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Marika Musielak,1– 3 Agnieszka Boś-Liedke,4 Oliwia Piwocka,1– 3 Katarzyna Kowalska,5 Roksana Markiewicz,6 Aleksandra Lorenz,7 Paweł Bakun,2,8 Wiktoria Suchorska1,3 1Department of Electroradiology, Poznan University of Medical Sciences, Poznan, Poland; 2Doctoral School, Poznan University of Medical Sciences, Poznan, Poland; 3Radiobiology Laboratory, Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland; 4Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland; 5Department of Histology and Embryology, Poznan University of Medical Sciences, Poznan, Poland; 6NanoBioMedical Centre, Adam Mickiewicz University, Poznan, Poland; 7Faculty of Agronomy, Horticulture and Bioengineering, Poznan University of Life Sciences, Poznan, Poland; 8Chair and Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Poznan, PolandCorrespondence: Marika Musielak, Department of Electroradiology, Poznan University of Medical Sciences, Garbary 15, Poznan, 61-866, Poland, Tel +48505372 290, Email marikamusielak@gmail.comPurpose: Breast cancer (BC) is the most common malignant tumor in women, which most often originates from the epithelial tissue of the breast gland. One of the most recommended kinds of treatment is radiotherapy (RT), but irradiation (IR) can affect not only the cancer tumor but also the healthy tissue around it. Au nanoparticles (AuNPs) were proposed as a radiosensitizing agent for RT which would allow for lower radiation doses, reducing the negative radiation effects on healthy tissues. The main objective of the study is to assess the dependence on the radiosensitivity of BC (MDA-MB-231) and normal mammary gland epithelial cells (MCF12A) to ionizing radiation, caused by functionalized AuNPs under diverse conditions.Methods: The viability, uptake, reactive oxygen species induction, and mitochondrial membrane potential in cells were analyzed applying a time and concentration-dependent manner. After different incubation times with AuNPs, cells were exposed to 2 Gy. The determination of radiation effect in combination with AuNPs was investigated using the clonogenic assay, p53, and γH2AX level, as well as, Annexin V staining.Results: Our results highlighted the strong need for assessing the experimental conditions’ optimization before the AuNPs will be implemented with IR. Moreover, results indicated that AuNPs did not act universally in cells.Conclusion: AuNPs could be a promising tool as a radiotherapy sensitizing agent, but it should be specified and deeply investigated under what conditions it will be applied taking into consideration not only AuNPs modifications but also the model and experimental conditions.Keywords: oncology, nanotechnology, nanoparticles, radiotherapy, breast cancer

The aim of the study was to evaluate the changes in γ-H2AX expression in peripheral blood lymphocytes (PBL) according to severity of radiation-induced mucositis.

Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

Background. Efficient stem cell differentiation is considered to be the holy grail of regenerative medicine. Pursuing the most productive method of directed differentiation has been the subject of numerous studies, resulting in the development of many effective protocols. However, the necessity for further improvement in differentiation efficiency remains. This review contains a description of molecular processes underlying the response of stem cells to ionizing radiation, indicating its potential application in differentiation procedures. In the first part, the radiation-induced damage response in various types of stem cells is described. Second, the role of the p53 protein in embryonic and adult stem cells is highlighted. Last, the hypothesis on the mitochondrial involvement in stem cell development including its response to ionizing radiation is presented.

Cartilage tissue, characterized by its limited regenerative capacity, presents significant challenges in clinical therapy. Recent advancements in cartilage regeneration have focused on integrating stem cell therapies, tissue engineering strategies, and advanced modeling techniques to overcome existing limitations. Stem cells, particularly Mesenchymal Stem Cells (MSCs) and induced pluripotent stem cells (iPSCs), hold promise for cartilage repair due to their ability to differentiate into chondrocytes, the key cells responsible for cartilage formation. Tissue engineering approaches, including 3D models, organ-on-a-chip systems, and organoids, offer innovative methods to mimic natural tissue microenvironments and evaluate potential treatments. MSC-based techniques, such as cell sheet tissue engineering, address challenges associated with traditional therapies, including cell availability and culture difficulties. Furthermore, advancements in 3D bioprinting enable the fabrication of complex tissue structures, while organ-on-a-chip systems provide microfluidic platforms for disease modeling and physiological mimicry. Organoids serve as simplified models of organs, capturing some complexity and enabling the monitoring of pathophysiological aspects of cartilage diseases. This comprehensive review underscores the transformative potential of integrating stem cell therapies, tissue engineering strategies, and advanced modeling techniques to improve cartilage regeneration and pave the way for more effective clinical treatments., Competing Interests: Authors declare no conflict of interest., (Copyright © 2024 Skoracka et al.)

Purpose: Breast cancer is a complex disease with several molecular subtypes that respond differently to therapy. This paper describes liposomes loaded with gold nanoparticles as a targeted drug delivery method in the rapidly developing precision breast cancer treatment area. The aim was to investigate the cytotoxicity level and cellular uptake using several breast cancer cell lines and a normal breast cell line., Materials and Methods: We synthesized gold nanoparticles incorporated in liposomes. Nanostructures were incubated with breast cancer cell lines of different subtypes. The analysis included MTT assay, flow cytometry and immunofluorescence., Results: Cell viability varied among different cancer cells. Moreover, the time- and concentration-dependent manner of viability change was observed. The internalization of liposomes with gold nanoparticles and nanoparticles alone determined different results depending on molecular breast cancer subtypes. The luminal B and triple-negative breast cancer cells demonstrated the highest resistance and sensitivity, respectively. The intensity of cells' interaction with the proposed nanostructures was observed in both cell lines. In this study, we compare the molecular subtypes of breast cancer and discuss how this novel method might improve the therapy success., Conclusions: Our research sheds light on the possibility of new individualized treatments for breast cancer patients, opening the path for better results and a more detailed cancer therapy strategy., Competing Interests: Declaration of competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Hypo-fractionated stereotactic body radiation therapy (SBRT) is an effective treatment for prostate cancer (PCa). Although many studies have investigated the effects of SBRT on the prostate and adjacent organs, little is known about the effects further out-of-field. The aim of this study was to investigate, both in vitro and in a quasi-humanoid phantom, the biological effects (using a dose-scaling approach) of radiation in the out-of-field peripheral organs delivered by 6 MV volumetric modulated arc therapy (VMAT) SBRT in a prostate cancer model. Healthy prostate cells were irradiated in a phantom at locations corresponding to the prostate, intestine, lung, thyroid, and brain. Seven 10 Gy fractions of VMAT SBRT were delivered to the target in a single session without intermission (scaled-up method). Radiochromic films were used to measure the doses. The radiobiological response was assessed by measuring DNA breaks, the cell survival fraction, and differences in gene expression profile. Our results showed a strong, multiparametric radiobiological response of the cells in the prostate. Outside of the radiation field, the highest doses were observed in the intestine and lung. A small increase (not statistically significant) in DNA damage and cell death was observed in the intestines. Several gene groups (cell cycle, DNA replication) were depleted in the lung and thyroid (DNA replication, endocytosis), but further analysis revealed no changes in the relevant biological processes. This study provides extensive evidence of the types and extent of radiobiological responses during VMAT SBRT in a prostate cancer model. Additional research is needed to determine whether the radiobiological effects observed in the peripheral organs are validated in a clinical context.

The aim of the study was to determine the influence of a key treatment plan and beam parameters on overall dose distribution and on doses in organs laying in further distance from the target during prostate SBRT. Multiple representative treatment plans (n = 12) for TrueBeam and CyberKnife were prepared and evaluated. Nontarget doses were measured with anionization chamber, in a quasi-humanoid phantom at four sites corresponding to the intestines, right lung, thyroid, and head. The following parameters were modified: radiotherapy technique, presence or not of a flattening filter, degree of modulation, and use or not of jaw tracking function for TrueBeam and beam orientation set-up, optimization techniques, and number of MUs for CyberKnife. After usual optimization doses in intestines (near the target) were 0.73% and 0.76%, in head (farthest from target) 0.05% and 0.19% for TrueBeam and CyberKnife, respectively. For TrueBeam the highest peripheral (head, thyroid, lung) doses occurred for the VMAT with the flattening filter while the lowest for 3DCRT. For CyberKnife the highest doses were for gantry with caudal direction beams blocked (gantry close to OARs) while the lowest was the low modulated VOLO optimization technique. The easiest method to reduce peripheral doses was to combine FFF with jaw tracking and reducing monitor units at TrueBeam and to avoid gantry position close to OARs together with reduction of monitor units at CyberKnife, respectively. The presented strategies allowed to significantly reduce out-of-field and nontarget doses during prostate radiotherapy delivered with TrueBeam and CyberKnife. A different approach was required to reduce peripheral doses because of the difference in dose delivery techniques: non-coplanar using CyberKnife and coplanar using TrueBeam, respectively.

Our understanding of low dose, out-of-field radiation and their radiobiological effects are limited, in part due to the rapid technological advances in external beam radiotherapy, especially for non-coplanar and dynamic techniques. Reliable comparisons of out-of-field doses produced by advanced radiotherapy techniques are difficult due to the limitations of commercially available phantoms. There is a clear need for a functional phantom to accurately measure the dosimetric and radiobiological characteristics of out-of-field doses, which would in turn allow clinicians and medical physicists to optimize treatment parameters. We designed, manufactured, and tested the performance of a quasi-humanoid (Q-H) adult phantom. To test the physics parameters, we used computed tomography (CT) scans of assembled Q-H phantom. Static open field and dynamic techniques were measured both in- and out-of-field with ionization chambers and radiochromic films for two configurations (full solid and with water-filled containers). In the areas simulating soft tissues, lung, and bones, median Hounsfield units and densities were, respectively: 129.8, -738.7, 920.8 HU and 1.110, 0.215, 1.669 g/cm 3 . Comparison of the measured to treatment planning systems (TPS) in-field dose values for the sample volumetric arc therapy (VMAT) (6 MV flattening filter-free (FFF)) plan, 96.4% of analyzed points passed the gamma evaluation criteria (L2%/2 mm, threshold (TH) 10%) and less than 1.50% for point dose verification. In the two phantom configurations: full poly(methyl) methacrylate (PMMA) and with water container, the off-axis median doses for open field, relative to the central axis of the beam (CAX) were similar, respectively: 0.900% versus 0.907% (15 cm distance to CAX); 0.096% versus 0.120% (35 cm); 0.018% versus 0.018% (52 cm); 0.009% versus 0.008% (74 cm). For VMAT 6 MV FFF, doses relative the CAX were, respectively: 0.667% (15 cm), 0.062% (35 cm), 0.019% (52 cm), 0.016% (74 cm). The Q-H phantom meets the International Commission on Radiation Units and Measurements (ICRU) and American Association of Physicists in Medicine (AAPM) recommended phantom criteria, providing medical physicists with a reliable, comprehensive system to perform dose calculation and measurements and to assess the impact on radiobiological response and on the risk of secondary tumor induction., (© 2022 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.)

Background: Due to the lack of selectivity of ionizing radiation between normal and cancer cells, it is important to improve the existing radiation patterns. Lowering the risk of cancer recurrence and comfort during treatment are priorities in radiotherapy., Materials and Methods: In the experiment we used dose verification to determine the irradiation time calculated by a treatment planning system for 6XFFF and 10XFFF beams. Cells cultured under standard conditions were irradiated with a dose of 2 Gy at different beam rates 400 MU/min, 600 MU/min, 800 MU/min, 1000 MU/min, 1400 MU/min, 1600 MU/min and 2400 MU/min using 6XFFF, 10XFFF and 6XFF beams., Results: The experiment was aimed at comparing the biological response of normal prostate cells after clinically applied radiation patterns. No statistically significant differences in the cellular response were observed. The wide range of beam rates as well as the beam profiles did not significantly affect cell proliferation., Conclusions: High beam rates, without significantly affecting the clonogenic capacity of cells, have an impact on the quality of patient's treatment. With the increasing beam rate the irradiation time is shortened, which has an important impact on patients' health. This experiment can have a practical significance., Competing Interests: Conflict of interest No conflict of interest, (© 2021 Greater Poland Cancer Centre.)

To increase the efficiency of therapy via enhancing its selectivity, the usage of gold nanorods (GNR) as a factor sensitizing cancer cells to radiation was proposed. Due to gold nanoparticles' characteristics, the smaller doses of radiation would be sufficient in the treatment, protecting the healthy tissue around the tumor. The aim of this study was to investigate the effect of gold nanorods on cancer and normal prostate cells and the role of nanorods in the cell response to ionizing radiation. The effect was evaluated by measuring the toxicity, cell cycle, cell granularity, reactive oxygen species (ROS) level, and survival fractions. Nanorods showed a strong toxicity dependent on the concentration and incubation time toward all used cell lines. A slight effect of nanorods on the cycle distribution was observed. The results demonstrated that the administration of nanorods at higher concentrations resulted in an increased level of generated radicals. The results of cellular proliferation after irradiation are ambiguous; however, there are noticeable differences after the application of nanorods before irradiation. The obtained results lead to the conclusion that nanorods affect the physiology of both normal and cancer cells. Nanorods might become a potential tool used to increase the effectiveness of radiation treatment.

Adropin is a multifunctional peptide hormone encoded by the ENHO (energy homeostasis associated) gene. It plays a role in mechanisms related to increased adiposity, insulin resistance, as well as glucose, and lipid metabolism. The low adropin levels are strongly associated with obesity independent insulin resistance. On the other hand, overexpression or exogenous administration of adropin improves glucose homeostasis. The multidirectional, adropin-related effects associated with the regulation of metabolism in humans also appear to be attributable to the effects of this peptide on the activity of various elements of the endocrine system including adrenal cortex. Therefore, the main purpose of the present study was to investigate the effect of adropin on proliferation and secretory activity in the human HAC15 adrenal carcinoma cell line. In this study, we obtained several highly interesting findings. First, GPR19, the main candidate sensitizer of adrenocortical cells to adropin, was expressed in HAC15 cells. Moreover, GPR19 expression was relatively stable and not regulated by ACTH, forskolin, or adropin itself. Our findings also suggest that adropin has the capacity to decrease expression levels of steroidogenic genes such as steroidogenic acute regulatory protein ( StAR ) and CYP11A1 , which then led to a statistically significant inhibition in cortisol and aldosterone biosynthesis and secretion. Based on whole transcriptome study and research involving transforming growth factor (TGF)-β type I receptor kinase inhibitor we demonstrated that attenuation of steroidogenesis caused by adropin is mediated by the TGF-β signaling pathway likely to act through transactivation mechanism. We found that HAC15 cells treated with adropin presented significantly higher proliferation levels than untreated cells. Using specific intracellular inhibitors, we showed that adropin stimulate proliferation via ERK1/2 and AKT dependent signaling pathways. We have also demonstrated that expression of GPR19 is elevated in adrenocortical carcinoma in relation to normal adrenal glands. High level of GPR19 expression in adrenocortical carcinoma may constitute a negative prognostic factor of disease progression., (Copyright © 2020 Stelcer, Milecka, Komarowska, Jopek, Tyczewska, Szyszka, Lesniczak, Suchorska, Bekova, Szczepaniak, Ruchala, Karczewski, Wierzbicki, Szaflarski, Malendowicz and Rucinski.)

Tumor-promoting inflammation is one of the hallmarks of cancer. It has been shown that cancer development is strongly influenced by both chronic and acute inflammation process. Progress in research on inflammation revealed a connection between inflammatory processes and neoplastic transformation, the progression of tumour, and the development of metastases and recurrences. Moreover, the tumour invasive procedures (both surgery and biopsy) affect the remaining tumour cells by increasing their survival, proliferation and migration. One of the concepts explaining this phenomena is an induction of a wound healing response. While in normal tissue it is necessary for tissue repair, in tumour tissue, induction of adaptive and innate immune response related to wound healing, stimulates tumour cell survival, angiogenesis and extravasation of circulating tumour cells. It has become evident that certain types of immune response and immune cells can promote tumour progression more than others. In this review, we focus on current knowledge on carcinogenesis and promotion of cancer growth induced by inflammatory processes., (© 2020 The Author(s).)

Breast cancer is the most common cancer occurring in women. The standard of breast cancer treatment is based on breast-conserving surgery with administration of adjuvant whole breast radiotherapy. Research shows that in-breast relapse is most likely to occur in the tumour bed, i.e. around the scar. Intraoperative radiotherapy (IORT), in which radiation is delivered to the tumour bed, reduces the risk of local recurrence not only through direct cell killing, but also through modification of local microenvironment. Additionally IORT modifies the composition and biological activity of surgical wound fluid. Since many researchers show that radiation damage is mediated through factors secreted to the environment by irradiated cells, we hypothesized that this radiation-induced bystander effect is partly responsible for the change observed in surgical wound fluids. We collected conditioned medium from irradiated breast cancer cells (CM) and surgical wound fluids from patients who underwent IORT (RT-WF) and from patients after breast-conserving surgery alone (WF). We incubated two breast cancer cell lines (MCF-7 and MDA-MB-468) with WF, RT-WF, CM or WF + CM and measured radiobiological response of cells. We measured the level of double-strand breaks, induction of apoptosis and the changes in expression of genes related to DNA damage repair. We observed that stimulation with RT-WF and with WF + CM-induced double-strand breaks and increased expression of DNA damage repair-related genes, which was not observed after stimulation with WF. These results suggest that IOERT induces secretion of bystander factors mediating the genotoxic effect of ionizing radiation.

Head and neck cancer is characterized by malignant tumors arising from the epithelium covering the upper aerodigestive tract, and the majority of these epithelial malignancies are squamous cell carcinomas (SCCs) of the oral cavity (OSCCs). The aim of the current work was to identify miRNAs regulated in OSCC cancerous tissue when compared to a healthy adjacent tissue and to verify the presence of the same miRNAs in the circulation of these patients. For that serum samples and biopsies of healthy and tumor tissues were collected from five patients diagnosed with OSCC of the oral cavity, RNA was extracted from these samples and microRNAs libraries were prepared and sequenced. A total 255 miRNAs were identified in tissue and 381 different miRNAs were identified in serum samples. When comparing the miRNA expression between tumor and healthy tissue we identified 48 miRNAs (25 down- and 23 up-regulated) that were differentially expressed (FDR < 0.05). From these 48 differentially expressed miRNAs in tissue, 30 miRNAs were also found in the serum of the same patients. hsa-miR-32-5p was up-regulated in tumor compared to healthy tissue in our study, and was previously shown to be up-regulated in the serum of OSCC patients. Therefore, this suggests that miRNAs can be used as potential non-invasive biomarkers of OSCC.

Breast cancer is the most common malignant disease occurring in women. Conservative breast cancer surgery followed by radiation therapy is currently the standard treatment for this type of cancer. The majority of metastases occur within the scar, which initiated a series of studies. As a result, clinical trials aimed to assess whether localized radiotherapy, as intraoperative radiotherapy (IORT), may more effective in inhibiting the formation of local recurrence compared with the standard postoperative whole breast radiotherapy. The present study determined the role of postoperative wound fluids (WFs) from patients diagnosed with breast cancer subsequent to breast conserving surgery or breast conserving surgery followed by IORT on the expression of three microRNAs (miRNAs), consisting of miR-21, miR-155 and miR-221, in distinct breast cancer cell lines that represent the general subtypes of breast cancer. It was determined that the miRNAs responsible for breast cancer progression, induction of tumorigenesis and enrichment of the cancer stem cell phenotype, which is responsible for resistance to tumor therapy, were highly upregulated in the human epidermal growth factor receptor 2-positive breast cancer SK-BR-3 cell line following stimulation with WFs. It is worth emphasizing, that those changes were more significant in WFs collected from patients after surgery alone. The BT-549 cell line showed altered expression only of miR-155 following incubation with WFs. Notably, this change was not associated with IORT. Additionally, it was indicated that both WFs and RT-WF strongly downregulated the expression of miR-21, miR-155 and miR-221 in basal/epithelial and luminal subtypes of breast cancer. It was concluded that the present study contributes to an increased understanding of the role of surgical WFs and IORT treatment in the regulation of miRNA expression. This may enable the development of the current knowledge of breast cancer biology subsequent to IORT treatment and substantially to improve the therapy in the future.

Purpose: Patients who undergo external beam radiotherapy are at risk of developing second tumours due to scattered radiation outside the path of the primary beam. The aim of this study was to experimentally determine the in vitro radiobiological effects of scattered radiation in cells located outside the primary photon beam and to compare this to the effects that occur in cells inside the primary beam. The comparison was performed by assessing cell viability, DNA damage, and apoptosis., Material and Methods: Cells from the human breast cancer line MDA-MB-231 were inserted in a water phantom and irradiated at varying doses (1.5, 2.0, 2.5, and 3.0Gy). The cells were placed at two geometrical points: in the central beam axis and at 10cm out-of-field. The dose was constant in both geometrical points. Survival fraction, number of DNA double strand-breaks, and cleaved poly-(ADP-ribose) polymerase (PARP) levels were determined by clonogenic assay and flow cytometry., Results: A slight, non-significant decrease of 3 to 5% in cell survival fraction was observed in cells irradiated outside the primary field. The number of PARP-positive cells and DNA double strand-breaks both increased after out-of-field irradiation., Conclusion: Scattered irradiation appears to induce an in vitro biological response on out-of-field cells that is stronger than the effect of primary radiation on in-field cells, independent of the bystander effect. These findings suggest that the biological response of healthy tissues outside the primary beam might be higher than previously believed., (Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

Purpose: The study was designed to investigate whether serum concentrations of leptin, resistin and adiponectin in obese and normal-weight patients with primary knee osteoarthritis (OA) correlate with clinical and radiological stages of the disease and percentage of total body fat., Methods: Seventy-three patients with knee OA, divided into obese and normal-weight groups, were clinically evaluated according to the Knee Society Score (KSS), and radiologically assessed using Kellgren and Lawrence scale. The percentage of total body fat and some anthropometric data were also given. Serum leptin, resistin and adiponectin concentrations were measured by Elisa and were correlated with the clinical, radiological and anthropometric parameters., Results: Leptin concentrations were significantly higher (p = 0.001) in the obese patients and positively correlated (R = 0.63) with radiologically assessed OA grade, but only in the normal-weight group. Resistin and adiponectin concentrations were identical in obese and normal-weight patients and negatively correlated (R = -0.41) with the clinical status of obese patients. In both groups, percentage of total body fat positively correlated (R = 0.29 and R = 0.53 for obese and normal-weight respectively) with radiologically assessed OA grade. However, no correlations were found with clinical status of the patients., Conclusions: It was found that in the obese patients with knee OA, increased percentage of total body fat and elevated serum leptin concentration might favour the advancement of clinical but not radiologically assessed changes in the joint structures, while in normal-weight patients it correlates only with radiologically assessed changes but does not affect to an appreciable extent the clinical status of the patients.

Conservative breast cancer surgery followed by radiation therapy is the standard treatment for this type of cancer. Numerous studies demonstrate that 90% of local recurrences after traditional surgery occur in the same quadrant as the primary cancer. The published data suggest that the wound healing process after surgery alters the area surrounding the original tumor and the modified microenvironment is more favorable for the tumor to recur. The majority of metastases within scar initiated much research, and the consequences of these studies led to clinical trials aimed at assessing whether localized radiotherapy, such as intraoperative radiotherapy (IORT), would be more effective in inhibiting formation of local recurrence than the standard postoperative whole breast radiotherapy. IORT involves irradiation of diseased tissue directly during surgery. The rationale for this approach is the fact that the increase in the radiation dose increases local tumor control, which is the primary goal of radiation therapy. The biological basis of this process are still not thoroughly understood. Gaining new knowledge about the recurrence formation at the molecular level could serve as a starting point for further analysis and to create an opportunity to identify new targets of therapy, and possibly new therapeutic agents.

Over 20 years ago it was realized that the traditional methods of the treatment of injuries to joint components: cartilage, menisci and ligaments, did not give satisfactory results and so there is a need of employing novel, more effective therapeutic techniques. Recent advances in molecular biology, biotechnology and polymer science have led to both the experimental and clinical application of various cell types, adapting their culture conditions in order to ensure a directed differentiation of the cells into a desired cell type, and employing non-toxic and non-immunogenic biomaterial in the treatment of knee joint injuries. In the present review the current state of knowledge regarding novel cell sources, in vitro conditions of cell culture and major important biomaterials, both natural and synthetic, used in cartilage, meniscus and ligament repair by tissue engineering techniques are described, and the assets and drawbacks of their clinical application are critically evaluated.

Purpose: The use of stem cells in regenerative medicine offers hope to treat numerous orthopaedic disorders, including articular cartilage defects. Although much research has been carried out on chondrogenesis, this complicated process is still not well understood and much more research is needed. The present review provides an overview of the stages of chondrogenesis and describes the effects of various growth factors, which act during the multiple steps involved in stem cell-directed differentiation towards chondrocytes., Methods: The current literature on stem cell-directed chondrogenesis, in particular the role of members of the transforming growth factor-β (TGF-β) superfamily-TGF-βs, bone morphogenetic proteins (BMPs) and fibroblast growth factors (FGFs)-is reviewed and discussed., Results: Numerous studies have reported the chondrogenic potential of both adult- and embryonic-like stem cells and the role of growth factors in programming differentiation of these cells towards chondrocytes. Mesenchymal stem cells (MSCs) are adult multipotent stem cells, whereas induced pluripotent stem cells (iPSC) are reprogrammed pluripotent cells. Although better understanding of the processes involved in the development of cartilage tissues is necessary, both cell types may be of value in the clinical treatment of cartilage injuries or osteoarthritic cartilage lesions., Conclusions: MSCs and iPSCs both present unique characteristics. However, at present, it is still unclear which cell type is most suitable in the treatment of cartilage injuries.

Lentiviral vectors are efficient vehicles for stable gene transfer in both dividing and non-dividing cells. This feature among others makes lentiviral vectors a powerful tool in molecular research. However, the use of lentiviruses in research studies and clinical trials requires a precise and validated titration method. In this study, we describe a qPCR-based approach for estimation of lentiviral vector titer (pLV-THM-GFP). The use of WPRE (Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element) and albumin genes as templates for an SYBR green-based real-time qPCR method allows for a rapid, sensitive, reproducible, and accurate assessment of lentiviral copy number at an integrated lentiviral DNA level. Furthermore, this optimization enables measurement of lentiviral concentration even in very poor quality and small quantity material. Consequently, this approach provides researchers with a tool to perform low-cost assessment with highly repeatable results.

Purpose: Antitumor potential of angiotensin-converting enzyme inhibitors has been shown in different preclinical settings, which always involved immunocompromised organisms or nonimmunogenic tumor models. In our study, we wanted to evaluate the effect of captopril on growth of immunogenic tumors in immunocompetent animals., Experimental Design: We used different murine tumor models to evaluate the effect of captopril on tumor take and survival of tumor-bearing immunocompetent and immunocompromised mice. We used an orthotopic renal cell cancer model and highly immunogenic tumor model, which were based on kidney subcapsular injection of RenCa cells or s.c. injection of MethA cells, respectively. To show the influence of captopril on antigen-specific immune responses, we have used two model antigens (green fluorescent protein and beta-galactosidase)., Results: Captopril decreased survival of RenCa-bearing, immunocompetent mice in a dose-dependent manner and in adjuvant setting. In nephrectomized mice, captopril shortened their survival. Captopril promoted formation of immunogenic MethA sarcoma tumors but had no effect on nonimmunogenic melanoma cells (B78-H1). Treatment of immunocompromised mice bearing MethA tumors or RenCa kidney tumors with captopril did not affect tumor formation nor survival, respectively. Captopril-treated mice immunized with AdLacZ or AdGFP vectors did not generate or generated decreased numbers of antigen-specific CD8+ T cells, respectively. However, they showed B-cell responses represented by infiltration of MethA tumors with activated B cells and dramatically increased serum level of beta-galactosidase-specific antibodies., Conclusions: Our results show a novel role of captopril in tumor biology and the tumor-promoting properties of captopril seem to be associated with its immunomodulatory potential.