Exosomes-Promising Carriers for Regulatory Therapy in Oncology.

Extracellular vesicles (EVs), including exosomes and microvesicles, together with apoptotic bodies form a diverse group of nanoparticles that play a crucial role in intercellular communication, participate in numerous physiological and pathological processes. In the context of cancer, they can allow the transfer of bioactive molecules and genetic material between cancer cells and the surrounding stromal cells, thus promoting such processes as angiogenesis, metastasis, and immune evasion. In this article, we review recent advances in understanding how EVs, especially exosomes, influence tumor progression and modulation of the microenvironment. The key mechanisms include exosomes inducing the epithelial-mesenchymal transition, polarizing macrophages toward protumoral phenotypes, and suppressing antitumor immunity. The therapeutic potential of engineered exosomes is highlighted, including their loading with drugs, RNA therapeutics, or tumor antigens to alter the tumor microenvironment. Current techniques for their isolation, characterization, and engineering are discussed. Ongoing challenges include improving exosome loading efficiency, optimizing biodistribution, and enhancing selective cell targeting. Overall, exosomes present promising opportunities to understand tumorigenesis and develop more targeted diagnostic and therapeutic strategies by exploiting the natural intercellular communication networks in tumors. In the context of oncology, regulatory therapy provides the possibility of reproducing the original conditions that are unfavorable for the existence of the cancer process and may thus be a feasible alternative to population treatments. We also review current access to the technology enabling regulatory intervention in the cancer process using exosomes.

HPV RNA and DNA testing in Polish women screened for cervical cancer - A single oncological center study.

OBJECTIVES: To evaluate the incidence of HPV infection, and the frequency of the various genotypes, using mRNA and DNA testing; to assess their relationship with the cervical lesions and women's age in the Polish patients. STUDY DESIGN: A group of 1840 women, most of whom had abnormal cytology, from the Franciszek Lukaszczyk Oncology Centre in Bydgoszcz, Poland were screened for presence of at least one of 13 high risk HPV. Following that, 545 HPV DNA positive women were tested for HPV infection using HPV mRNA with the Nucleic Acid Sequence-Based Amplification Assay (NASBA) method. RESULTS: In our study group, 70.1% had DNA HPV positive results. Only 4% of the women had normal cytology. Among 545 HPV DNA positive patients, 36.3% had HPV mRNA positive tests. Moreover, 48% of the HPV mRNA positive patients were infected with HPV 16, followed by 18 (12.6%), 31 (10.1%), 33 (8.6%%), 45 (4.5%), and 16.2% of HPV mRNA positive women were infected with more than one HPV genotype. Furthermore, we found that in women under 30, HPV DNA positivity was higher than HPV mRNA positivity, supporting the hypothesis that younger women's infections are mostly temporary. CONCLUSIONS: The differences in HPV prevalence and genotype distribution observed in our study may have an impact on the efficacy of HPV vaccinations for cervical cancer and the development of screening programs, which should be examined further in future studies.

Association among Vitamin D, Retinoic Acid-Related Orphan Receptors, and Vitamin D Hydroxyderivatives in Ovarian Cancer.

Vitamin D and its derivatives, acting via the vitamin D receptor (VDR) and retinoic acid-related orphan receptors γ and α (RORγ and RORα), show anticancer properties. Since pathological conditions are characterized by disturbances in the expression of these receptors, in this study, we investigated their expression in ovarian cancers (OCs), as well as explored the phenotypic effects of vitamin D hydroxyderivatives and RORγ/α agonists on OC cells. The VDR and RORγ showed both a nuclear and a cytoplasmic location, and their expression levels were found to be reduced in the primary and metastatic OCs in comparison to normal ovarian epithelium, as well as correlated to the tumor grade. This reduction in VDR and RORγ expression correlated with a shorter overall disease-free survival. VDR, RORγ, and RORα were also detected in SKOV-3 and OVCAR-3 cell lines with increased expression in the latter line. 20-Hydroxy-lumisterol3 (20(OH)L3) and synthetic RORα/RORγ agonist SR1078 inhibited proliferation only in the OVCAR-3 line, while 20-hydroxyvitamin-D3 (20(OH)D3) only inhibited SKOV-3 cell proliferation. 1,25(OH)2D3, 20(OH)L3, and SR1078, but not 20(OH)D3, inhibited spheroid formation in SKOV-3 cells. In summary, decreases in VDR, RORγ, and RORα expression correlated with an unfavorable outcome for OC, and compounds targeting these receptors had a context-dependent anti-tumor activity in vitro. We conclude that VDR and RORγ expression can be used in the diagnosis and prognosis of OC and suggest their ligands as potential candidates for OC therapy.

Wilms' tumor 1 antigen immunoreactivity in epithelial ovarian cancer - diagnostic and prognostic value.

OBJECTIVES: Ovarian cancer is a heterogeneous disease, with a number of different histological subtypes with various responses to treatment. Wilms' tumor 1 (WT1) immunoreactivity is used to distinguish between OC's various subtypes. However, little is known about the protein's role as a prognostic factor. Thus, the main aim of our study was to evaluate the relationship between WT1 expression and patient overall survival (OS) and lymph node metastases. MATERIALS AND METHODS: Study group consisted of 164 women aged 22-84, diagnosed with epithelial ovarian cancer (EOC). WT1 expression in histological slides was assessed by immunohistochemistry. RESULTS: Serous tumors were the most common subtype among EOC (n = 126; 76.8%), followed by endometrioid (n = 20; 12.2%), clear-cell (n = 14; 8.5%) and mucinous cancer (n = 4; 2.4%). Of all serous EOC, WT1-positive tumors accounted for 75.6% of cases and this number was significantly higher than in other histological subtypes (p < 0.0001). Patients with lymph node metastases were more likely to have WT1-positive than WT1-negative tumors (p = 0.006). There was no significant correlation between WT1 immunoreactivity and OS across the whole study group of EOC patients (p = 0.6); however, in the group of non-serous (mucinous, endometrioid and clear-cell) EOC subjects, WT1 immunoreactivity was associated with shorter OS (p = 0.046). CONCLUSIONS: WT1 immunoreactivity may be helpful in differentiating primary epithelial serous carcinomas from non-serous ovarian cancers; however, its prognostic role in EOC is rather uncertain.

Cytoplasmic and membranous receptor-binding cancer antigens expressed on SiSo cells (RCAS1) immunoreactivity in epithelial ovarian cancer cells represent differing biological function of RCAS1.

INTRODUCTION: Receptor-binding cancer antigen expressed on SiSo cells (RCAS1) is a selective suppressor of the immune response that has been linked to the evasion of immune surveillance by cancer cells. However, the exact prognostic impact of RCAS1 on epithelial ovarian cancer (EOC) has not been fully elucidated. The main aim of our study was to evaluate the influence of RCAS1 immunoreactivity (RCAS1-Ir) in EOC cells and in tumor stroma cells on patient overall survival. We also focused on RCAS1-Ir and the structure of the tumor stroma. MATERIAL AND METHODS: RCAS1-Ir was evaluated by means of immunohistochemistry in 67 patients with EOC. We distinguished cytoplasmic and membranous immunoreactivity patterns. RESULTS: We found that high cytoplasmic RCAS1-Ir in cancer cells was associated with more than a two-time shortened period of overall survival. Membranous RCAS1-Ir in cancer cells, as well as in tumor stroma macrophages and fibroblasts, did not correlate with patient survival. RCAS1-Ir in the cytoplasm of cancer cells was positively correlated with the degree of tumor stroma infiltration by fibroblasts and macrophages, but not with RCAS1-Ir in these cells. On the other hand, membranous RCAS1-Ir in cancer cells was positively correlated with RCAS1-Ir in fibroblasts and macrophages, but not with their quantity. CONCLUSIONS: Due to their different impacts on patient prognosis and tumor stroma structure, it seems that cytoplasmic and membranous RCAS1-Ir in EOC cells may have different biological functions.

On the relationship between VDR, RORα and RORγ receptors expression and HIF1-α levels in human melanomas.

We analysed the correlation between the expression of HIF-1α (hypoxia-inducible factor 1 alpha), the nuclear receptors: VDR (vitamin D receptor), RORα (retinoic acid receptor-related orphan receptor alpha), and RORγ and CYP24A1 (cytochrome P450 family 24 subfamily A member 1) and CYP27B1 (cytochrome P450 family 27 subfamily B member 1), enzymes involved in vitamin D metabolism. In primary and metastatic melanomas, VDR negatively correlated with nuclear HIF-1α expression (r = -.2273, P = .0302; r = -.5081, P = .0011). Furthermore, the highest HIF-1α expression was observed in pT3-pT4 VDR-negative melanomas. A comparative analysis of immunostained HIF-1α and CYP27B1 and CYP24A1 showed lack of correlation between these parameters both in primary tumors and melanoma metastases. In contrast, RORα expression correlated positively with nuclear HIF-1α expression in primary and metastatic lesions (r = .2438, P = .0175; r = .3662, P = .0166). Comparable levels of HIF-1α expression pattern was observed in localized and advanced melanomas. RORγ in primary melanomas correlated also positively with nuclear HIF-1α expression (r = .2743, P = .0129). HIF-1α expression was the lowest in localized RORγ-negative melanomas. In addition, HIF-1α expression correlated with RORγ-positive lymphocytes in melanoma metastases. We further found that in metastatic lymph nodes FoxP3 immunostaining correlated positively with HIF-1α and RORγ expression in melanoma cells (r = .3667; P = .0327; r = .4208, P = .0129). In summary, our study indicates that the expression of VDR, RORα and RORγ in melanomas is related to hypoxia and/or HIF1-α activity, which also affects FoxP3 expression in metastatic melanoma. Therefore, the hypoxia can affect tumor biology by changing nuclear receptors expression and molecular pathways regulated by nuclear receptors and immune responses.

Vitamin D receptors (VDR), hydroxylases CYP27B1 and CYP24A1 and retinoid-related orphan receptors (ROR) level in human uveal tract and ocular melanoma with different melanization levels.

In recent years, a significant number of studies have investigated the preventive role of vitamin D in a number of different neoplasms. In this study, we analyze various components of the vitamin D signaling pathways in the human uveal tract and uveal melanoma, including analysis of the expression of vitamin D receptors (VDR), the activating and inactivating hydroxylases, respectively, CYP27B1 and CYP24A1, and the retinoic acid-related orphan receptors (ROR) α (RORα) and γ (RORγ) in these tissues. We further analyzed the expression of VDR, CYP27B1, CYP24A1, and ROR in relation to melanin levels, clinical stage and prognosis. Our study indicated that the uveal melanoma melanin level inversely correlated with VDR expression. We further showed that vitamin D is metabolized in uveal melanoma. This is significant because until now there has been no paper published, that would describe presence of VDR, hydroxylases CYP27B1 and CYP24A1, and RORα and RORγ in the human uveal tract and uveal melanomas. The outcomes of our research can contribute to the development of new diagnostic and therapeutic methods in uveal tract disorders, especially in uveal melanoma. The presented associations between vitamin D signaling elements and uveal melanoma in comparison to uveal tract encourage future clinical research with larger patients' population.

Analysis of the treg cell population in the peripheral blood of ovarian cancer patients in relation to the long-term outcomes.

OBJECTIVES: There is growing evidence that Treg cell infiltration into the cancer nest is associated with poor prognosis. How- ever, the Treg cell population in the peripheral blood may change when a different type of anticancer therapy is applied. Since Treg cells may support tumor growth by enhancing the suppressive profile of the cancer microenvironment, the assessment of Treg cells can bring to light important information regarding prognosis. Thus we decided to analyze the Treg cell population in the peripheral blood in relation to long-term outcomes in the group of patients with ovarian cancer. MATERIAL AND METHODS: The 80 patients included in the study were treated surgically followed by chemiotherapy for ovar- ian cancer between October 2010 through May 2011.The peripheral blood samples from the patients were collected directly prior to chemotherapy. Information on any patients who died was retrieved from the database of the Cuiavia-Pomerania Regional Office of the National Health System of Poland. CD4+CD25+FOXP3+ lymphocytes T were assed by flow cytometry. We have analyzed the long term outcomes of treatment regarding to the level of Treg cells in peripheral blood. RESULTS: We found that patients with serous adenocarcinomas had significantly higher Treg levels compared to those patients with non-serous types. Patients who had a higher percentage of Treg cells within the CD4+ cell population prior to the beginning of the treatment had worse long-term outcomes from the applied therapy. CONCLUSIONS: The assessment of Treg levels prior to the start of chemotherapy is clinically useful and may predict overall survival in ovarian cancer patients.

High tumor cell vimentin expression indicates prolonged survival in patients with ovarian malignant tumors.

OBJECTIVES: The main aims of the study were to investigate the expression of vimentin and its correlation with the overall survival (OS) of patients with malignant ovarian tumors, and the correlation between vimentin expression and tumor stroma characteristics. MATERIAL AND METHODS: The study focused on 94 malignant ovarian tumors that had been collected from women who were treated in the Department of Gynecology and Oncology of the Lukaszczyk Oncological Center, Bydgoszcz, Poland. Vimentin expression was assessed in both the cancer cells (expression intensity and quantitative analysis) and the tumor stroma (expression intensity). Vimentin expression was analyzed according to both stromal cellularity and the clinicopatho- logical features of the disease. RESULTS: Both high cancer cell vimentin expression intensity and high quantitative vimentin expression (up to and includ- ing 30% of cells) indicated a significantly prolonged OS. Low vimentin stromal expression was associated with prolonged OS, although the difference did not reach the level of significance. High tumor cell vimentin expression intensity was as- sociated with significantly higher vimentin stromal expression. High vimentin expression in the tumor stroma indicated a significantly higher cellularity of the tumor stroma. Vimentin expression in cancer cells and the tumor stroma were not dependent on the histopathological type, the tumor grade or the FIGO stageof the disease. CONCLUSIONS: High cancer cell vimentin expression is associated with an improved OS of patients with malignant ovar- ian tumors. The expression of vimentin in ovarian malignancies may influence the structure of the tumor stroma.

Diagnosis and treatment of early gastric cancer: experience of one center.

INTRODUCTION: Gastric cancer is one of the most common malignant neoplasms in the world. Currently it constitutes the third cause of death among all malignancies. New endoscopic techniques have a potential to improve treatment results due to more frequent detection of early gastric cancer. AIM: To summarize our experience in diagnosis and treatment of early gastric cancer patients. MATERIAL AND METHODS: We analyzed the results of endoscopic examination, histopathological findings and treatment methods in 16 patients who were diagnosed with early gastric cancer in the Endoscopy Unit of the Oncology Center in Bydgoszcz between 2014 and 2016. RESULTS: Between 2014 and 2016 sixteen patients, 12 (75.0%) male and 4 (25.0%) female, were diagnosed with early gastric cancer. The average age of patients was 65.5 years. Surgery qualification concerned mainly G2 and G3 adenocarcinomas. In 12 (75.0%) patients total gastrectomy was performed, and 1 patient underwent wedge resection of the prepyloric part of the stomach. In 3 cases endoscopic submucosal dissection (ESD) was performed. Histopathological examination of both biopsy and postoperative material indicated 8 (50.0%) cases of intestinal-type adenocarcinoma, 7 (43.75%) cases of diffuse-type adenocarcinoma and 1 (6.25%) case of mixed-type adenocarcinoma. During the follow-up after treatment, none of the patients was diagnosed with local or distant recurrence. CONCLUSIONS: Accurate examination technique allows for detection of early gastric cancer. Selected cases of early gastric cancer may be treated with advanced endoscopic techniques.

On the role of classical and novel forms of vitamin D in melanoma progression and management.

Melanoma represents a significant clinical problem affecting a large segment of the population with a relatively high incidence and mortality rate. Ultraviolet radiation (UVR) is an important etiological factor in malignant transformation of melanocytes and melanoma development. UVB, while being a full carcinogen in melanomagenesis, is also necessary for the cutaneous production of vitamin D3 (D3). Calcitriol (1,25(OH)2D3) and novel CYP11A1-derived hydroxyderivatives of D3 show anti-melanoma activities and protective properties against damage induced by UVB. The former activities include inhibitory effects on proliferation, plating efficiency and anchorage-independent growth of cultured human and rodent melanomas in vitro, as well as the in vivo inhibition of tumor growth by 20(OH)D3 after injection of human melanoma cells into immunodeficient mice. The literature indicates that low levels of 25(OH)D3 are associated with more advanced melanomas and reduced patient survivals, while single nucleotide polymorphisms of the vitamin D receptor or the D3 binding protein gene affect development or progression of melanoma, or disease outcome. An inverse correlation of VDR and CYP27B1 expression with melanoma progression has been found, with low or undetectable levels of these proteins being associated with poor disease outcomes. Unexpectedly, increased expression of CYP24A1 was associated with better melanoma prognosis. In addition, decreased expression of retinoic acid orphan receptors α and γ, which can also bind vitamin D3 hydroxyderivatives, showed positive association with melanoma progression and shorter disease-free and overall survival. Thus, inadequate levels of biologically active forms of D3 and disturbances in expression of the target receptors, or D3 activating or inactivating enzymes, can affect melanomagenesis and disease progression. We therefore propose that inclusion of vitamin D into melanoma management should be beneficial for patients, at least as an adjuvant approach. The presence of multiple hydroxyderivatives of D3 in skin that show anti-melanoma activity in experimental models and which may act on alternative receptors, will be a future consideration when planning which forms of vitamin D to use for melanoma therapy.

Vitamin D signaling and melanoma: role of vitamin D and its receptors in melanoma progression and management.

Ultraviolet B (UVB), in addition to having carcinogenic activity, is required for the production of vitamin D3 (D3) in the skin which supplies >90% of the body's requirement. Vitamin D is activated through hydroxylation by 25-hydroxylases (CYP2R1 or CYP27A1) and 1α-hydroxylase (CYP27B1) to produce 1,25(OH)2D3, or through the action of CYP11A1 to produce mono-di- and trihydroxy-D3 products that can be further modified by CYP27B1, CYP27A1, and CYP24A1. The active forms of D3, in addition to regulating calcium metabolism, exert pleiotropic activities, which include anticarcinogenic and anti-melanoma effects in experimental models, with photoprotection against UVB-induced damage. These diverse effects are mediated through an interaction with the vitamin D receptor (VDR) and/or as most recently demonstrated through action on retinoic acid orphan receptors (ROR)α and RORγ. With respect to melanoma, low levels of 25(OH)D are associated with thicker tumors and reduced patient survival. Furthermore, single-nucleotide polymorphisms of VDR and the vitamin D-binding protein (VDP) genes affect melanomagenesis or disease outcome. Clinicopathological analyses have shown positive correlation between low or undetectable expression of VDR and/or CYP27B1 in melanoma with tumor progression and shorter overall (OS) and disease-free survival (DFS) times. Paradoxically, this correlation was reversed for CYP24A1 (inactivating 24-hydroxylase), indicating that this enzyme, while inactivating 1,25(OH)2D3, can activate other forms of D3 that are products of the non-canonical pathway initiated by CYP11A1. An inverse correlation has been found between the levels of RORα and RORγ expression and melanoma progression and disease outcome. Therefore, we propose that defects in vitamin D signaling including D3 activation/inactivation, and the expression and activity of the corresponding receptors, affect melanoma progression and the outcome of the disease. The existence of multiple bioactive forms of D3 and alternative receptors affecting the behavior of melanoma should be taken into consideration when applying vitamin D management for melanoma therapy.

RORα and RORγ expression inversely correlates with human melanoma progression.

The retinoic acid-related orphan receptors (RORs) regulate several physiological and pathological processes, including immune functions, development and cancer. To study the potential role of RORs in melanoma progression, we analysed RORα and RORγ expression in nevi and primary melanomas and non-lesional skin and metastases in relation to melanoma clinico-pathomorphological features. The expression of RORα and RORγ was lower in melanomas than in nevi and decreased during melanoma progression, with lowest levels found in primary melanomas at stages III and IV and in melanoma metastases. Their expression correlated with pathomorphological pTNM parameters being low in aggressive tumors and being high in tumors showing histological markers of good prognosis. Higher nuclear levels of RORα and RORγ and of cytoplasmic RORγ correlated with significantly longer overall and disease free survival time. Highly pigmented melanomas showed significantly lower level of nuclear RORs. This study shows that human melanoma development and aggressiveness is associated with decreased expression of RORα and RORγ, suggesting that RORs could be important in melanoma progression and host responses against the tumor. Furthermore, it suggests that RORα and RORγ might constitute a novel druggable target in anti-melanoma management using tumor suppressor gene therapy restoring their normal functions.

Changes in Immunogenicity during the Development of Urinary Bladder Cancer: A Preliminary Study.

In the present study, we evaluated tumor-infiltrating lymphocytes (TILs) and blood regulatory T lymphocyte (Tregs, CD4+/CD25+/FoxP3+) expression in bladder cancer patients. The number of CD4+, CD8+, CD25+, FoxP3+ and CD20+ TILs was analyzed in association with clinico-pathomorphological features. In more advanced metastasizing tumors, showing non-classic differentiation (ND) and a more aggressive tissue invasion type (TIT), the number of TILs decreased. A low number of CD4+ TILs was associated with poor prognosis. Similarly, Treg frequency before surgery and after surgical treatment was significantly lower in more advanced tumors. The changes in TILs, as well as of local and systemic Tregs, were accompanied by changes in the histological phenotype of urothelial carcinoma regarding pT stage, NDs, TIT, and clinical outcomes. The number of TILs and the frequency of blood Tregs (indicators of antitumor response) may be essential for choosing an immunotherapy that is adjusted to the immune status according to the phase of tumor growth. Moreover, a significant reduction in the number of CD4+ and CD8+ TILs with the development of NDs in more advanced tumors may be associated with lower tumor immunogenicity, resulting in immune tolerance towards tumor tissue. These observations and the tendency of urothelial bladder carcinoma to undergo NDs in a heterogeneous manner during tumor progression suggest complex interactions between bladder cancer immunogenicity and stages of tumor progression.

Melanin content in melanoma metastases affects the outcome of radiotherapy.

Melanin possess radioprotective and scavenging properties, and its presence can affect the behavior of melanoma cells, its surrounding environment and susceptibility to the therapy, as showed in vitro experiments. To determine whether melanin presence in melanoma affects the efficiency of radiotherapy (RTH) we evaluated the survival time after RTH treatment in metastatic melanoma patients (n = 57). In another cohort of melanoma patients (n = 84), the relationship between melanin level and pT and pN status was determined. A significantly longer survival time was found in patients with amelanotic metastatic melanomas in comparison to the melanotic ones, who were treated with either RTH or chemotherapy (CHTH) and RTH. These differences were more significant in a group of melanoma patients treated only with RTH. A detailed analysis of primary melanomas revealed that melanin levels were significantly higher in melanoma cells invading reticular dermis than the papillary dermis. A significant reduction of melanin pigmentation in pT3 and pT4 melanomas in comparison to pT1 and T2 tumors was observed. However, melanin levels measured in pT3-pT4 melanomas developing metastases (pN1-3, pM1) were higher than in pN0 and pM0 cases. The presence of melanin in metastatic melanoma cells decreases the outcome of radiotherapy, and melanin synthesis is related to higher disease advancement. Based on our previous cell-based and clinical research and present research we also suggest that inhibition of melanogenesis can improve radiotherapy modalities. The mechanism of relationship between melanogenesis and efficacy of RTH requires additional studies, including larger melanoma patients population and orthotopic, imageable mouse models of metastatic melanoma.

Frequency of CD4+CD25+Foxp3+ cells in peripheral blood in relation to urinary bladder cancer malignancy indicators before and after surgical removal.

Tumor cells communicate with stromal cells, including cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs), to form microenvironment inhibiting immune responses. Regulatory T cells (Tregs, CD4+CD25+FoxP3+) stimulate immune tolerance and facilitate tumor progression. We analyzed the changes in Treg frequencies assessed using flow cytometry in the peripheral blood of patients with urothelial bladder cancer before and after tumor-removal. Changes in Treg frequency were investigated in relation to clinicopathomorphological indicators of tumor malignancy and expression of RCAS1 on CAFs and TAMs. Higher Treg frequencies were observed in early phase of tumor growth (pTa-pT2), in larger tumors, with more aggressive type of invasion, and with expression of RCAS1. The later phase of tumor development, accompanied by a nonclassic differentiations and pT3-pT4 advancement, had lower number of tumor infiltrating lymphocytes (TILs) and lower Treg frequency. Furthermore, in pT2-pT4 tumors, a decreased post-surgery Treg frequency was associated with poorer prognosis: patients with the lowest frequency of Tregs died first. These findings strongly suggest that the Treg frequencies at later phase of tumor growth, associated with a low anti-tumor response, represent a new and important prognostic indicator in urinary bladder cancer.

Expression of Vitamin D Receptor (VDR) Positively Correlates with Survival of Urothelial Bladder Cancer Patients.

Vitamin D3 shows tumoristatic and anticancer effects by acting through the vitamin D receptor (VDR), while hydroxylation of 25-hydroxyvitamin D3 at position 1α by CYP27B1 is an essential step in its activation. The expression of both the VDR and CYP27B1 has been found in many normal and cancer tissues, but there is a lack of information about its expression in human bladder cancers. The aim of the present research was to examine whether the expression of the VDR and CYP27B1 in bladder cancer was related to the prognostic markers and disease outcome. We analyzed VDR and CYP27B1 in samples of tumor and normal tissues obtained from 71 urinary bladder cancer patients. The highest VDR immunostaining was found in normal epithelium and was significantly lower in bladder cancer cells (p<0.001 with Mann-Whitney U test). VDR expression was lowest in more advanced (pT2b-pT4) (p=0.005 with Mann-Whitney U test) and metastasizing cancers (p<0.05 and p=0.004 with Mann-Whitney U test for nuclear and cytoplasmic VDR immunostaining, respectively). The lack of cytoplasmic and nuclear VDR was also related to shorter overall survival (for cytoplasmic VDR immunolocalization 13.3 vs. 55.3 months of survival, HR=1.92, p=0.04 and for nuclear VDR immunostaining 13.5 vs. 55.3 months of survival, HR=2.47, p=0.002 with Mantel-Cox test). In cases with the lack of high cytoplasmic VDR staining the non-classic differentiations (NDs) was observed in higher percentage of tumor area. CYP27B1 expression was lower in cancer cells than in normal epithelial cells (p=0.03 with Mann-Whitney U test), but its expression did not correlate with tumor stage (pT), metastasizing, grade, mitotic activity or overall survival. In conclusion, expression of the VDR and CYP27B1 are deregulated in urothelial bladder cancers. Although our results showing a relationship between the decreased VDR expression and prognostic markers and survival time indicate potential usefulness of VDR as a new indicator of a poorer prognosis, further studies are needed in different patient cohorts by independent groups to validate this hypothesis. We also suggest that vitamin D-based therapies may represent an adjuvant strategy in treatment for bladder cancers expressing VDR.

Transdifferentiation of Bone Marrow Mesenchymal Stem Cells into the Islet-Like Cells: the Role of Extracellular Matrix Proteins.

Pancreatic islet implantation has been recently shown to be an efficient method of treatment for type 1 diabetes. However, limited availability of donor islets reduces its use. Bone morrow would provide potentially unlimited source of stem cells for generation of insulin-producing cells. This study was performed to evaluate the influence of extracellular matrix proteins like collagen, laminin, and vitronectin on bone marrow mesenchymal stem cells (BM-MSCs) transdifferentiation into islet-like cells (ILCs) in vitro. To our knowledge, this is the first report evaluating the importance of vitronectin in transdifferentiation of BM-MSCs into ILCs. Rat BM-MSCs were induced to ILCs using four-step protocol on plates coated with collagen type IV, laminin type I and vitronectin type I. Quantitative real-time PCR was performed to detect gene expression related to pancreatic ß cell development. The induced cells expressed islet-related genes including: neurogenin 3, neurogenic differentiation 1, paired box 4, NK homeobox factor 6.1, glucagon, insulin 1 and insulin 2. Laminin but not collagen type IV or vitronectin enhanced expression of insulin and promoted formation of islet-like structures in monolayer culture. Laminin triggered transdifferentiation of BM-MSCs into ILCs.