Primary polyestradiol phosphate versus orchiectomy for advanced prostate cancer : Studies on the efficacy, cardiovascular complications and prognostic factors

Paikallisesti levinnyttä (T3-4 M0) ja luustoon levinnyttä (T1-4 M1) eturauhassyöpää sairastaneet potilaat satunnaistettiin kirurgiseen kastraatioon (orkiektomia) tai lääkkeelliseen kastraatioon lihaksensisäisellä polyestradiolifosfaatilla (PEP) annoksella 240 mg/kk. Verrattiin hoitojen kliinistä tehoa sekä sydän- ja verisuonikomplikaatioita (SV-komplikaatioita). Verrattiin myös hoitoa edeltäviä plasman testosteroni (T) ja estradioli (E2) pitoisuuksia T3-4 M0 ja T1-4 M1 potilaiden välillä sekä selvitettiin potilaiden yleistilan vaikutusta näihin hormonitasoihin. Lopuksi luotiin T1-4 M1 potilaille eturauhassyövän aiheuttaman kuoleman ennusteellinen riskiluokittelu kolmeen riskiryhmään käyttämällä hoitoa edeltäviä ennustetekijöitä. Kliinisessä tehossa ei orkiektomian ja PEP-hoidon välillä todettu tilastollisesti merkitsevää eroa. Odotetusti T1-4 M1 potilaiden ennuste oli huonompi kuin T3-4 M0 potilaiden. T1-4 M1 potilailla ei ollut SV-kuolemissa hoitoryhmien välillä tilastollista eroa, mutta ei-tappavia SV-komplikaatioita oli PEP ryhmässä (5.9%) enemmän kuin orkiektomia ryhmässä (2.0%). T3-4 M0 potilailla PEP-hoitoon liittyi tilastollisesti merkitsevä SV-kuolleisuus riski orkiektomiaan verrattuna (p = 0.001). PEP ryhmässä 67% kuolemista oli akuutteja sydäninfarkteja. Tämä PEP hoitoon liittyvä sydäninfarktiriski (mukaan lukien myös ei-tappavat sydäninfarktit) oli merkitsevästi pienempi potilailla, joiden hoitoa edeltävä E2 taso oli vähintään 93 pmol/l (p = 0.022). E2 taso oli merkitsevästi matalampi T1-4 M1 potilailla (74.7 pmol/l) kuin T3-4 M0 potilailla (87.9 pmol/l), mutta vastaavaa eroa ei ollut T tasoissa. Sekä T3-4 M0 että T1-4 M1 potilailla yleistilan lasku osittain selitti yksilöllisen T ja E2 tasojen laskun. Eturauhassyövän aiheuttaman kuoleman riskiryhmäluokittelu (Rg) kolmeen ryhmään luotiin käyttämällä alkalista fosfataasia (AFOS), prostata spesifistä antigeenia (PSA), laskoa (La) ja potilaan ikää. Yksi riskipiste annettiin, jos AFOS > 180 U/l (tällä hetkellä käytössä olevalla menetelmällä AFOS > 83 U/l), PSA > 35 µg/l, La > 80 mm/h ja ikä < 60 vuotta. Lopuksi pisteet laskettiin yhteen. Muodostettiin seuraavat ryhmät: Rg-a (0 -1 riskipistettä), Rg-b (2 riskipistettä) ja Rg-c (3 – 4 riskipistettä). Eturauhassyövän aiheuttama kuoleman riski lisääntyi merkitsevästi siirryttäessä riskiryhmästä seuraavaan (p < 0.001). Rg-luokittelu oli kliinisesti käytännöllinen ja hyvä havaitsemaan huonon ennusteen potilaat.

Oncolytic Adenoviruses with Radiation Therapy for Treatment of Prostate Cancer

Prostate cancer is the most common cancer in males. Although many patients with localized disease can be cured with surgery and radiotherapy, advanced disease and especially castration resistant metastatic disease remains incurable, with a median life expectancy of less than 18 months. Oncolytic adenoviruses (Ads) are a new promising treatment against cancer due to their innate capacity to kill cancer cells. Viral replication in tumor cells leads to oncolysis and production of a multiplicity of new virions that are capable of further destroying cancerous tissue. Oncolytic Ads can be modified for tumor targeted infection and replication and be armed with therapeutic transgenes to maximize the oncolytic effect. Worldwide, clinical trials with oncolytic Ads have demonstrated good safety while the antitumor efficacy remains to be improved. Importantly, the best responses have been reported when oncolytic adenoviruses have been combined with standard cancer treatments, such as chemotherapy and radiation. Further, a challenge in many virotherapy approaches has been the monitoring of virus replication in vivo. Reporter genes have been extensively used as transgenes to evaluate the biodistribution of the virus and activity of specific promoters. However, these techniques are often limited to preclinical evaluation and not amenable to human use. The aim of the thesis was to find and develop new oncolytic Ads with maximum efficacy against metastatic, castration resistant prostate cancer and study them in vitro and in vivo combined to different forms of radiation therapy. Using combination therapy, we were aiming for better antitumor efficacy with reduced side effects. Capsid modified Ads for enhanced transduction were studied. Serotype 3 targeted chimera, Ad5/3, was found to have enhanced infectivity for prostate cancer and was used for developing new viruses for the study. Correlation between Ad-encoded marker peptide secretion and simultaneous viral replication was evaluated and the effects of radiotherapy on viral replication were studied in detail. We found that the repair of double strand breaks caused by ionizing radiation was inhibited by adenoviral proteins and led to autophagic cell death. Both subcutaneous models and intrapulmonary tumor models mimicking metastatic, aggressive disease were used in vivo. Virus efficacy was evaluated by intratumoral injections. Also, intravenous administration was evaluated to study the effectiveness in metastatic disease. Oncolytic adenovirus treatment led to significant tumor growth control and increased the survival rate of the mice. These results were further improved when oncolytic Ads were combined with radiation therapy. Oncolytic Ads expressing human sodium/iodide transporter (hNIS) as a transgene were evaluated for their oncolytic potency and for the functionality of hNIS in vitro and in vivo. Monitoring of viral replication was also assessed using different imaging modalities relative to clinical use. SPECT imaging of tumor-bearing mice was evaluated and combined with simultaneous CT-scanning to obtain important anatomical information on biodistribution, also in a three-dimensional form. It was shown that hNIS-expressing adenoviruses could harbour a bi-functional transgene allowing for localization and imaging of viral replication. Targeted radiotherapy was applied by systemic radioiodide administration and resulted in iodide accumulation into Ad-infected tumor. The combination treatment showed significantly enhanced antitumor efficacy in mice bearing prostate cancer tumors. In summary, the results presented above aim to provide new treatment modalities for castration resistant prostate cancer. Molecular insights were provided for better understanding of the benefits of combined radiation therapy and oncolytic adenoviruses, which will hopefully facilitate the translation of the approach into clinical use for humans.

Estramustine and its Derivatives in Potentiating Radiotherapy of Prostate Cancer

The purpose of this study was to deepen our knowledge of the combined use of estramustine and radiotherapy in the treatment of prostate cancer. Prostate cancer is a common disease, with a high variability between subjects in its malignant potential. In many cases, the disease is an incidental finding with little or no clinical significance. In other cases, however, prostate cancer may be an aggressive malignant disease, which, if the initial treatment fails, lacks an effective cure and may lead to severe symptoms, metastasis, and death despite all treatment. In many cases, the methods of treatment available at the moment provide cure or significant regression of symptoms, but often at the cost of considerable side effects. Estramustine, a cytostatic drug used for treating advanced cancer of the prostate, has been shown to inhibit prostate cancer progression and also to increase the sensitivity of cancer cells to radiotherapy. The goals of this study were, first, to find out whether it is possible to use either estramustine or an antibody against estramustine binding protein as carrier molecules for bringing therapeutic radioisotopes into prostate cancer cells, and, secondly, to gain more understanding of the mechanisms behind the known radiosensitising effect of estramustine. Estramustine and estramustine binding protein antibody were labelled with iodine-125 to study the biodistribution of these substances in mice. In the first experiment, both of the substances accumulated in the prostate, but radioiodinated estramustine also showed affinity to the liver and the lungs. Since the radiolabelled antibody was found out to accumulate more selectively to the prostate, we studied its biodistribution in nude mice with DU-145 human prostate cancer implants. In this experiment, the prostate and the tumour accumulated more radioactivity than other organs, but we concluded that the difference in the dose of radiation compared to other organs was not sufficient for the radioiodinated antibody to be advocated as a carrier molecule for treating prostate cancer. Mice with similar DU-145 prostate cancer implants were then treated with estramustine and external beam irradiation, with and without neoadjuvant estramustine treatment. The tumours responded to the treatment as expected, showing the radiation potentiating effect of estramustine. In the third experiment, this effect was found without an increase in the amount of apoptosis in the tumour cells, despite previous suggestions to the contrary. In the fourth experiment, we gave a similar treatment to the mice with DU-145 tumours. A reduction in proliferation was found in the groups treated with radiotherapy, and an increased amount of tumour hypoxia and tumour necrosis in the group treated with both neoadjuvant estramustine and radiation. This finding is contradictory to the suggestion that the radiation sensitising effect of estramustine could be attributed to its angiogenic activity.

DNA damage recognition in the normal epithelium of human prostate and seminal vesicles

Prostate cancer is one of the most prevalent cancer types in men. The development of prostate tumors is known to require androgen exposure, and several pathways governing cell growth are deregulated in prostate tumorigenesis. Recent genetic studies have revealed that complex gene fusions and copy - number alterations are frequent in prostate cancer, a unique feature among solid tumors. These chromosomal aberrations are though to arise as a consequence of faulty repair of DNA double strand breaks (DSB). Most repair mechanisms have been studied in detail in cancer cell lines, but how DNA damage is detected and repaired in normal differentiated human cells has not been widely addressed. The events leading to the gene fusions in prostate cancer are under rigorous studies, as they not only shed light on the basic pathobiologic mechanisms but may also produce molecular targets for prostate cancer treatment and prevention. Prostate and seminal vesicles are part of the male reproductive system. They share similar structure and function but differ dramatically in their cancer incidence. Approximately fifty primary seminal vesicle carcinomas have been reported worldwide. Surprisingly, only little is known on why seminal vesicles are resistant to neoplastic changes. As both tissues are androgen dependent, it is a mystery that androgen signaling would only lead to tumors in prostate tissue. In this work, we set up novel ex vivo human tissue culture models of prostate and seminal vesicles, and used them to study how DNA damage is recognized in normal epithelium. One of the major DNA - damage inducible pathways, mediated by the ATM kinase, was robustly activated in all main cell types of both tissues. Interestingly, we discovered that secretory epithelial cells had less histone variant H2A.X and after DNA damage lower levels of H2AX were phosphorylated on serine 139 (γH2AX) than in basal or stromal cells. γH2AX has been considered essential for efficient DSB repair, but as there were no significant differences in the γH2AX levels between the two tissues, it seems more likely that the role of γH2AX is less important in postmitotic cells. We also gained insight into the regulation of p53, an important transcription factor that protects genomic integrity via multiple mechanisms, in human tissues. DSBs did not lead to a pronounced activation of p53, but treatments causing transcriptional stress, on the other hand, were able to launch a notable p53 response in both tissue types. In general, ex vivo culturing of human tissues provided unique means to study differentiated cells in their relevant tissue context, and is suited for testing novel therapeutic drugs before clinical trials. In order to study how prostate and seminal vesicle epithelial cells are able to activate DNA damage induced cell cycle checkpoints, we used primary cultures of prostate and seminal vesicle epithelial cells. To our knowledge, we are the first to report isolation of human primary seminal vesicle cells. Surprisingly, human prostate epithelial cells did not activate cell cycle checkpoints after DSBs in part due to low levels of Wee1A, a kinase regulating CDK activity, while primary seminal vesicle epithelial cells possessed proficient cell cycle checkpoints and expressed high levels of Wee1A. Similarly, seminal vesicle cells showed a distinct activation of the p53 - pathway after DSBs that did not occur in prostate epithelial cells. This indicates that p53 protein function is under different control mechanisms in the two cell types, which together with proficient cell cycle checkpoints may be crucial in protecting seminal vesicles from endogenous and exogenous DNA damaging factors and, as a consequence, from carcinogenesis. These data indicate that two very similar organs of male reproductive system do not respond to DNA damage similarly. The differentiated, non - replicating cells of both tissues were able to recognize DSBs, but under proliferation human prostate epithelial cells had deficient activation of the DNA damage response. This suggests that prostate epithelium is most vulnerable to accumulating genomic aberrations under conditions where it needs to proliferate, for example after inflammatory cellular damage.

Computation of restoration of ligand response in the random kinetics of a prostate cancer cell signaling pathway

Mutation and/or dysfunction of signaling proteins in the mitogen activated protein kinase (MAPK) signal transduction pathway are frequently observed in various kinds of human cancer. Consistent with this fact, in the present study, we experimentally observe that the epidermal growth factor (EGF) induced activation profile of MAP kinase signaling is not straightforward dose-dependent in the PC3 prostate cancer cells. To find out what parameters and reactions in the pathway are involved in this departure from the normal dose-dependency, a model-based pathway analysis is performed. The pathway is mathematically modeled with 28 rate equations yielding those many ordinary differential equations (ODE) with kinetic rate constants that have been reported to take random values in the existing literature. This has led to us treating the ODE model of the pathways kinetics as a random differential equations (RDE) system in which the parameters are random variables. We show that our RDE model captures the uncertainty in the kinetic rate constants as seen in the behavior of the experimental data and more importantly, upon simulation, exhibits the abnormal EGF dose-dependency of the activation profile of MAP kinase signaling in PC3 prostate cancer cells. The most likely set of values of the kinetic rate constants obtained from fitting the RDE model into the experimental data is then used in a direct transcription based dynamic optimization method for computing the changes needed in these kinetic rate constant values for the restoration of the normal EGF dose response. The last computation identifies the parameters, i.e., the kinetic rate constants in the RDE model, that are the most sensitive to the change in the EGF dose response behavior in the PC3 prostate cancer cells. The reactions in which these most sensitive parameters participate emerge as candidate drug targets on the signaling pathway. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Collision tumour involving a rectal gastrointestinal stromal tumour with invasion of the prostate and a prostatic adenocarcinoma

Background: Gastrointestinal stromal tumours (GISTs) are the most common primary mesenchymal neoplasia in the gastrointestinal tract, although they represent only a small fraction of total gastrointestinal malignancies in adults (<2%). GISTs can be located at any level of the gastrointestinal tract; the stomach is the most common location (60-70%), in contrast to the rectum, which is most rare (4%). When a GIST invades into the adjacent prostate tissue, it can simulate prostate cancer. In this study, we report on a case comprising the unexpected collision between a rectal GIST tumour and a prostatic adenocarcinoma. Findings: We describe the complexity of the clinical, endoscopic and radiological diagnosis, of the differential diagnosis based on tumour biopsy, and of the role of neoadjuvant therapy using imatinib prior to surgical treatment. Conclusions: Although isolated cases of coexisting GISTs and prostatic adenocarcinomas have reviously been described, this is the first reported case in the medical literature of a collision tumour involving a rectal GIST and prostatic adenocarcinoma components.

Efeito crônico da administração de esteróide anabólico androgênico na próstata de ratos

Esteróides anabólicos androgênicos (EAA) são usados por atletas profissionais e amadores, com o objetivo de melhorar a capacidade atlética, aparência e massa muscular. Muitos efeitos adversos têm sido associados com o abuso de EAA, incluindo doenças do trato urogenital. Este estudo teve como objetivo avaliar as alterações morfológicas no lobo ventral da próstata de ratos púberes e adultos cronicamente tratados com doses suprafisiológicas de EAA, usando métodos morfométricos. Foram estudados 39 ratos Wistar machos pesando entre 400 e 550 g. Os ratos foram divididos em quatro grupos: (a) ratos controle, com 105 dias de idade (C105) (n = 7); (b) ratos controle com 65 dias de idade (C 65) (n = 9), injectados com o veículo (óleo de amendoim); (c) ratos tratados com 105 dias de idade (T105) (n = 10) e (d) Os ratos tratados com 65 dias de idade (C 65) (n = 13). Os ratos tratados foram injectados com decanoato de nandrolona, numa dose de 10 mg.Kg-1 de peso corporal. O hormônio esteróide e o veículo foram administrados por via intramuscular, uma vez por semana, durante oito semanas. Os ratos foram sacrificados aos 161 dias de idade (C105 e T105) e 121 dias de idade (C65 e T65) e do lóbulo ventral da próstata foi dissecada e processada para histologia. A altura do epitélio acinar foi medida em micrômetros em fotomicrografias com ampliação de 400x. As densidades de superfície do lúmen do epitélio e estroma foram calculadas pelo método de contagem de pontos, com uma grade de 100 pontos sobrepostos sobre imagens ampliadas em 200x. Todas as análises foram realizadas com o software ImageJ. O teste t de Student e ANOVA foram utilizados para a comparação de médias. Foi considerado significativo quando p<0,05. O peso e volume do lobo ventral da próstata mostraram diferenças entre os grupos C65, T65, C105 e T105. A altura do epitélio não mostrou nenhuma diferença entre os grupos C65 e T65 (p = 0,8509), mas o grupo T105 mostrou um aumento de 32% em relação ao C105 (p = 0,0089). No que diz respeito à densidade de superfície do lúmen não houve diferença entre C65 e T65 (p = 0,9031) mas uma diminuição de 19% em relação a T105 em comparação com C105 (p = 0,0061). Não houve diferença na densidade de superfície do epitélio entre C65 e T65 (p = 0,7375), mas o grupo T105 apresentou 51% de aumento (p = 0,0065) em comparação com o C105. Em relação à densidade superficial do estroma, não foram observadas diferenças entre C65 e T65 e entre C105 e T105. Finalmente, não houve diferença no padrão de colágeno entre C105 e T105, mas o grupo T65 mostrou uma predominância de fibras de colágeno tipo I em relação ao C65. A utilização de esteróides androgênicos anabólicos em ratos promove mudanças estruturais na próstata. Observamos mudanças estruturais na altura, volume e epitélio do lobo da ventral da próstata e uma predominância de fibras de colágeno.