and marble-burying tests. The norepinephrine, dopamine, and serotonin turnover rates were higher in the EX-GF mice than in the GF mice in most regions of the brain, suggesting that monoaminergic neurotransmission might increase in the EX-GF mice comparing the GF mice. Monoassociation with Brautia coccoides reduced the anxiety level, but it did not affect the locomotor activity. In contrast, colonization with Bifidobacterium infantis decreased the locomotor activity, while having little effect on the anxiety level.

CONCLUSIONS & INFERENCES

These results strongly support the current view that gut microorganisms modulate brain development and behavior.

Everolimus treatment-associated interstitial lung disease (ILD) as a prognostic factor in Japanese patients with metastatic renal cell carcinoma

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Background: Interstitial lung disease (ILD) is one of the adverse events during treatment with everolimus for metastatic renal cell carcinoma (mRCC). Japanese study of everolimus treatment-associated ILD as a prognostic factor is rare. Methods: We retrospectively assessed the incidence and outcome of ILD in mRCC patients treated with everolimus. Between April 2010 and August 2012, 25 cases were treated with everolimus after the failure of one or two TKIs in our institute. All adverse events were graded in accordance with NCI CTCAE, version 3.0. Results: A total of 25 patients received treatment with everolimus and included 18 male and 7 female patients ranging in age from 21 to 84 years (median 62). According to MSKCC risk criteria, 6 cases were at favorable risk, 16 cases were at intermediate risk, and 3 cases were at poor risk. The median treatment term was 4 months (range 2-17 months). SD was reported in 19 cases and PD in 6 cases. Progression free survival was 3.5 months and overall survival was 12 months. ILD was found in 7 cases (28%). One was G1, five were G2, and one was G3. Corticosteroid therapy was initiated in 3 cases. In 5 of 7 ILD cases, everolimus was re-challenged. In our series, patients with ILD showed significantly better progression free survival than those without ILD (PFS was 8 months vs 3 months. Log-rank, P<0.001). There were no significant differences between the two groups in overall survival (12 months in patients with ILD vs 10 months in patients without ILD. Log-rank, NS). Conclusions: Everolimus appears to have been effective and well-tolerated in our institute. Re-challenge with everolimus was feasible after improving everolimus-induced ILD in cases of grade 1-2. To confirm these findings, the efficacy and AE profile of everolimus in Japanese patients should be investigated.

Incidence and outcome of interstitial lung disease (ILD) with everolimus treatment for metastatic renal cell carcinoma

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Background: Interstitial lung disease (ILD) is known as one of the adverse events during treatment with everolimus for metastatic renal cell carcinoma (mRCC). Methods: We retrospectively assessed the incidence and outcome of ILD in mRCC patients treated with everolimus. From April 2010 to August 2012, 25 cases were treated with everolimus after failure of one or two TKIs in our institute. All adverse events were graded in accordance with NCI CTCAE, version 3.0. Results: A total of 25 patients received treatment with everolimus. They included 18 male and 7 female patients ranging in age from 21 to 84 years (median 62). According to MSKCC risk criteria, 6 cases were at favorable risk, 16 cases were at intermediate risk, and 3 cases were at poor risk. Median treatment term was 4 months (range 2-17 months). SD was in 19 cases and PD was in 6 cases. Progression free survival was 3.5 months and overall survival was 12 months. ILD was found in 7 cases (28%). 1 was G1, 5 were G2 and 1 was G3. Corticosteroid therapy was initiated in 3 cases. In 5 of 7 ILD cases, everolimus was re-challenged. In our series, patients with ILD showed significantly better progression free survival than those without ILD (PFS was 8 months vs. 3 months. Log-rank, p < 0.001). There were no significant different between the 2 groups in over all survival (12 months in patients with ILD vs. 10 months in patients without ILD. Log-rank, NS). Conclusions: Everolimus appears to be effective and well-tolerated in our institute. Re-challenge of everolimus was feasible after improving of everolimus-induced ILD in cases of grade 1-2.

[Management of side effects of everolimus treatment for metastatic renal cell carcinoma]

Treatment with everolimus is known to prolong progression-free survival in patients with renal cell carcinoma resistant against tyrosine-kinase inhibitor therapy. The side effects must be known for more effective use of this drug. Information of side effects was collected from a randomized controlled study, the early post-marketing phase vigilance and from our own experience. Interstitial lung disease (ILD) was a potentially severe side effect. Incidence of ILD was relatively large compared with that of other target therapy agents. Infections, thrombocytopenia, stomatitis and others were experienced as other side effects. However, there were few uncontrollable side effects. Management of side effects of everolimus can be improved by obtaining sufficient knowledge.

Significance of serum tumor necrosis factor-related apoptosis-inducing ligand as a prognostic biomarker for renal cell carcinoma

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is endogenously expressed in immune cells and contributes to immunosurveillance for cancer. TRAIL induces apoptosis preferentially in various cancer cells, including renal cell carcinoma (RCC) cells. In this study, the serum TRAIL level was examined using an enzyme-linked immunosorbent assay in 52 healthy controls and in 84 RCC patients prior to surgery and its significance as a biomarker was evaluated. The median serum TRAIL level was lower in RCC patients compared to the healthy controls (55.9 vs. 103.1 pg/ml; P=0.019). RCC with lymph node metastasis (N1-2), distant metastasis (M1), stage III-IV, or microscopic venous invasion was associated with decreased serum TRAIL levels (P=0.032, 0.067, 0.020 and 0.011). When comparing serum TRAIL levels in the same RCC patients prior and subsequent to surgery (n=11), the levels were significantly higher after surgery (P=0.031). The cause-specific survival rate was significantly higher in RCC patients with high serum TRAIL levels compared to those with low serum TRAIL levels (P=0.0451). TRAIL was estimated to contribute 64 and 13% of the lymphocyte-mediated cytotoxicity against human RCC ACHN and Caki-1 cells, respectively. These data suggest that the serum TRAIL level may be useful as a prognostic biomarker in RCC patients.

High mobility group protein AT-hook 1 (HMGA1) is associated with the development of androgen independence in prostate cancer cells

BACKGROUND

We previously reported that the level of high mobility group protein AT-hook 1 (HMGA1) is low in androgen-dependent prostate cancer (PCa) cells (LNCaP), but is high in androgen-independent PCa cells (DU145 and PC-3) and that HMGA1 is a strong candidate gene playing a potential role in the progression of PCa. These findings have prompted us to evaluate the effect of HMGA1 on developing androgen independency, which is associated with the progression of PCa.

METHODS

Expression of HMGA1 in PCa cells and mouse tissues was examined by Western blot. In order to examine the effect of HMGA1 on cell growth under androgen-deprived condition, we transfected HMGA1 into LNCaP cells, and siRNA into both DU145 and PC-3 cells, respectively.

RESULTS

Androgen-deprivation induced an increase in the level of HMGA1 in LNCaP cells in vitro and in vivo, but did not in normal prostate tissue. Overexpression of HMGA1 maintained the cell growth of LNCaP under androgen-deprived condition. Furthermore, knockdown of HMGA1 suppressed the cell growth of DU145 and PC-3.

CONCLUSIONS

These data suggest that elevated expression of HMGA1 is associated with the transition of PCa cells from androgen-sensitive to androgen-independent growth and plays a role in the cell growth of androgen-independent PCa cells.

Clinical analysis of introduction chemotherapy for advanced germ cell tumors at Japanese high-volume center

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Background: Recently, cure rate of advanced testicular cancer even with poor prognostic factors have much improved. Inadequate treatment, however, may lead the patients "difficult-to-treat" situation. The aim of this study is to assess the results of the induction therapy at the Japanese single high volume center. Methods: We assessed clinical outcomes about 82 cases of advanced germ cell tumors that had induction chemotherapy at our hospital from Jun, 1998 until Dec, 2010. Results: Median age was 58 year-old (range:17-34y.o.). Seminoma was found in 16 cases (19.5%) and non-seminoma in 66 cases (80.5%), regarding primary histology. Clinical stageII was 37 cases, stageIIIA, IIIB, IIIC was 8, 24, 13 cases, respectively. IGCCC showed good in 41 cases (50%), intermediate 25 (30.5%), poor 15 (19.5%). BEP therapy was done in 74 (90.3%), EP 5 (6.1%), VIP 2 (2.4%) and PVB 1 (1.2%). Median cycles of induction therapy was 4 (range 1~5). Complete response was observed in 14 cases (17.1%), partial response with marker normalization in 58.5%, partial response without marker normalization in 12.2%, progressive disease in 8.5% including 4 cases of growing teratoma. RPLND after induction therapy was performed in 55 patients. Necrosis was found in 56.4%, teratoma only in 27.3% and viable cancer in 16.3%. Patients with salvage chemotherapy were 22 (27.5%) cases. Five- and 10-year overall survival was 93.3% and 89.6%, respectively. Clinical outcomes at 63 months of median follow-up was as follows; no evidence of disease 73 cases (89.0%), alive with disease 1case (2.4%) and death 7 cases (8.6%). Stratified by IGCCC, 5-year overall survival was 97.6% in good prognosis, 96.0% in intermediate prognosis and 79.0% in poor prognosis. Causes of death were as follows; pancreatic juice leakage after RPLND in 1 case, cerebral infarction in 1 case, cerebral bleeding in 1 case, traffic accident in 1 case, and cancer death in 3 cases. Conclusions: Clinical outcomes at Japanese high volume center were good, especially in good and intermediate prognosis. It was very clear that improvement of poor prognosis, especially high tumor volume, was required.

The usefulness of serum X-linked inhibitor of apoptosis protein (XIAP) for predicting recurrence of renal cell carcinoma

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Background: The X-linked Inhibitor of Apoptosis protein (XIAP) is associated with cell survival by blocking caspase-mediated apoptosis. We have reported the expression and prognostic value of XIAP in human prostate cancer using prostate tissue microarrays (Clin Cancer Res 2007). The expression and prognostic significance of XIAP in renal cell cancer (RCC) has been rarely studied. To our knowledge, no report on the serum XIAP levels from RCC patients has been published. In this study, we examined serum XIAP levels of RCC patients and normal individuals and evaluated its utility as biomarker. Methods: Peripheral blood samples were obtained from 99 patients (68 men and 31 women, median age; 60.7 years [36-85]) with RCC before surgery. All the patients underwent radical or partial nephrectomy. Blood samples were also collected from 52 healthy controls. The histological grade was as follows: grade 1; n= 5, grade 2; n=72, grade 3; n= 22. The serum XIAP levels were measured by a sandwich enzyme-linked immunosorbent assay. Cut off value was calculated by ROC analysis. Results: The serum XIAP levels in patients with RCC were higher than those of normal control individuals (328.3 pg/ml vs 156.2 pg/ml, p<0.001). At a median follow up of 33 months (1-105M), tumor with low serum XIAP showed significantly longer progression free survival (PFS) than those with high serum XIAP in grade 1-2 group (p<0.001). Conclusions: Serum XIAP level is associated with recurrence and prognosis. These results suggest that it may be used as a novel prognosticator and a potential target for renal cell cancer diagnosis and therapy.

Oncological outcomes of the prostate cancer patients registered in 2004: report from the Cancer Registration Committee of the JUA

OBJECTIVES

In 2001, the Cancer Registration Committee of the Japanese Urological Association initiated a data collection of prostate cancer patients into a computer-based database. The aim of the present study is to report the clinical and pathological characteristics and outcomes of prostate cancer patients diagnosed in 2004 in Japan.

METHODS

Overall, 11,385 patients from 239 institutions were registered into the database. After excluding 1105 patients because of insufficient data, duplication or insufficient follow up, 10,280 patients were eligible for the analysis. Most of them (10,198, 99.2%) were Japanese and 1195 (11.6%) had metastatic disease at the time of diagnosis. The mean and median follow up was 53.2 months and 61.5 months, respectively.

RESULTS

The 5-year overall and prostate cancer-specific survival rate was 89.7% and 94.8%, respectively. The 5-year prostate cancer-specific survival rate of M0 and M1 disease was 98.4% and 61.1%, respectively. For 8424 cases of organ-confined or regional disease, Japanese urologists used as the initial treatment hormone ablation therapy alone (3360, 39.9%), radical prostatectomy (3140, 38.1%), radiation therapy (1530, 18.2%) and watchful waiting (394, 4.7%) including active surveillance or palliative observation.

CONCLUSIONS

This is the first large population report of survival data in Japanese prostate cancer patients. In Japan, the disease population, survival period with metastatic disease and ratio of patients having hormone ablation therapy differ from those in Western countries.

Abstract 73: The transfection of high mobility group protein AT-hook 1 (HMGA1) is associated with the development of androgen independency in prostate cancer cells

The level of HMGA1 is low in androgen-dependent prostate cancer cell line (LNCaP), but is high in androgen-independent prostate cancer cell lines (DU145, PC-3). We have reported that the level of HMGA1 expression in prostate cancer cells is correlated with the extent of chromosomal aberrations (Can Res, 2002) and that transfection of HMGA1 into prostate cancer cell lines induces unbalanced chromosomal rearrangement and expression of matrix metalloproteinase 2 (Prostate, 2004). This suggests that HMGA1 is a strong candidate gene playing a potential role in the progression of prostate cancer. These findings have prompted us to evaluate the effect of HMGA1 on androgen independency, which is associated with the progression of prostate cancer. The androgen-dependent LNCaP cell line was induced to an androgen-independent subline (LN95) by being maintained for long term in the absence of androgen. The absence of androgen induced a 2.5-fold increase in the level of HMGA1 in the LN95 cell line. Androgen deprivation in vitro for 4 days as well as that for 8 days in vivo induced significant increase in the level of HMGA1 in parental LNCaP. On the other hand, the level of HMGA1 in normal prostate of mice 4 days and 11 days after castration as well as sham operation was almost undetectable. The cell proliferation rates of LNCaP cell transfected with HMGA1a vector (LN-H1) and LNCaP cell transfected with control empty vector (LN-EV) were determined with various concentrations (0-1nM) of dihydrotestosterone (DHT) by WST-8 assay in order to examine the effect of HMGA1 on androgen sensitivity. The expression of HMGA1 protein in LNH1 was confirmed to be 3.2-fold as high as that in LNEV. In low concentration (0-0.01 nM) of DHT, LNEV cell could not keep proliferation over day 6, while LNH1 could maintain proliferation over day 6. The cell proliferation rate at day 8 of LN-H1 grown in low concentration (0-0.01 nM) of DHT was about 2-fold higher than that of LN-EV. In contrast, both LN-H1 and LN-EV cells grew equally well in higher concentrations (0.1-1 nM) of DHT and could also keep proliferation over day6. Suppression of HMGA1 in DU145 and PC-3 by siRNA decreased cell proliferation rate and colony formation ability by 40% and 10-fold, respectively, in androgen-deprived medium. These data suggest that HMGA1 is associated with the transition of prostate cancer cells from androgen-sensitive to androgen-independent growth and plays a role in the cell growth of androgen-independent prostate cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 73. doi:1538-7445.AM2012-73

The usefulness of serum X-linked inhibitor of apoptosis protein (XIAP) for predicting recurrence of renal cell carcinoma

396

Background: The X-linked Inhibitor of Apoptosis protein (XIAP) is associated with cell survival by blocking caspase-mediated apoptosis. We have reported the expression and prognostic value of XIAP in human prostate cancer using prostate tissue microarrays (Clin Cancer Res 2007). The expression and prognostic significance of XIAP in renal cell cancer (RCC) has been rarely studied. To our knowledge, no report on the serum XIAP levels from RCC patients has been published. In this study, we examined serum XIAP levels of RCC patients and normal individuals and evaluated its utility as biomarker.

Methods: Peripheral blood samples were obtained from 99 patients (68 men and 31 women, median age; 60.7 years [36–85]) with RCC before surgery. All the patients underwent radical or partial nephrectomy. Blood samples were also collected from 52 healthy controls. The histological grade was as follows: Grade1; n= 5, Grade2; n=72, Grade3; n= 22. The serum XIAP levels were measured by a sandwich enzyme-linked immunosorbent assay. Cut off value was calculated by ROC analysis.

Results: The serum XIAP levels in patients with RCC were higher than those of normal control individuals (328.3 pg/ml vs 156.2 pg/ml, P<0.001). At a median follow up of 33 months (1-105M), tumor with low serum XIAP showed significantly longer progression free survival (PFS) than those with high serum XIAP in Grade 1-2 group (P<0.001).

Conclusions: Serum XIAP level is associated with recurrence and prognosis. These results suggest that it may be used as a novel prognosticator and a potential target for renal cell cancer diagnosis and therapy.

Abstract 606: Expression and role of high mobility group protein AT-hook 1 (HMGA1) in human renal cell carcinoma

Even though molecular targeted therapy has improved the clinical outcome of metastatic renal cell carcinoma (mRCC) patients, complete response is rarely observed. Identification of molecules possessing significant molecular functions in mRCC is mandatory for developing new therapeutic modalities for mRCC. High mobility group protein AT-hook 1 (HMGA1) is overexpressed in many types of cancer cells, but is not or at very low levels expressed in normal adult tissues. Expression of HMGA1 has been reported to be associated with metastatic potential and progression of cancer. We have reported that transfection of HMGA1 into prostate cancer cell lines induces chromosomal rearrangement (Cancer Res, 2002) and expression of matrix metalloproteinase 2 (Prostate, 2004) suggesting that HMGA1 may play an important role in the progression of prostate cancer. In this study, we examined expression and function of HMGA1 in human renal cell carcinoma (RCC). Expression of HMGA1 in six human RCC cell lines, Caki-1, ACHN, NC 65, RCC-4, 786-O, and A498, was examined by immunoblot and immunohistochemistry. The expression level of HMGA1 detected by immunoblot was Caki-1=ACHN&gt;NC65&gt;786-O, while RCC-4 and A498 barely expressed HMGA1. Immunohistochemistry showed nuclear localization of HMGA1 in these cell lines. Expression of HMGA1 in renal tumor tissue and normal kidney tissue from the same patients who underwent radical nephrectomy was examined by immunoblot. Immunoblot of surgical samples of 41 cases of RCC revealed that HMGA1 is not expressed in normal kidney tissues from all the cases. On the other hand, immunoblot showed that expression of HMGA1 was observed in 1 out of 23 (4%) non-metastatic cases (M0) compared to 6 out of 18 (33%) metastatic cases (M1) (P=0.031), and 3 out of 29 (10%) G1-2 cases compared to 4 out of 9 (44%) G3 cases (P=0.041). Colony formation assay and flowcytometry were performed using Caki-1 after transfecting with siRNA to knock down HMGA1. Knock-down of HMGA1 expression in Caki-1 cells by siRNA remarkably suppressed colony formation (control siRNA 86.0±5.3 vs HMGA1 siRNA 7.3±1.5, P&lt;0.001)and also induced apoptosis associated with increased subG1 fraction (control siRNA 1.9% vs HMGA1 siRNA 34.6%). These findings suggest that HMGA1 might be correlated with histological grade and metastatic potential of RCC associated with enhanced anti-apoptotic mechanism. No expression in normal kidney tissues, preferential expression in renal tumor tissues of metastatic cases, and remarkable suppression of colony formation by siRNA suggest that HMGA1 might be a potential target molecule for novel therapeutic modalities of mRCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 606. doi:10.1158/1538-7445.AM2011-606