Stanisław Szala

• Cancer Center and Institute of Oncology

Due to immunosuppressive properties and confirmed tropism towards cancer cells mesenchymal stromal cells (MSC) have been used in many trials. In our study we used these cells as carriers of IL-12 in the treatment of mice with primary and metastatic B16-F10 melanomas. IL-12 has confirmed anti-cancer activity, induces a strong immune response against...

The tumor microenvironment is a pathological niche in which progression of cancer occurs. The microenvironment is created, among others, by cancer-specific fibroblasts (CAFs), endothelial cells of tumor blood vessels, and immune cells that inhibit the antitumor immune response. The network of blood vessels that arises in tumor is defective and func...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Objectives: Application of non-invasive imaging methods plays an important role in the assessment of cellular therapy effects in peripheral artery disease. The purpose of this work was to evaluate the kinetics of MRI-derived parameters characterizing ischaemic hindlimb muscle after administration of human mesenchymal stromal cells derived from adi...

Background: Adipose tissue-derived mesenchymal stromal cells (ASCs) have been shown to exhibit some promising properties of their use in regenerative medicine as advanced therapy medicinal products (ATMP). However, different sources of their origin, methods of isolation, and expansion procedures cause the laboratory and clinical results difficult...

Background Adipose-derived mesenchymal stromal cells (ADSCs) are multipotent stromal cells. The cells secrete a number of cytokines and growth factors and show immunoregulatory and proangiogenic properties. Their properties may be used to repair damaged tissues. The aim of our work is to explain the muscle damage repair mechanism with the utilizati...

Vascular disrupting agents as DMXAA inhibit tumor growth only for a short period of time followed by rapid tumor regrowth. Among others, hypoxia and presence of transcription factor HIF-1α are responsible for tumors regrowth. The aim of our study was to investigate the inhibition of murine melanoma growth by combining two agents: anti-vascular - DM...

Tumor-associated macrophages (TAMs) play a significant role in at least two key processes underlying neoplastic progression: angiogenesis and immune surveillance. TAMs phenotypic changes play important role in tumor vessel abnormalization/ normalization. M2-like TAMs stimulate immunosuppression and formation of defective tumor blood vessels leading...

Aims: The aim of the present study was to isolate mesenchymal stromal cells (MSC) with CD105+CD34- phenotype from human hearts, and to investigate their therapeutic potential in a mouse model of hindlimb ischemia and myocardial infarction (MI). The study aimed also to investigate the feasibility of xenogeneic MSCs implantation. Methods and result...

A detailed description of the methodology. (DOCX)

During neoplastic progression, cancer cells recruit inflammatory cells (monocytes, neutrophils, mast, and dendritic cells, etc.), which become "educated" under the influence of factors released by cancer cells (mainly cytokines). As a consequence, the former lose their ability to present antigens. Instead, they become cells involved in remodeling o...

Tumor progression depends on tumor milieu, which influences neovasculature formation and immunosuppression. Combining immunotherapy with antiangiogenic/antivascular therapy might be an effective therapeutic approach. The aim of our study was to elaborate an anticancer therapeutic strategy based on the induction of immune response which leads to pol...

According to literature data, self-renewing, multipotent, and clonogenic cardiac c-Kit(+) progenitor cells occur within human myocardium. The aim of this study was to isolate and characterize c-Kit(+) progenitor cells from explanted human hearts. Experimental material was obtained from 19 adult and 7 pediatric patients. Successful isolation and cul...

D-K6L9 peptide is bound by phosphatidylserine and induces necrosis in cancer cells. In our therapeutic experience, this peptide, when administered directly into B16-F10 murine melanoma tumors, inhibited their growth. Cessation of therapy results, however, in tumor relapse. We aimed at developing a combined therapy involving D-K6L9 and additional fa...

Myocardial infarction is underoxygenation-driven limited necrosis of heart tissues which results in elimination of ca. 0.5 to 1 billion spontaneously contracting cardiomyocytes (CM). Since the ability of human heart to regenerate is limited, efforts have been undertaken to increase the number of cardiomyocytes in post-infarction myocardium. Theoret...

Mesenchymal stromal cells (MSCs) have been among the most intensively studied cells in recent years. Lack of specific unique markers for these cells makes it difficult to distinguish MSCs from other types of cells, such as fibroblasts or pericytes. MSCs are a mixture of morphologically different cells with expression of various cellular markers, wi...

Development and neoplastic progression strongly rely on tumor microenvironment cells. Various kinds of cells that form such tumor milieu play substantial roles in angiogenesis and immunosuppression. Attempts to inhibit tumor vascularization alter tumor milieu and enhance immune response against the tumor. Anticancer therapeutic strategy bringing to...

A potential anti-melanoma prodrug containing a phenolic activator, a hydrazine linker, and a nitrogen mustard effector - (N-{4-[bis-(2-chloroethyl)amino]benzoyl}-N'-(4-hydroxybenzyl)hydrazine) has been synthesized in seven steps. Spectrophotometric measurements of its oxidation by tyrosinase showed a rapid increase of absorbance at 337 nm. HPLC ana...

Blood vascular supply significantly affects progression of tumor growth. Inhibition of endothelial cell proliferation by antiangiogenic drugs should lead to growth arrest of both primary tumors and metastases. During the course of lengthy therapy, endothelial cells may, however, become refractory to the action of antiangiogenic agents. Novel approa...

One of the preconditions of effective anticancer therapy is efficient transfer of the therapeutic agent (chemotherapeutic) to tumor cells. Fundamental barriers making drug delivery and action difficult include underoxygenation, elevated interstitial pressure, poor and abnormal tumor blood vascular network and acidic tumor milieu. In this study we a...

Certain anticancer drugs, such as the peptide CAMEL (aa sequence KWKLFKKIGAULKVL) induce necrotic type of cell death. During this process, a protein termed high mobility group box 1 (HMGB1) is released from cell nucleus into cytoplasm and then into extracellular milieu. Outside of cells, it becomes a proinflammatory cytokine. Its effects range from...

Abstract Cardiovascular research on myocardial physiology is often based on animal models of heart ischaemia. The model of left anterior descending (LAD) ligation in the mouse has been widely used to test various experimental hypotheses. However, there are significant discrepancies among studies not only in terms of technical aspects of the model,...

Specific cardiac stem/progenitor cells (CSCs/CPCs) are multipotent and clonogenic, giving rise to cardiomyocytes, smooth muscle cells and endothelial cells. These cells can be used in cell therapy for the treatment of diseased heart tissue, but there is a need for an effective targeting system that directs the cells to the infarcted area. The aim o...

History of cancer disease models clearly illustrates the evolving nature of these concepts. Since such models undergo continual revisions and additions as a result of underlying medical research, they also tend to reorganize knowledge and allow perceiving previously unseen relationships. Growth of medical thought has been influenced for many centur...

Glioblastoma multiforme is the most common and a particularly aggressive form of glial primary brain tumors. This malignancy accounts for ca. 70% of all diagnosed cases. Unfortunately, average survival of glioma patients does not exceed one year from diagnosis. Specific vascularization pattern (presence of numerous microvessels and glomerular vesse...

HMGB1 is an evolutionarily conserved protein with a wide spectrum of action. Its main receptors are RAGE and TLR found on the surface of immune system cells as well as endothelial cells. Although signaling pathways for both receptor groups are different, ultimately they both activate NFκB transcription factor which, in turn, activates genes encodin...

Growth of tumors usually depends on the development of the tumor’s own vasculature. Small avascular tumors (1–2 mm3) cannot continue growth provided an equilibrium between pro-angiogenic and anti-angiogenic factors is maintained within the tumor environment. Angiogenesis is not the only factor responsible for tumor blood vessels forming, as vasculo...

Cancer initiation and progression is strongly influenced by the tumor microenvironment consisting of various types of host cells (inflammatory cells, vascular cells and fibroblasts), extracellular matrix and non-matrix molecules. Host cells play a defining role in two major processes crucial for tumor growth: angiogenesis and escape from immune sur...

Vasculature is essential for the sustained growth of solid tumors and metastases. Tumor cells surviving vascular-disruptive therapeutic intervention (especially those present at the tumor rim) can contribute to tumor regrowth. The aim was to strengthen, by carrier-mediated delivery of a chemotherapeutic, the curative effects of a bifunctional anti-...

This study analyzed whether therapy with CAMEL, an antimicrobial peptide (KWKLFKKIGAVLKVL), possess anticancer benefits. Although the peptide was cytotoxic for all the cell lines tested, it did not cause hemolysis, which suggests that CAMEL does not damage cell membranes. After cellular internalization, CAMEL localized to mitochondria and lowered t...

Specialized variants of neoplastic cells that appear in tumors during cancer disease progression possess the ability to recruit certain kinds of hematopoietic and mesenchymal cells from the bone marrow or bloodstream. These tumor-recruited hematopoietic cells include monocytes, macrophages, granulocytes, mast and dendritic cells, as well as myelobl...

Murine melanoma B16F0 cells were transfected with SA:DPPC:DOPE (2:1:1 molar ratio) liposomes associated with a plasmid encoding murine IL-12. Stearylamine, a cationic lipid, showed a greater transfection efficiency compared to DOTAP-containing liposomes. The lipid:DNA ratio was 2:1 (w/w). Control groups were mock transfected or transfected with an...

Oxidation of the anti-Parkinsonian agent carbidopa by tyrosinase was investigated. The products of this reaction were identified as 3-(3,4-dihydroxyphenyl)-2-methylpropanoic acid and 6,7-dihydroxy-3-methylcinnoline. These results demonstrate that after oxidation of the catechol moiety to an o-quinone either a redox exchange with the hydrazine group...

It has been known that VEGF(121) isoform can serve as a carrier of therapeutic agents targeting tumor endothelial cells. We designed and constructed synthetic cDNA that encodes a chimeric protein comprising abrin-a (ABRaA) toxin A-chain and human VEGF(121). Expression of the ABRaA-VEGF(121) chimeric protein was carried out in E. coli strain BL21(DE...

The study aimed to check the effectiveness of anticancer therapy combining a vascular-disruptive drug (combretastatin phosphate, CA4P) and a liposomal formulation of a chemotherapeutic (doxorubicin). CA4P was synthesized in our laboratory according to a previously described procedure. The antivascular drug and long-circulating doxorubicin-loaded li...

Peptides are a novel class of anticancer agents embracing two distinct categories: natural antibacterial peptides, which are preferentially bound by cancer cells, and chemically synthesized peptides, which bind specifically to precise molecular targets located on the surface of tumor cells. Antibacterial peptides bind to both cell and mitochondrial...

Growth of tumors is strongly dependent upon supply of nutrients and oxygen by de novo formed blood vessels. Inhibiting angiogenesis suppresses growth of primary tumors as well and affects development of metastases. We demonstrate that recombinant MBP/vasostatin fusion protein inhibits proliferation of endothelial cells in vitro. The therapeutic use...

Hypoxia is an important feature of tumor microenvironment, exerting far-reaching effects on cells and contributing to cancer progression. Previous studies have established substantial differences in hypoxia response between various cell lines. Investigating this phenomenon in melanoma cells contributes to a better understanding of cell lineage-spec...

Vasculature targeting agents have been tested as cancer therapeutics for the past few years. Such therapy could be accomplished using, for example, bifunctional (two-domain) peptides. RGD-4C-GG-D(KLAKLAK)2, a peptide designed by Ellerby and coworkers (1999) (full sequence: ACDCRGDCFCGGKLAKLAKKLAKLAK), binds selectively to alphaVbeta3 integrin recep...

We investigated suppression of murine B16(F10) melanoma tumor growth following a therapy which involved concomitant administration of cyclophosphamide and plasmid DNA bearing interleukin-12 gene. Since both therapeutic factors display antiangiogenic capabilities, we assumed that their use in blocking the formation of new blood vessels would result...

Angiogenesis, i.e. formation of new blood vessels out of pre-existing capillaries, is essential to the development of tumour vasculature. The discovery of specific antiangiogenic inhibitors has important therapeutic implications for the development of novel cancer treatments. Vasostatin, the N-terminal domain of calreticulin, is a potent endogenous...

A 750 kDa polyethylenimine (PEI 750 kDa) combined with albumin has been found to mediate in vivo a highly efficient transfection of small amounts of plasmid DNA. Using this exceptional carrier system we evaluated the inflammatory responses triggered by CpG sequences found in plasmid DNA. Using as little as 1 mug DNA transferred in vivo caused an al...

Angioarrestin is a recently described anti-angiogenic protein whose expression is down-regulated in solid tumours of various origins. It has a sequence identical to angiopoietin related protein-1. In this study we investigated anti-tumour properties of angioarrestin in B16 (F10) melanoma tumour model. We constructed an expression vector encoding hu...

Unlabelled: This report describes gene transfer in vitro as well as in vivo using cetylated low-molecular mass (600 Da) polyethylenimine (28% of amine groups substituted with cetyl moieties), termed CT-PEI. This compound is hydrophobic and has to be incorporated into liposomes in order to be suitable for gene transfer studies. Serum-induced plasmi...

Recent studies have suggested that carcinoembryonic antigen (CEA)-promoter sequences are active only in CEA-positive cells, filing in the criteria for tumor specific targeting of suicide genes. However, the present study on gene therapy of colon cancer and cell-specificity of CEA promoter, provide evidence that CEA-positive and CEA-negative cells t...

A tumour therapy is proposed based on attenuated Salmonella typhimurium VNP20047 expressing the Escherichia coli cytosine deaminase gene. VNP20047 was administered intravenously to B16(F10) melanoma-bearing C57BL/6 mice. VNP20047 proliferated within tumours and livers regardless of the initial inoculum dose. After 10 days the number of bacteria inc...

Electroporation-mediated gene transfer relies upon direct delivery of plasmids into cells permeabilized by electric fields, a method more efficient than transfer using nonviral vectors, although neither approaches the transfer efficiency of viral vectors. Here we studied electrotransfer of a gene encoding an angiogenesis inhibitor (endostatin) into...

We compared the efficiency of in vitro DNA transfer into selected tumor and endothelial cell lines using complexes of plasmid DNA and cationic carriers: DDAB/DOPE, DC-Chol/DOPE, Arg-Chol/DOPE, Gly-Chol/DOPE, Arg-Gly-Chol/DOPE, BGTC/DOPE, and PEI. The best carriers for transfecting the majority of tested cells lines at optimized carrier-to-DNA weigh...