In vivo study of laser irradiation of fractionated drug administration based mechanism for effective photodynamic therapy in rat liver

Up-regulation of stress-activated proteins in cancer cells plays a protective role against photodynamic induced apoptosis. Post photodynamic therapy extracted normal rat liver tissue usually shows a fraction of surviving cells, the photodynamic resistant cells, residing in the necrotic region. To treat these photo-dynamic resistant cells a technique has been proposed based on fractionated drug administration of diluted photosensitizer, keeping the net concentration (5 mg/kg) constant, and subsequently varying drug light interval (DLI). Flourescence measurements were made for the presence of photosensitizer in a tissue. For qualitative analysis both histological and morphological studies were made. Although preliminary aim of this approach was not achieved but there were some interesting observation made i.e. for higher dilution of photosensitizer there was a sharp boundary between necrotic and normal portion of tissue. An increase in the absorption coefficient (alpha) from 2.7 -> 2.9 was observed as photosensitizer was diluted while the corresponding threshold dose (D (th)) persistently decreases from (0.10 -> 0.02) J/cm(2) when irradiated with a 635 nm laser fluence of 150 J/cm(2).

CD44/CD24 immunophenotypes on clinicopathologic features of salivary glands malignant neoplasms

Abstract Background Salivary Glands Malignant Neoplasms (SGMNs) account for 3-6% of head and neck cancers and 0.3% of all cancers. Tumor cells that express CD44 and CD24 exhibit a stem-cell-like behavior. CD44 is the binding site for hyaluronic acid, and CD24 is a receptor that interacts with P-selectin to induce metastasis and tumor progression. The present study aims to evaluate the expression of CD44 and CD24 on SGMNs and correlated these data with several clinicopathologic features. Methods Immunohistochemical stains for CD44 and CD24 were performed on tissue microarrays containing SGMN samples from 69 patients. The CD44, CD24 and CD44/CD24 expression phenotypes were correlated to patient clinicopathologic features and outcome. Results CD44 expression was associated with the primary site of neoplasm (p = 0.046). CD24 was associated with clinical stage III/IV (p = 0.008), T stage (p = 0,27) and lymph node (p = 0,001). The CD44/CD24 profiles were associated with the primary site of injury (p = 0.005), lymph node (p = 0.011) and T stage (p = 0.023). Univariate analysis showed a significant relationship between clinical staging and disease- free survival (p = 0.009), and the overall survival presents relation with male gender (p = 0.011) and metastasis (p = 0.027). Conclusion In summary, our investigation confirms that the clinical stage, in accordance with the literature, is the main prognostic factor for SGMN. Additionally, we have presented some evidence that the analysis of isolated CD44 and CD24 immunoexpression or the two combined markers could give prognostic information associated to clinicopathologic features in SGMN. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1284611098470676.

High aldehyde dehydrogenase activity identifies tumor-initiating and metastasis-initiating cells in human prostate cancer

Metastatic progression of advanced prostate cancer is a major clinical problem. Identifying the cell(s) of origin in prostate cancer and its distant metastases may permit the development of more effective treatment and preventive therapies. In this study, aldehyde dehydrogenase (ALDH) activity was used as a basis to isolate and compare subpopulations of primary human prostate cancer cells and cell lines. ALDH-high prostate cancer cells displayed strongly elevated clonogenicity and migratory behavior in vitro. More strikingly, ALDH-high cells readily formed distant metastases with strongly enhanced tumor progression at both orthotopic and metastatic sites in preclinical models. Several ALDH isoforms were expressed in human prostate cancer cells and clinical specimens of primary prostate tumors with matched bone metastases. Our findings suggest that ALDH-based viable cell sorting can be used to identify and characterize tumor-initiating and, more importantly perhaps, metastasis-initiating cells in human prostate cancer.

Multi-Scale Modeling for Image Analysis of Brain Tumor Studies

Image-based modeling of tumor growth combines methods from cancer simulation and medical imaging. In this context, we present a novel approach to adapt a healthy brain atlas to MR images of tumor patients. In order to establish correspondence between a healthy atlas and a pathologic patient image, tumor growth modeling in combination with registration algorithms is employed. In a first step, the tumor is grown in the atlas based on a new multi-scale, multi-physics model including growth simulation from the cellular level up to the biomechanical level, accounting for cell proliferation and tissue deformations. Large-scale deformations are handled with an Eulerian approach for finite element computations, which can operate directly on the image voxel mesh. Subsequently, dense correspondence between the modified atlas and patient image is established using nonrigid registration. The method offers opportunities in atlasbased segmentation of tumor-bearing brain images as well as for improved patient-specific simulation and prognosis of tumor progression.

Impact of CD39 and purinergic signalling on the growth and metastasis of colorectal cancer

Despite improvements in prevention and management of colorectal cancer (CRC), uncontrolled tumor growth with metastatic spread to distant organs remains an important clinical concern. Genetic deletion of CD39, the dominant vascular and immune cell ectonucleotidase, has been shown to delay tumor growth and blunt angiogenesis in mouse models of melanoma, lung and colonic malignancy. Here, we tested the influence of CD39 on CRC tumor progression and metastasis by investigating orthotopic transplanted and metastatic cancer models in wild-type BALB/c, human CD39 transgenic and CD39 deficient mice. We also investigated CD39 and P2 receptor expression patterns in human CRC biopsies. Murine CD39 was expressed by endothelium, stromal and mononuclear cells infiltrating the experimental MC-26 tumors. In the primary CRC model, volumes of tumors in the subserosa of the colon and/or rectum did not differ amongst the treatment groups at day 10, albeit these tumors rarely metastasized to the liver. In the dissemination model, MC-26 cell line-derived hepatic metastases grew significantly faster in CD39 over-expressing transgenics, when compared to CD39 deficient mice. Murine P2Y2 was significantly elevated at both mRNA and protein levels, within the larger liver metastases obtained from CD39 transgenic mice where changes in P2X7 levels were also noted. In clinical samples, lower levels of CD39 mRNA in malignant CRC tissues appeared associated with longer duration of survival and could be linked to less invasive tumors. The modulatory effects of CD39 on tumor dissemination and differential levels of CD39, P2Y2 and P2X7 expression in tumors suggest involvement of purinergic signalling in these processes. Our studies also suggest potential roles for purinergic-based therapies in clinical CRC.

Negative regulation of NF-κB by the ING4 tumor suppressor in breast cancer

Nuclear Factor kappa B (NF-κB) is a key mediator of normal immune response but contributes to aggressive cancer cell phenotypes when aberrantly activated. Here we present evidence that the Inhibitor of Growth 4 (ING4) tumor suppressor negatively regulates NF-κB in breast cancer. We surveyed primary breast tumor samples for ING4 protein expression using tissue microarrays and a newly generated antibody. We found that 34% of tumors expressed undetectable to low levels of the ING4 protein (n = 227). Tumors with low ING4 expression were frequently large in size, high grade, and lymph node positive, suggesting that down-regulation of ING4 may contribute to breast cancer progression. In the same tumor set, we found that low ING4 expression correlated with high levels of nuclear phosphorylated p65/RelA (p-p65), an activated form of NF-κB (p = 0.018). Fifty seven percent of ING4-low/p-p65-high tumors were lymph node-positive, indicating a high metastatic tendency of these tumors. Conversely, ectopic expression of ING4 inhibited p65/RelA phosphorylation in T47D and MCF7 breast cancer cells. In addition, ING4 suppressed PMA-induced cell invasion and NF-κB-target gene expression in T47D cells, indicating that ING4 inhibited NF-κB activity in breast cancer cells. Supportive of the ING4 function in the regulation of NF-κB-target gene expression, we found that ING4 expression levels inversely correlated with the expression of NF-κB-target genes in primary breast tumors by analyzing public gene expression datasets. Moreover, low ING4 expression or high expression of the gene signature composed of a subset of ING4-repressed NF-κB-target genes was associated with reduced disease-free survival in breast cancer patients. Taken together, we conclude that ING4 negatively regulates NF-κB in breast cancer. Consequently, down-regulation of ING4 leads to activation of NF-κB, contributing to tumor progression and reduced disease-free patient survival in breast cancer.

Secretin receptors in the human liver: expression in biliary tract and cholangiocarcinoma, but not in hepatocytes or hepatocellular carcinoma

BACKGROUND/AIMS: Gut hormone receptors are over-expressed in human cancer and allow receptor-targeted tumor imaging and therapy. A novel promising receptor for these purposes is the secretin receptor. The secretin receptor expression was investigated in the human liver because the liver is a physiological secretin target and because novel diagnostic and treatment modalities are needed for liver cancer. METHODS: Nineteen normal livers, 10 cirrhotic livers, 35 cholangiocarcinomas, and 45 hepatocellular carcinomas were investigated for secretin receptor expression by in vitro receptor autoradiography using (125)I-[Tyr(10)] rat secretin and, in selected cases, for secretin receptor mRNA by RT-PCR. RESULTS: Secretin receptors were present in normal bile ducts and ductules, but not in hepatocytes. A significant receptor up-regulation was observed in ductular reaction in liver cirrhosis. Twenty-two (63%) cholangiocarcinomas were positive for secretin receptors, while hepatocellular carcinomas were negative. RT-PCR revealed wild-type receptor mRNA in the non-neoplastic liver, wild-type and spliced variant receptor mRNAs in cholangiocarcinomas found receptor positive in autoradiography experiments, and no receptor transcripts in autoradiographically negative cholangiocarcinomas. CONCLUSIONS: The expression of secretin receptors in the biliary tract is the molecular basis of the secretin-induced bicarbonate-rich choleresis in man. The high receptor expression in cholangiocarcinomas may be used for in vivo secretin receptor-targeting of these tumors and for the differential diagnosis with hepatocellular carcinoma.

Treatment with (90)Y- and (177)Lu-DOTATOC in patients with metastatic neuroendocrine tumors

BACKGROUND: Treatment with (90)Y- or (177)Lu-DOTATOC has recently been introduced in the palliative treatment of somatostatin receptor-expressing neuroendocrine tumors (NETs). The aim of the study was to present clinical experience with (90)Y- and (177)Lu-DOTATOC therapy in the management of NET. METHODS: To prove suitability for treatment each patient underwent scanning with (111)In-DTPAOC or (68)Ga-DOTATOC positron emission tomography/computed tomography. All patients received [(90)Y-DOTATOC] as initial treatment. In case of disease relapse the treatment was repeated. To avoid side effects of repeated [(90)Y] applications, a switch to [(177)Lu-DOTATOC] was carried out. Clinical, biochemical, and radioimaging responses were documented. RESULTS: Twenty patients with metastatic nonresectable NETs (15 pancreas NETs, 2 midgut NETs, 1 gastrinoma, 1 paraganglioma, 1 NET of unknown primary origin) were included. In 8 patients the treatment was repeated more than once (mean, 3 times; range, 2-5 times). After [(90)Y] treatment moderate toxicity was observed in 8 patients. No serious adverse events were documentable. After restaging, a partial remission was found in 5 patients, stable disease in 11 patients, and tumor progression in 4 patients. CONCLUSIONS: Peptide receptor-targeted radionuclide therapy is a promising, safe, and feasible approach in the palliative therapy of patients with NET.

Targeting CCK receptors in human cancers

Gut hormone receptors can be over-expressed in several human cancers and represent the basis for receptor-targeted tumor imaging and therapy. A promising receptor for such clinical applications is the cholecystokinin receptor. Cholecystokinin receptors are expressed in numerous neuroendocrine tumors, in particular medullary thyroid carcinomas and neuroendocrine gut tumors, as well as in stromal tumors. Moreover, several radiolabeled CCK or gastrin analogs have been developed allowing to detect these tumors and their metastases in patients using in vivo cholecystokinin receptor scintigraphy, proving the feasibility of targeting CCK receptors in human tumors in vivo.

Wild-type and splice-variant secretin receptors in lung cancer: overexpression in carcinoid tumors and peritumoral lung tissue

Gastrointestinal peptide hormone receptors, like somatostatin receptors, are often overexpressed in human cancer, allowing receptor-targeted tumor imaging and therapy. A novel candidate for these applications is the secretin receptor recently identified in pancreatic and cholangiocellular carcinomas. In the present study, secretin receptors were assessed in a non-gastrointestinal tissue, the human lung. Non-small-cell lung cancers (n=26), small-cell lung cancers (n=10), bronchopulmonary carcinoid tumors (n=29), and non-neoplastic lung (n=46) were investigated for secretin receptor protein expression with in vitro receptor autoradiography, using (125)I-[Tyr(10)] rat secretin and for secretin receptor transcripts with RT-PCR. Secretin receptor protein expression was found in 62% of bronchopulmonary carcinoids in moderate to high density, in 12% of non-small cell lung cancers in low density, but not in small cell lung cancers. In tumors found to be secretin receptor positive by autoradiography, RT-PCR revealed transcripts for the wild-type secretin receptor and for novel secretin receptor splice variants. In the non-neoplastic lung, secretin receptor protein expression was observed in low density along the alveolar septa in direct tumor vicinity in cases of acute inflammation, but not in histologically normal lung. In the autoradiographically positive peritumoral lung, RT-PCR showed transcripts for the wild-type secretin receptor and for a secretin receptor spliceoform different from those occurring in lung and gut tumors. In conclusion, secretin receptors are new markers for bronchopulmonary carcinoid tumors, and represent the molecular basis for an in vivo targeting of carcinoid tumors for diagnosis and therapy. Furthermore, secretin receptors may play a role in peritumoral lung pathophysiology. Secretin receptor mis-splicing specifically occurs in tumor and non-tumor lung pathology.

Alternative splicing of pre-mRNA in cancer: focus on G protein-coupled peptide hormone receptors

Through alternative splicing, multiple different transcripts can be generated from a single gene. Alternative splicing represents an important molecular mechanism of gene regulation in physiological processes such as developmental programming as well as in disease. In cancer, splicing is significantly altered. Tumors express a different collection of alternative spliceoforms than normal tissues. Many tumor-associated splice variants arise from genes with an established role in carcinogenesis or tumor progression, and their functions can be oncogenic. This raises the possibility that products of alternative splicing play a pathogenic role in cancer. Moreover, cancer-associated spliceoforms represent potential diagnostic biomarkers and therapeutic targets. G protein-coupled peptide hormone receptors provide a good illustration of alternative splicing in cancer. The wild-type forms of these receptors have long been known to be expressed in cancer and to modulate tumor cell functions. They are also recognized as attractive clinical targets. Recently, splice variants of these receptors have been increasingly identified in various types of cancer. In particular, alternative cholecystokinin type 2, secretin, and growth hormone-releasing hormone receptor spliceoforms are expressed in tumors. Peptide hormone receptor splice variants can fundamentally differ from their wild-type receptor counterparts in pharmacological and functional characteristics, in their distribution in normal and malignant tissues, and in their potential use for clinical applications.

Tenascin-C downregulates wnt inhibitor dickkopf-1, promoting tumorigenesis in a neuroendocrine tumor model

The extracellular matrix molecule tenascin-C (TNC) is a major component of the cancer-specific matrix, and high TNC expression is linked to poor prognosis in several cancers. To provide a comprehensive understanding of TNC's functions in cancer, we established an immune-competent transgenic mouse model of pancreatic β-cell carcinogenesis with varying levels of TNC expression and compared stochastic neuroendocrine tumor formation in abundance or absence of TNC. We show that TNC promotes tumor cell survival, the angiogenic switch, more and leaky vessels, carcinoma progression, and lung micrometastasis. TNC downregulates Dickkopf-1 (DKK1) promoter activity through the blocking of actin stress fiber formation, activates Wnt signaling, and induces Wnt target genes in tumor and endothelial cells. Our results implicate DKK1 downregulation as an important mechanism underlying TNC-enhanced tumor progression through the provision of a proangiogenic tumor microenvironment.

Integrated Segmentation of Brain Tumor Images for Radiotherapy and Neurosurgery

Image-based modeling of tumor growth combines methods from cancer simulation and medical imaging. In this context, we present a novel approach to adapt a healthy brain atlas to MR images of tumor patients. In order to establish correspondence between a healthy atlas and a pathologic patient image, tumor growth modeling in combination with registration algorithms is employed. In a first step, the tumor is grown in the atlas based on a new multi-scale, multi-physics model including growth simulation from the cellular level up to the biomechanical level, accounting for cell proliferation and tissue deformations. Large-scale deformations are handled with an Eulerian approach for finite element computations, which can operate directly on the image voxel mesh. Subsequently, dense correspondence between the modified atlas and patient image is established using nonrigid registration. The method offers opportunities in atlasbased segmentation of tumor-bearing brain images as well as for improved patient-specific simulation and prognosis of tumor progression.

Repression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) but not its receptors during oral cancer progression.

BACKGROUND: TRAIL plays an important role in host immunosurveillance against tumor progression, as it induces apoptosis of tumor cells but not normal cells, and thus has great therapeutic potential for cancer treatment. TRAIL binds to two cell-death-inducing (DR4 and DR5) and two decoy (DcR1, and DcR2) receptors. Here, we compare the expression levels of TRAIL and its receptors in normal oral mucosa (NOM), oral premalignancies (OPM), and primary and metastatic oral squamous cell carcinomas (OSCC) in order to characterize the changes in their expression patterns during OSCC initiation and progression. METHODS: DNA microarray, immunoblotting and immunohistochemical analyses were used to examine the expression levels of TRAIL and its receptors in oral epithelial cell lines and in archival tissues of NOM, OPM, primary and metastatic OSCC. Apoptotic rates of tumor cells and tumor-infiltrating lymphocytes (TIL) in OSCC specimens were determined by cleaved caspase 3 immunohistochemistry. RESULTS: Normal oral epithelia constitutively expressed TRAIL, but expression was progressively lost in OPM and OSCC. Reduction in DcR2 expression levels was noted frequently in OPM and OSCC compared to respective patient-matched uninvolved oral mucosa. OSCC frequently expressed DR4, DR5 and DcR1 but less frequently DcR2. Expression levels of DR4, DR5 and DcR1 receptors were not significantly altered in OPM, primary OSCC and metastatic OSCC compared to patient-matched normal oral mucosa. Expression of proapoptotic TRAIL-receptors DR4 and DR5 in OSCC seemed to depend, at least in part, on whether or not these receptors were expressed in their parental oral epithelia. High DR5 expression in primary OSCC correlated significantly with larger tumor size. There was no significant association between TRAIL-R expression and OSSC histology grade, nodal status or apoptosis rates of tumor cells and TIL. CONCLUSION: Loss of TRAIL expression is an early event during oral carcinogenesis and may be involved in dysregulation of apoptosis and contribute to the molecular carcinogenesis of OSCC. Differential expressions of TRAIL receptors in OSCC do not appear to play a crucial role in their apoptotic rate or metastatic progression.

Gene Therapy for Pediatric Cancer: State of the Art and Future Perspectives.

While modern treatments have led to a dramatic improvement in survival for pediatric malignancy, toxicities are high and a significant proportion of patients remain resistant. Gene transfer offers the prospect of highly specific therapies for childhood cancer. "Corrective" genes may be transferred to overcome the genetic abnormalities present in the precancerous cell. Alternatively, genes can be introduced to render the malignant cell sensitive to therapeutic drugs. The tumor can also be attacked by decreasing its blood supply with genes that inhibit vascular growth. Another possible approach is to modify normal tissues with genes that make them more resistant to conventional drugs and/or radiation, thereby increasing the therapeutic index. Finally, it may be possible to attack the tumor indirectly by using genes that modify the behavior of the immune system, either by making the tumor more immunogenic, or by rendering host effector cells more efficient. Several gene therapy applications have already been reported for pediatric cancer patients in preliminary Phase 1 studies. Although no major clinical success has yet been achieved, improvements in gene delivery technologies and a better understanding of mechanisms of tumor progression and immune escape have opened new perspectives for the cure of pediatric cancer by combining gene therapy with standard therapeutic available treatments.