Enhancement of artificial lung metastases in mice caused by cyclophosphamide

Summary The capacity of IV injected fibrosarcoma cells to form metastatic nodules in the lungs of corresponding syngeneic CBA mice was enhanced by pretreatment of tumor cell recipients with cyclophosphamide. The effet depended upon the dose but not upon the injection route of cyclophosphamide. The enhancement of lung-colony formation lasted for about 10 days after injection of the drug, with its maximum at day 1. Cyclophosphamide was also effective in whole body-irradiated and TIR mice. Its effect, however, was abolished to a great extent by reconstituting mice with nonseparated or nonadherent spleen and bone marrow cells from either normal or TIR mice. Lymphoid cells from CY-treated mice, however, had no such reconstitutive capacity. These observations imply that the cyclophosphamide-induced enhancement of tumor metastasis formation was partly due to nonimmunologic factors and partly due to suppression of non-T lymphocytes.     

Fine needle aspiration cytology of mesenchymal hamartoma of the liver. A case report

BACKGROUND: Mesenchymal hamartoma (MH) of the liver constitutes the third or fourth most common tumor of the liver in childhood and occurs most commonly in the first two years of life. MHs of the liver are seldom aspirated, and reports on the role of fine needle aspiration (FNA) in the diagnosis of MH are scarce. Clinically, cytologically and even histologically, MH can be mistaken for a number of reactive and neoplastic hepatic lesions that may occur in children under 2 years of age. CASE: A 10-month-old Pakistani female presented with a history of a right-sided, nonpainful abdominal swelling. Abdominal computed tomography showed a large, partly solid and partly cystic, heterogeneous hepatic mass. FNA cytology showed clusters of both epithelial and mesenchymal/spindle-shaped cells with pieces of loose connective tissue. A cytologic differential diagnosis of mesenchymal hepatic hamartoma and hepatoblastoma of the possible mixed mesenchymal/epithelial subtype was rendered. The histopathologic diagnosis of the resected tumor mass was benign mesenchymal hamartoma of the liver. CONCLUSION: In children under 2 years of age who present with partly solid and partly cystic hepatic masses, the possibility of MH of the liver should be considered. FNA has a role in the diagnosis of MH. The cytopathologist should be aware of the patient's age, radiologic features and cytologic appearances of this rare, benign neoplasm. Histologic examination of tru-cut biopsies and immunohistochemical stains can help to exclude other pediatric neoplasms that may show cytologic features similar to or mimicking those of MH.     

On the mechanism of glycolysis stimulation by neutral detergents in 3T3 and Ehrlich ascites tumor cells

Glycolysis of 3T3 and Ehrlich ascites tumor cells was greatly enhanced by Nonidet P-40 or Triton X-100 at about 100 micrograms/mg cell protein. This enhanced glycolysis was partly sensitive to rutamycin and partly sensitive to ouabain, suggesting that the detergent released the control of the ATPase of the mitochondria and of the plasma membrane Na+K+-ATPase. Nonidet P-40 had no effect on glycolysis in cell-free extracts from Ehrlich ascites tumor cells to which soluble mitochondrial ATPase was added. Measuring ouabain-sensitive 22Na efflux and using ouabain-sensitive lactate production as a measure of ATP hydrolysis by the Na+K+ pump, it was shown that Nonidet P-40 greatly decreased the efficiency of the Na+K+ pump. Quercetin increased the efficiency of pumping in EAT cells both in the absence and presence of the detergent.     

Does the tumor microenvironment influence radiation-induced apoptosis?

Cytotoxic anti-cancer agents induce apoptosis in tumor and normal tissues. Therefore, it is important to investigate which factors determine these apoptotic processes and hence their likely impact on therapeutic gain. Radiation-induced apoptosis in tumors may be inhibited due to mutations of apoptotic elements or to tumor microenvironmental conditions arising from vascular insufficiency. Tumors typically contain regions of hypoxia, low glucose and acidosis. Hypoxic cells compromise treatment partly because of reduced fixation of damage during radiotherapy and partly because they promote a more malignant phenotype. There is also evidence that hypoxia may inhibit apoptosis. For some cell types, concurrent hypoxia may modulate radiation-induced apoptosis while, for others, post-irradiation hypoxia may be required. This may reflect the activity of different apoptotic pathways. Pathways involving mitochondrial components as well as regulation of SAPK and Fas have been implicated. In addition, several key stages in apoptosis are sensitive to depletion of cellular energy reserves, which results from hypoxia and low glucose conditions. There is also evidence that low pH in tumors can interfere with radiation-induced apoptosis, partly through cell cycle arrest and other undefined mechanisms. Conclusions: Hypoxia, low glucose and acidosis influence radiation-induced apoptosis and thus may be detrimental to radiotherapy.     

Epigenetic quantification of tumor-infiltrating T-lymphocytes

The immune system plays a pivotal role in tumor establishment. However, the role of T-lymphocytes within the tumor microenvironment as major cellular component of the adaptive effector immune response and their counterpart, regulatory T cells (Treg), responsible for suppressive immune modulation, is not completely understood. This is partly due to the lack of reliable technical solutions for specific cell quantification in solid tissues. Previous reports indicated that epigenetic marks of immune cells, such as the Treg specifically demethylated region (TSDR) within the FOXP3 gene, may be exploited as robust analytical tool for Treg-quantification. Here, we expand the concept of epigenetic immunophenotyping to overall T-lymphocytes (oTL). This tool allows cell quantification with at least equivalent precision to FACS and is adoptable for analysis of blood and solid tissues. Based on this method, we analyze the frequency of Treg, oTL and their ratio in independent cohorts of healthy and tumorous ovarian, colorectal and bronchial tissues with 616 partly donor-matched samples. We find a shift of the median ratio of Treg-to-oTL from 3–8% in healthy tissue to 18–25% in all tumor entities. Epigenetically determined oTL frequencies correlate with the outcome of colorectal and ovarian cancers. Together, our data show that the composition of immune cells in tumor microenvironments can be quantitatively assessed by epigenetic measurements. This composition is disturbed in solid tumors, indicating a fundamental mechanism of tumor immune evasion. Epigenetic quantification of T-lymphocytes serves as independent clinical parameter for outcome prognosis.Key words: tumor immunology, regulatory T cells, T-lymphocytes, epigenetic immunophenotyping, DNA methylation     

IL-27 Enhances the Expression of TRAIL and TLR3 in Human Melanomas and Inhibits Their Tumor Growth in Cooperation with a TLR3 Agonist Poly(I:C) Partly in a TRAIL-Dependent Manner

Interleukin (IL)-27 is a member of the IL-6/IL-12 cytokine family and possesses potent antitumor activity, which is mediated by multiple mechanisms. Toll-like receptor (TLR)3 is the critical sensor of the innate immune system that serves to identify viral double-stranded RNA. TLR3 is frequently expressed by various types of malignant cells, and recent studies reported that a synthetic TLR3 agonist, polyinosinic-polycytidylic acid [poly(I:C)], induces antitumor effects on malignant cells. In the present study, we have explored the effect of IL-27 on human melanomas and uncovered a previously unknown mechanism. We found that IL-27 inhibits in vitro tumor growth of human melanomas and greatly enhances the expression of TNF-related apoptosis inducing ligand (TRAIL) in a dose-dependent manner. Neutralizing antibody against TRAIL partly but significantly blocked the IL-27–mediated inhibition of tumor growth. In addition, IL-27 and poly(I:C) cooperatively augmented TRAIL expression and inhibited tumor growth. The cooperative effect could be ascribed to the augmented expression of TLR3, but not retinoic acid-inducible gene-I or anti-melanoma differentiation-associated gene 5, by IL-27. The inhibition of tumor growth by the combination was also significantly abrogated by anti-TRAIL neutralizing antibody. Moreover, IL-27 and poly(I:C) cooperatively suppressed in vivo tumor growth of human melanoma in immunodeficient mice. Taken together, these results suggest that IL-27 enhances the expression of TRAIL and TLR3 in human melanomas and inhibits their tumor growth in cooperation with poly(I:C), partly in a TRAIL-dependent manner. Thus, IL-27 and the combination of IL-27 and poly(I:C) may be attractive candidates for cancer immunotherapy.     

Lung cancer xenografting alters microRNA profile but not immunophenotype

Lung tumor xenografts grown in immunocompromised mice provide a renewable source of tumor tissue for research and a means to study individualized response to chemotherapy. Critical to this utility is verification that the xenograft cells retain core phenotypic characteristics of the original tumor. We compared eight non-small cell lung carcinomas with their corresponding xenografts grown in mice with severe combined immunodeficiency by way of histology, immunohistochemistry, and microRNA expression profiling. Six of the eight xenografts closely resembled their original tumor by light microscopy. The xenografts also largely retained key immunophenotypic features. With expression profiling of human microRNAs, however, xenografts clustered separately from the original tumors. While this may be partly due to contamination by non-neoplastic human and mouse stroma, the results suggest that miRNA expression may be altered in xenografts and that this possibility should be further evaluated.     

Vessel abnormalization: another hallmark of cancer? Molecular mechanisms and therapeutic implications

As a result of excessive production of angiogenic molecules, tumor vessels become abnormal in structure and function. By impairing oxygen delivery, abnormal vessels fuel a vicious cycle of non-productive angiogenesis, which creates a hostile microenvironment from where tumor cells escape through leaky vessels and which renders tumors less responsive to chemoradiation. While anti-angiogenic strategies focused on inhibiting new vessel growth and destroying pre-existing vessels, clinical studies showed modest anti-tumor effects. For many solid tumors, anti-VEGF treatment offers greater clinical benefit when combined with chemotherapy. This is partly due to a normalization of the tumor vasculature, which improves cytotoxic drug delivery and efficacy and offers unprecedented opportunities for anti-cancer treatment. Here, we overview key novel molecular players that induce vessel normalization.     

Scratch cytologic findings on surgically resected solitary fibrous tumors of the pleura

OBJECTIVE: To ascertain the cytologic characteristics of solitary fibrous tumors of the pleura (SFTPs) on smear preparations. STUDY DESIGN: Fine needle aspiration cytology (FNAC) was initially attempted preoperatively in five cases, but the specimens were inappropriate for interpretation because only a few tumor cells were obtained. Therefore, scratch smears made at the time of operation were used. Papanicolaou and immunocytochemical staining was performed in all 10 cases, 2 of which were malignant. RESULTS: As expected, cellular tumors yielded more cells. The cytologic appearance was variable, showing spindle/bipolar, dendritic/stellate and intermediate cells. Atypical cells reminiscent of sarcoma were also present in cellular, benign tumors. Highly atypical epithelioid cells were obtained in two malignant cases. Immunocytochemically, the tumor cells were positive for CD34 and vimentin and negative for cytokeratin, regardless of histologic differences and cell shape. CONCLUSION: It seems difficult to diagnose SFTPs with certainty by FNAC, partly because the cell morphology of SFTPs resembles a wide variety of heterogeneous groups of spindle cell tumors and partly because only a few tumor cells were available in the FNAC specimens in the present study. However, a cytologic diagnosis of SFTP is possible if cytologic preparations yield CD34-positive cells with spindle/bipolar or dendritic/stellate morphology.     

Compact oleic acid in HAMLET

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex between alpha-lactalbumin and oleic acid that induces apoptosis in tumor cells, but not in healthy cells. Heteronuclear nuclear magnetic resonance (NMR) spectroscopy was used to determine the structure of 13C-oleic acid in HAMLET, and to study the 15N-labeled protein. Nuclear Overhauser enhancement spectroscopy shows that the two ends of the fatty acid are in close proximity and close to the double bond, indicating that the oleic acid is bound to HAMLET in a compact conformation. The data further show that HAMLET is a partly unfolded/molten globule-like complex under physiological conditions.     

Astrocytes Directly Influence Tumor Cell Invasion and Metastasis In Vivo

Brain metastasis is a defining component of tumor pathophysiology, and the underlying mechanisms responsible for this phenomenon are not well understood. Current dogma is that tumor cells stimulate and activate astrocytes, and this mutual relationship is critical for tumor cell sustenance in the brain. Here, we provide evidence that primary rat neonatal and adult astrocytes secrete factors that proactively induced human lung and breast tumor cell invasion and metastasis capabilities. Among which, tumor invasion factors namely matrix metalloprotease-2 (MMP-2) and MMP-9 were partly responsible for the astrocyte media-induced tumor cell invasion. Inhibiting MMPs reduced the ability of tumor cell to migrate and invade in vitro. Further, injection of astrocyte media-conditioned breast cancer cells in mice showed increased invasive activity to the brain and other distant sites. More importantly, blocking the preconditioned tumor cells with broad spectrum MMP inhibitor decreased the invasion and metastasis of the tumor cells, in particular to the brain in vivo. Collectively, our data implicate astrocyte-derived MMP-2 and MMP-9 as critical players that facilitate tumor cell migration and invasion leading to brain metastasis.     

Inferring tree models for oncogenesis from comparative genome hybridization data.

Comparative genome hybridization (CGH) is a laboratory method to measure gains and losses of chromosomal regions in tumor cells. It is believed that DNA gains and losses in tumor cells do not occur entirely at random, but partly through some flow of causality. Models that relate tumor progression to the occurrence of DNA gains and losses could be very useful in hunting cancer genes and in cancer diagnosis. We lay some mathematical foundations for inferring a model of tumor progression from a CGH data set. We consider a class of tree models that are more general than a path model that has been developed for colorectal cancer. We derive a tree model inference algorithm based on the idea of a maximum-weight branching in a graph, and we show that under plausible assumptions our algorithm infers the correct tree. We have implemented our methods in software, and we illustrate with a CGH data set for renal cancer.     

关于细胞毒因子抗肿瘤活性的研究

用抗肿瘤免疫RNA诱生家兔,用体外细胞毒实验证明.i—RNA致敏血清对人和鼠的肿瘤细胞株有不同程度的杀伤作用,从血清中的细胞毒活性粗提液经局部和静脉注入实体瘤鼠体内,见肿瘤组织有出血、坏死、细胞核溶解,消失等现象。     

Colorectal carcinoma. DNA ploidy pattern and prognosis with reference to tumor DNA heterogeneity.

Nuclear DNA content was measured in 72 colorectal carcinomas using single-cell microspectrophotometry on Feulgen-stained smears. Four samples were analyzed from each tumor. Patients were followed for 41-65 months (average, 53). DNA heterogeneity (both aneuploid and nonaneuploid patterns) was present in 44% of the cases. Sixty-eight percent of the tumors showed an aneuploid DNA pattern in at least one of the samples. Patients with nonaneuploid tumors tended to have a survival advantage over patients with homogeneously aneuploid tumors and demonstrated a significantly longer disease-free survival. The DNA ploidy pattern is of potential value in conjunction with histopathologic prognostic parameters in colorectal carcinoma. Since colorectal tumors exhibit pronounced DNA heterogeneity, multiple samples are required from each tumor to permit a proper evaluation of its DNA pattern. The DNA heterogeneity may represent tumor progression and can partly explain the conflicting results reported concerning DNA pattern and prognosis in colorectal carcinoma.     

Exploration of tumor penetrating peptide iRGD as a potential strategy to enhance tumor penetration of cancer nanotherapeutics

Cancer therapy continues to be a huge challenge as most chemotherapeutic agents exert serious adverse effects on healthy organs. Chemotherapeutic agents lack selective targeting and even the existing target specific therapies are failing due to poor distribution into the tumor microenvironment. Nanotechnology offers multiple advantages to address the limitations encountered by conventional therapy. However, the delivery of nanotherapeutics to tumor tissue has not improved over the years partly due to the poor and inadequate distribution of nanotherapeutics into deeper tumor regions resulting in resistance and relapse. To curb the penetration concerns, iRGD was explored and found to be highly effective in improving the delivery of cancer nanomedicine. The preclinical observations are highly encouraging; however, the clinical translation is at a nascent stage. Based on this, we have made an elaborative effort to give a detailed account of various promising applications of iRGD to increase anticancer and tumor imaging potential. Importantly, we have comprehensively discussed the shortcomings and uncertainties associated with the clinical translation of iRGD-based therapeutic approaches and future directions.     

Small molecules inhibit ex vivo tumor growth in bone

Bone is a common site of metastasis for breast, prostate, lung, kidney and other cancers. Bone metastases are incurable, and substantially reduce patient quality of life. To date, there exists no small-molecule therapeutic agent that can reduce tumor burden in bone. This is partly attributed to the lack of suitable in vitro assays that are good models of tumor growth in bone. Here, we take advantage of a novel ex vivo model of bone colonization to report a series of pyrrolopyrazolone small molecules that inhibit cancer cell invasion and ex vivo tumor growth in bone at single-digit micromolar concentration. We find that the compounds modulated the expression levels of genes associated with bone-forming osteoblasts, bone-destroying osteoclasts, cancer cell viability and metastasis. Our compounds provide chemical tools to uncover novel targets and pathways associated with bone metastasis, as well as for the development of compounds to prevent and reverse bone tumor growth in vivo.     

CD44S-hyaluronan interactions protect cells resulting from EMT against anoikis

The detachment of normal epithelial cells from matrix triggers an apoptotic response known as anoikis, during homeostatic turnover. Metastatic tumor cells evade anoikis, by mechanisms that are only partly characterized. In particular, the epithelial–mesenchymal transition (EMT) in a subset of invasive tumor cells confers anoikis-resistance. In some cases, EMT up-regulates the cancer stem cell marker CD44S and the enzyme hyaluronic acid synthase-2 (HAS2). CD44S is the major receptor for hyaluronan in the extracellular matrix. Herein, we demonstrate that CD44S, unlike the CD44E isoform expressed in normal epithelial cells, contributes to the protection against anoikis. This protection requires the interaction of CD44S with hyaluronan (HA). CD44S–HA interaction is proposed to play an important role in tumor metastasis through enhanced cell survival under detached conditions.     

Three-dimensional microfluidic tumor–macrophage system for breast cancer cell invasion

The recrudescence of breast cancer can partly be attributed to poor understanding of the early steps and the mechanisms involved in breast cancer metastasis, especially how tumor inflammatory cells including tumor-associated macrophages (TAM) affect invasion process. However, invasion-related biological studies in traditional in vitro assays or in vivo models are challenging due to the arduousness in establishing models that precisely reproduce the tumor invasion environment. To this end, we proposed a juxtaposed dual-layer cell-loaded hydrogels biomimetic microfluidic system and formed monolayer size-selective permeable vascular endothelial barriers besides the dual layer to mimic mammalian blood vessels. We clarified that in this system, TAM promoted the invasion of breast cancer cells, whereas breast cancer cells maintained the phenotype of TAM cells and promoted the differentiation of U937 cells into TAM. It formed a tumor–macrophage bidirectional crosstalk system. This system could be used for drug screening. So finally, through the calculation of the survival rate of breast cancer cells when cocultured with different macrophages under paclitaxel treatment, we analyzed the antagonism of tumor–macrophage bidirectional crosstalk on anticancer drugs.