Treatment of prostate cancer by radioiodine therapy after tissue-specific expression of the sodium iodide symporter

Causing prostate cancer cells to express functionally active sodium iodide symporter (NIS) by targeted NIS gene transfer might offer the possibility of radioiodine therapy of prostate cancer. Therefore, we investigated radioiodine accumulation and therapeutic effectiveness of 131I in NIS-transfected prostate cancer cells in vitro and in vivo. The human prostatic adenocarcinoma cell line LNCaP was stably transfected with NIS cDNA under the control of the prostate-specific antigen promoter. The stably transfected LNCaP cell line NP-1 showed perchlorate-sensitive, androgen-dependent iodide uptake in vitro that resulted in selective killing of these cells by 131I in an in vitro clonogenic assay. Xenografts were established in athymic nude mice and imaged using a gamma camera after i.p. injection of 500 microCi of 123I. In contrast to the NIS-negative control tumors (P-1) which showed no in vivo uptake of 123I, NP-1 tumors accumulated 25-30% of the total 123I administered with a biological half-life of 45 h. In addition, NIS protein expression in LNCaP cell xenografts was confirmed by Western blot analysis and immunohistochemistry. After a single i.p. application of a therapeutic 131I dose (3 mCi), significant tumor reduction was achieved in NP-1 tumors in the therapy group compared with P-1 tumors and tumors in the control group. In conclusion, a therapeutic effect of 131I has been demonstrated in prostate cancer cells after induction of tissue-specific iodide uptake activity by prostate-specific antigen promoter-directed NIS expression in vitro and in vivo. This study demonstrates the potential of NIS as a novel therapeutic gene for nonthyroidal cancers, in particular prostate cancer.     

甲状腺乳头状癌BRAFV600E基因突变与钠碘同向转运体表达的研究

目的:探讨甲状腺乳头状癌(PTC)患者中BRAFV600E基因突变及钠碘同向转运体(NIS)蛋白的表达及两者间的相关性.方法:收集2008-01-01—2011-01-01青岛大学医学院附属医院病理科PTC石蜡包埋组织30例,其中癌旁组织为正常组织(G正常组)15例,癌旁组织为结节性甲状腺肿组织(G结甲组)15例.对PTC组织行DNA提取、PCR扩增、基因测序检测BRAFV600E基因突变,同时采用免疫组化的方法分析NIS蛋白表达,结果以免疫组化评分(IHS)表示.结果:30例PTC均无BRAFV600E基因突变;30例PTC组织中NIS蛋白表达,从0～12分,G正常组IHS=(7.92±3.01)分,G结甲组IHS=(6.58±2.71)分,两组NIS差异无统计学1意义,t=1.11,P=0.95;BRAFV600E突变与NIS蛋白表达无相关性.结论:尚未发现癌旁不同的PTCBRAFV600E基因有突变及NIS蛋白表达的差异.BRAFV600E基因突变与NIS表达在PTC中的关系有待进一步研究.     

Radiofrequency induction on sodium/iodide symporter expression of thyroid cancer

Objective:The aim of this study was to investigate the ef ects of radiofrequency treatment on sodium/iodide symporter expression of thyroid cancer cells. Methods:In 29 thyroid cancer patients with low or no expression of soda\iodide symporter, the radio frequency combined 131I therapy was used, the whole-body scintigraphy and serum Ig were detected before and after the radiofrequency treatment. Results:The whole-body scintigraphy showed that 4 cases (4/29) before radiofrequency treatment had positive iodine uptake, 19 cases (19/29) two weeks after radiofrequency treatment had the positive iodine uptake, 12 cases (12/29) four weeks after radiofrequency treatment had the positive iodine uptake. Four weeks after radiofrequency treatment, 5 cases had increased serum Ig levels, 17 cases had decreased serum Ig levels, 7 cases showed no change. 25 cases (25/29) were ef ective, 15 cases (15/29) were cured. Conclusion:The radiofrequency induced the non-expressed the sodium/iodide symporter of thyroid cancer cells regain the iodine intake ability, it improved the clinical ef icacy of 131I therapy in dedif erentiated thyroid cancer.     

钠/碘转运体在甲状腺癌中的表达

目的:探讨钠/碘转运体(sodium iodide symporter,NIS)在甲状腺癌组织中的表达.方法:应用实时荧光定量PCR(real-time fluorescence quantitative-PCR, RFQ-PCR)和免疫组织化学法检测NIS mRNA和蛋白在18例正常甲状腺组织、27例结节性甲状腺肿组织和23例甲状腺癌组织中的表达.结果: 甲状腺癌组织中NIS mRNA的表达显著低于正常甲状腺组织和结节性甲状腺肿组织(P=0.002).免疫组织化学检测结果表明,甲状腺癌组织中NIS蛋白主要定位于细胞质,强阳性表达13例(56.6%)、阳性表达3例(13.0%),强阳性表达率显著高于正常甲状腺组织(P=0.010).与正常甲状腺组织相比,甲状腺癌组织中NIS mRNA表达下降并且NIS蛋白表达升高者17例(74%),显著高于结节性甲状腺肿组织(χ2=4.428,P=0.035).结论:甲状腺癌组织中NIS mRNA的表达下降而NIS蛋白的表达增强,推测NIS蛋白主要位于细胞质可能是NIS不能发挥正常的运输功能,导致甲状腺癌患者不能聚碘的重要原因之一.     

Prostate-specific antigen (PSA) alone is not an appropriate surrogate marker of long-term therapeutic benefit in prostate cancer trials

The prostate-specific antigen (PSA) is the most studied marker of prostate cancer. It is used for screening and as indicator of disease evolution for individual patients. PSA being a prognostic factor is however not sufficient to justify using PSA-derived endpoints as surrogate for definitive survival endpoint in phase III trials. First, we clarify the terminology and requirements for a marker to be a valid surrogate endpoint. We then review the published literature pertaining to the validation of PSA endpoints as surrogate in all disease stages. We discuss the limitations of these studies and conclude that so far, PSA is not a validated surrogate endpoint in any of the disease settings and treatment conditions considered. We give some recommendations for the planning of trials that would use PSA endpoints (in hormone refractory disease) and for the early stop of (endocrine treatment) trials on the basis of intermediate results based on PSA.     

Probasin promoter (ARR(2)PB)-driven, prostate-specific expression of the human sodium iodide symporter (h-NIS) for targeted radioiodine therapy of prostate cancer

Prostate cancer is one of the most promising candidates for sodium iodide symporter (NIS)-mediated gene therapy. Adenovirus-mediated expression of NIS that is driven by prostate-specific promoters induces generous radioiodine accumulation in prostate cancer cells that may be used for therapy with (131)I. We have recently developed a replication-deficient adenovirus carrying the human NIS cDNA linked to a composite probasin promoter, ARR(2)PB, aiming toward specific expression of the human NIS gene (h-NIS) in prostate tissue for targeted radioactive iodide therapy of prostate cancer (Ad-ARR(2)PB/hNIS). The ability of Ad-ARR(2)PB/hNIS to cause NIS expression in tumor cells was characterized by iodide uptake assay and compared with Ad-CMV/hNIS in which the h-NIS expression is driven by the cytomegalovirus (CMV) promoter. Androgen-dependent prostate cancer cell lines (LNCaP) and non-prostate origin tumor cell lines (SNU449, MCF-7, HCT116, OVCAR-3, and Panc-1) were infected with the viral constructs, and perchlorate-sensitive (125)I uptake and NIS protein expression were measured. Ad-ARR(2)PB/hNIS-infected LNCaP cells showed androgen-dependent and perchlorate-sensitive iodide uptake. Iodide accumulation in LNCaP cells infected with Ad-ARR(2)PB/hNIS, followed by incubation with synthetic androgen, was 5.3-fold increased compared with those coincubated with perchlorate (15,184 +/- 1,173 cpm versus 2,837 +/- 187 cpm). Ad-ARR(2)PB/hNIS-infected LNCaP cells revealed a 3.2-fold increase of iodide accumulation compared with those infected with Ad-CMV/hNIS (multiplicity of infection = 30). Iodide uptake in a panel of non-prostate tumor cell lines infected with Ad-ARR(2)PB/hNIS was no more than 2,500 cpm, demonstrating the tissue specificity of this construct. These results indicate that Ad-ARR(2)PB/hNIS can be used to achieve high-magnitude and tissue-specific expression of h-NIS in prostate tissue and is a promising candidate for cancer gene therapy of prostate cancer.     

细胞因子对乳腺癌细胞钠碘转运体基因表达的调控

目的本实验通过三种细胞因子(肿瘤坏死因子-α,干扰素-γ和白细胞介素-6)对乳腺细胞钠碘转运体(NIS)基因表达的影响,探讨乳腺肿瘤组织NIS的表达特点和调控因素.方法采用乳腺癌细胞MCF-7和MB453进行培养,分别给予不同浓度的肿瘤坏死因子-α,干扰素-γ或白细胞介素-6刺激72 h.采用RT-PCR方法检测细胞中NIS mRNA表达情况.结果乳腺癌细胞在经过肿瘤坏死因子-α,干扰素-γ或白细胞介素-6刺激后,细胞中NIS的mRNA表达比对照组明显降低,并且与细胞因子浓度呈负相关.结论肿瘤坏死因子-α,干扰素-γ和白细胞介素-6对乳腺癌细胞MCF-7和MB453的NIS基因mRNA表达有抑制作用,这提示细胞因子可能通过调节乳腺癌NIS基因mRNA的表达,从而影响乳腺癌细胞对放射性碘治疗的敏感性.     

Low expression of sodium iodide symporter identifies aggressive thyroid tumors

A decreased radioiodine uptake is frequently detected in differentiated thyroid carcinomas (DTC) and is associated with high recurrence rate and reduced survival. We investigated the correlation between NIS mRNA expression levels in the primary tumor and patient outcome using a quantitative real-time RT-PCR method. NIS expression was decreased in 17 DTC (21.04+/-39.66 pg Eq) compared to four autoimmune thyroid disease (180.51+/-92.63 pg Eq) and 14 normal tissues (75.71+/-66.98 pg Eq) (p<0.0001). The 17 thyroid differentiated carcinoma patients were submitted to surgery complemented by radioiodine ablation and had at least 24 months of follow-up, under levothyroxine continued suppressive therapy. According to their outcome, we could characterize a group of papillary carcinoma patients with aggressive carcinomas, whose NIS mRNA levels were markedly lower than a group with non-aggressive carcinomas (0.62+/-0.79 versus 54.87+/-53.79; p<0.005). We suggest that the quantification of NIS mRNA relative levels in the primary tumor may predict poor outcome.     

Rat sodium iodide symporter for radioiodide therapy of cancer.

Design and development of new approaches for targeted radiotherapy of cancer and improvement of therapeutic index by more local radiation therapy are very important issues. Adenovirus-mediated delivery of the sodium iodide symporter (NIS) gene to cancer cells is a powerful technique to concentrate lethal radiation in tumor cells and eradicate tumors with increased therapeutic index. A replication-defective adenoviral vector expressing the rat NIS gene (Ad-rNIS) was used for in vitro gene delivery and into human prostate cancer xenografts to study antitumor effect. Robust function of the rat symporter was detected in DU145, T47D, and HCT-15 human cancer cell lines transduced with Ad-rNIS. All three cancer cell lines successfully transferred functionally active rat symporter to the plasma membrane, resulting in very high levels of iodine-125 accumulation. Three-dimensional multicellular tumor spheroids derived from DU145 human prostate cancer cells were transduced with Ad-rNIS and incubated with (131)I for 24 hours. After treatment, spheroids rapidly decreased in size and disappeared within 10 days. In vivo data revealed an inhibition of tumor growth in athymic nude mice after intratumoral Ad-rNIS injection followed by (131)I administration. Eighty-eight percent of experimental mice survived >30 days, whereas control groups had only 18% survival >30 days. This is the first report that demonstrates the rat NIS gene can effectively induce growth arrest of human tumor xenografts after in vivo adenoviral gene delivery and (131)I administration. The data confirm our hypothesis that the rat NIS gene is an attractive suicide gene candidate for cancer treatment.     

Targeting sodium/iodide symporter gene expression for estrogen-regulated imaging and therapy in breast cancer

Expression of the sodium iodide symporter (hNIS) has been detected in breast cancer tissue, but frequently, not at the levels necessary to mediate (131)I accumulation. Transducing the hNIS gene into breast cancer cells with adenovirus could be a tractable strategy to render breast cancer susceptible to radioiodide therapy. We constructed the replication-incompetent virus, AdSERE, in which an estrogen-responsive promoter directs the expression of hNIS. In vitro, we demonstrate that AdSERE mediates hNIS expression and iodide uptake in ER+ breast cancer cells. In vivo, we show that AdSERE-infected ER+ tumors can be imaged due to tracer accumulation; in addition, AdSERE in combination with therapeutic doses of (131)I suppresses tumor growth.     

Dual therapy of ovarian cancer using measles viruses expressing carcinoembryonic antigen and sodium iodide symporter.

PURPOSE: MV-CEA is an oncolytic measles virus currently being tested in patients with ovarian cancer and whose propagation can be monitored by measuring blood carcinoembryonic antigen (CEA) levels. MV-NIS is an oncolytic measles virus coding for the thyroidal sodium iodide symporter (NIS) whose propagation can be mapped by serial radioiodine imaging. Expression of both CEA and NIS genes from a single virus would combine sensitive, quantitative expression monitoring (CEA) with radioisotopic expression mapping (NIS). Because of the unfavorable replication kinetics of measles viruses expressing both CEA and NIS, we explored the feasibility of combining MV-CEA with MV-NIS for comprehensive virotherapy monitoring in ovarian cancer. EXPERIMENTAL DESIGN AND RESULTS: Mice implanted with i.p. SKOV3ip.1 ovarian cancer xenografts received MV-CEA alone, MV-NIS alone, or a combination of MV-CEA plus MV-NIS. Viral gene expression was monitored by measuring blood CEA levels, and the location of virus-infected cells was monitored by gamma camera imaging. Surprisingly, mice receiving the combination of MV-CEA plus MV-NIS showed greatly superior responses to therapy, but this was associated with 10-fold lower plasma levels of CEA compared with mice treated with MV-CEA alone. In vitro studies showed superior replication kinetics of MV-NIS relative to MV-CEA. The gamma camera scans were considerably less sensitive than the plasma CEA marker for monitoring virus infection. CONCLUSIONS: Dual therapy with MV-CEA and MV-NIS is superior to treatment with either virus alone, and it allows noninvasive monitoring of virotherapy via soluble marker peptide and gamma camera imaging. This has important implications for the clinical development of oncolytic measles viruses.     

全反式维甲酸对甲状腺癌细胞NIS基因表达及吸碘能力影响的实验研究

目的：探讨全反式维甲酸（ATRA）对甲状腺癌细胞株钠/碘同向转运体（NIS）基因表达、吸碘能力的影响,为ATRA用于放射性碘治疗甲状腺癌提供理论依据。方法：分别以不同浓度（10^-7mol/L、10^-6mol/L、10^-5mol/L、10^-4mol/L）的ATRA处理体外培养的甲状腺癌细胞株（FTC-133）,48h后利用半定量RT-PCR检测细胞NISmRNA表达,γ-计数仪检测细胞吸碘能力。结果：ARTA浓度在（0～10%-5）mol/L范围内,细胞NIS基因表达及吸碘能力随ARTA剂量的增加而增加（P〈0.05）。当ARTA浓度达10%-4mol/L时,增加与前一浓度相比无统计学意义（P〉0.05）。结论：ATRA可上调甲状腺癌FTC-133细胞NIS基因表达,增强其吸碘能力,而且这种作用在一定浓度范围内具有剂量依赖性。     

Low expression of sodium iodide symporter expression in aggressive variants of papillary thyroid carcinoma

Background

A decreased radioiodine uptake is associated with high recurrence rate and reduced survival in papillary thyroid carcinoma (PTC). Sodium iodide symporter (NIS) expression status in aggressive PTC variants is unknown.

Methods

NIS expression in conventional PTC and aggressive PTC variants such as tall cell variant (TCV) and diffuse sclerosing variant (DSPTC) was investigated using immunohistochemical detection.

Results

Patients having TCV and DSPTC were significantly more likely to have extrathyroidal extension and lymph nodes metastases (P < 0.05). Positive NIS staining was identified in 228 of 312 (73.1 %) patients with conventional PTC, 9 of 28 (32.1 %) patients with TCV and 12 of 30 (40.0 %) patients with DSPTC. NIS expression distinguished conventional PTC from TCV and DSPTC significantly (P < 0.01).

Conclusion

Due to their low NIS expression, TCV and DSPTC need higher cumulative doses of radioactive iodine therapy to improve their prognosis.     

The rat sodium iodide symporter gene permits more effective radioisotope concentration than the human sodium iodide symporter gene in human and rodent cancer cells

Expression of the sodium iodide symporter (NIS) gene in tumor cells may provide a novel mechanism for treating cancer. The NIS mediates the normal physiological transport of iodide across the thyroid cell membrane. This mechanism of iodide uptake has been used to both diagnose and treat thyroid cancer. Tissue expression of the NIS is largely limited to the thyroid; therefore, expression of the NIS gene in cancer cells would allow for specific iodine uptake, radioisotope accumulation, and treatment. In this study, we directly compared the human and rat NIS (rNIS) for their ability to concentrate radioisotope into human and rodent cancer cells. Perchlorate-sensitive (125)I uptake in multiple cell lines was demonstrated following transduction with retroviral vectors expressing either the human or rNIS gene. Surprisingly, iodine uptake was consistently higher with the rNIS gene, up to 5-fold greater, when compared to the human gene, even within a variety of human tumor cell lines. This iodine uptake allowed for cell killing following (131)I treatment in NIS-transduced cells when assayed by in vitro clonogenic assays. These results demonstrate that the rNIS gene provides superior iodine uptake ability, and may be preferable for use in designing anticancer gene therapy approaches.     

Prostate-specific antigen use among men without prostate cancer in France (2008-2010)

This study evaluated the rate of prostate-specific antigen (PSA) dosage in men age 40 or older, affiliated to the general social security system in France between 2008 and 2010: 10.9 million men, excluding those with known prostate cancer. In 2010, 30.7% of this male population had at least one dosage of PSA, i.e. 12.3% of those between 40 and 54, 47.7% of those between 55 and 74, and 47.6% of those 75 years old or older. Percentages of men who had at least one dosage in the three-year period were 26.2%, 77.3% and 75.6% for the same age brackets, respectively. Overall, 13% of men age 40 or older, and in particular 21% of men 75 years old or older had more than three PSA dosages during the three-year time period. Eighty-eight percent of PSA dosages performed in 2010 were prescribed by a general practitioner and 3.2% by an urologist. Conflicting with French and internationally published recommendations regarding PSA dosage, the present results demonstrate a shift toward chaotic mass screening of prostate cancer particularly in men aged 75 or older.