Retrovirus-host interactions. The mouse mammary tumor virus model.

Mouse mammary tumor virus (MMTV) is a retrovirus which can induce mammary carcinomas in mice late in life by activation of proto-oncogenes after integration in their vicinity. Surprisingly, it requires a functional immune system to achieve efficient infection of the mammary gland. This requirement became clear when it was discovered that it has developed strategies to exploit the immune response. Instead of escaping immune detection, it induces a vigorous polyclonal T-B interaction which is required to induce a chronic infection. This is achieved by activating and then infecting antigen presenting cells (B cells), expressing a superantigen on their cell surface and triggering unlimited help by the large number of superantigen-specific T cells. The end result of this strong T-B interaction is the proliferation and differentiation of the infected B cells leading to their long term survival.

Treatment rationale and study design for a phase III, double-blind, placebo-controlled study of maintenance pemetrexed plus best supportive care versus best supportive care immediately following induction treatment with pemetrexed plus cisplatin for advanced nonsquamous non-small cell lung cancer.

BACKGROUND: To improve the efficacy of first-line therapy for advanced non-small cell lung cancer (NSCLC), additional maintenance chemotherapy may be given after initial induction chemotherapy in patients who did not progress during the initial treatment, rather than waiting for disease progression to administer second-line treatment. Maintenance therapy may consist of an agent that either was or was not present in the induction regimen. The antifolate pemetrexed is efficacious in combination with cisplatin for first-line treatment of advanced NSCLC and has shown efficacy as a maintenance agent in studies in which it was not included in the induction regimen. We designed a phase III study to determine if pemetrexed maintenance therapy improves progression-free survival (PFS) and overall survival (OS) after cisplatin/pemetrexed induction therapy in patients with advanced nonsquamous NSCLC. Furthermore, since evidence suggests expression levels of thymidylate synthase, the primary target of pemetrexed, may be associated with responsiveness to pemetrexed, translational research will address whether thymidylate synthase expression correlates with efficacy outcomes of pemetrexed. METHODS/DESIGN: Approximately 900 patients will receive four cycles of induction chemotherapy consisting of pemetrexed (500 mg/m2) and cisplatin (75 mg/m2) on day 1 of a 21-day cycle. Patients with an Eastern Cooperative Oncology Group performance status of 0 or 1 who have not progressed during induction therapy will randomly receive (in a 2:1 ratio) one of two double-blind maintenance regimens: pemetrexed (500 mg/m2 on day 1 of a 21-day cycle) plus best supportive care (BSC) or placebo plus BSC. The primary objective is to compare PFS between treatment arms. Secondary objectives include a fully powered analysis of OS, objective tumor response rate, patient-reported outcomes, resource utilization, and toxicity. Tumor specimens for translational research will be obtained from consenting patients before induction treatment, with a second biopsy performed in eligible patients following the induction phase. DISCUSSION: Although using a drug as maintenance therapy that was not used in the induction regimen exposes patients to an agent with a different mechanism of action, evidence suggests that continued use of an agent present in the induction regimen as maintenance therapy enables the identification of patients most likely to benefit from maintenance treatment.

“Unmixing” Tissue Gene Expression Signatures from Tumor Biopsies

Emergent molecular measurement methods, such as DNA microarray, qRTPCR, andmany others, offer tremendous promise for the personalized treatment of cancer. Thesetechnologies measure the amount of specific proteins, RNA, DNA or other moleculartargets from tumor specimens with the goal of “fingerprinting” individual cancers. Tumorspecimens are heterogeneous; an individual specimen typically contains unknownamounts of multiple tissues types. Thus, the measured molecular concentrations resultfrom an unknown mixture of tissue types, and must be normalized to account for thecomposition of the mixture.For example, a breast tumor biopsy may contain normal, dysplastic and cancerousepithelial cells, as well as stromal components (fatty and connective tissue) and bloodand lymphatic vessels. Our diagnostic interest focuses solely on the dysplastic andcancerous epithelial cells. The remaining tissue components serve to “contaminate”the signal of interest. The proportion of each of the tissue components changes asa function of patient characteristics (e.g., age), and varies spatially across the tumorregion. Because each of the tissue components produces a different molecular signature,and the amount of each tissue type is specimen dependent, we must estimate the tissuecomposition of the specimen, and adjust the molecular signal for this composition.Using the idea of a chemical mass balance, we consider the total measured concentrationsto be a weighted sum of the individual tissue signatures, where weightsare determined by the relative amounts of the different tissue types. We develop acompositional source apportionment model to estimate the relative amounts of tissuecomponents in a tumor specimen. We then use these estimates to infer the tissuespecificconcentrations of key molecular targets for sub-typing individual tumors. Weanticipate these specific measurements will greatly improve our ability to discriminatebetween different classes of tumors, and allow more precise matching of each patient tothe appropriate treatment

Giant proliferating trichilemmal malignant tumor

Proliferating trichilemmal cyst is a benign tumor that originates in the outer root sheath of hair follicle. Usually, it is located on the scalp in older women, but also have been reported in other sites such as back, chest, axilla, groin, gluteal region, thigh, vulva, and face. Malignant transformation of proliferating trichilemmal cyst is confirmed only on histological findings. This tumor has a variable biologic behavior with local recurrence and lymph node metastasis.

Demyelination induced by protein kinase C-activating tumor promoters in aggregating brain cell cultures.

The plasticity of mature oligodendrocytes was studied in aggregating brain cell cultures at the period of maximal expression of myelin marker proteins. The protein kinase C (PKC)-activating tumor promoters mezerein and phorbol 12-myristate 13-acetate (PMA), but not the inactive phorbol ester analog 4alpha-PMA, caused a pronounced decrease of myelin basic protein (MBP) content and 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) activity. In contrast, myelin/oligodendrocyte protein (MOG) content was affected relatively little. Northern blot analyses showed a rapid reduction of MBP and PLP gene expression induced by mezerein, and both morphological and biochemical findings indicate a drastic loss of compact myelin. During the acute phase of demyelination, only a relatively small increase in cell death was perceptible by in situ end labeling and in situ nick translation. Basic fibroblast growth factor (bFGF) also reduced the levels of the oligodendroglial differentiation markers and enhanced the demyelinating effects of the tumor promoters. The present results suggest that PKC activation resulted in severe demyelination and partial loss of the oligodendrocyte-differentiated phenotype.

Extranodal NK/T-Cell Lymphoma without Nasal Cavity Involvement Associated with Epstein-Barr Virus:AMultimodality-Based Diagnosis of Two Cases

We report two cases of extranodal NK/T-cell lymphoma, nasal type, in immunocompetent patients without nasal cavity involvement. In the two cases, the initial presumptive diagnosis was tuberculosis and there was a rapid dissemination of the tumor with short survival after the hospital admittance. An autopsy was performed showing infiltration in several organs including lymph nodes and mesenteric and retroperitoneal fat. Histological sections showed an angiocentric and angiodestructive growth pattern and the immunophenotype was CD45+, CD3+ (cytoplasmic), as well as Granzyme B+ and EBV+. However, CD56 expression was only positive in a case in which the molecular study showed T-cell gene rearrangement with monoclonal appearance and associated with hemophagocytic syndrome. These cases represent rare examples of NK/T-cell lymphoma disseminated outside the nasal cavity highly aggressive that lead to the rapid death of the patients.

The immunomodulator PSK induces in vitro cytotoxic activity in tumour cell linesvia arrest of cell cycle and induction of apoptosis

BACKGROUND Protein-bound polysaccharide (PSK) is derived from the CM-101 strain of the fungus Coriolus versicolor and has shown anticancer activity in vitro and in in vivo experimental models and human cancers. Several randomized clinical trials have demonstrated that PSK has great potential in adjuvant cancer therapy, with positive results in the adjuvant treatment of gastric, esophageal, colorectal, breast and lung cancers. These studies have suggested the efficacy of PSK as an immunomodulator of biological responses. The precise molecular mechanisms responsible for its biological activity have yet to be fully elucidated. METHODS The in vitro cytotoxic anti-tumour activity of PSK has been evaluated in various tumour cell lines derived from leukaemias, melanomas, fibrosarcomas and cervix, lung, pancreas and gastric cancers. Tumour cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of PSK on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in PSK-treated cells. RESULTS PSK showed in vitro inhibition of tumour cell proliferation as measured by BrdU incorporation and viable cell count. The inhibition ranged from 22 to 84%. Inhibition mechanisms were identified as cell cycle arrest, with cell accumulation in G0/G1 phase and increase in apoptosis and caspase-3 expression. These results indicate that PSK has a direct cytotoxic activity in vitro, inhibiting tumour cell proliferation. In contrast, PSK shows a synergistic effect with IL-2 that increases PBL proliferation. CONCLUSION These results indicate that PSK has cytotoxic activity in vitro on tumour cell lines. This new cytotoxic activity of PSK on tumour cells is independent of its previously described immunomodulatory activity on NK cells.

Breast cancer suppressor candidate-1 (BCSC-1) is a melanoma tumor suppressor that down regulates MITF.

Understanding the molecular aberrations involved in the development and progression of metastatic melanoma (MM) is essential for a better diagnosis and targeted therapy. We identified breast cancer suppressor candidate-1 (BCSC-1) as a novel tumor suppressor in melanoma. BCSC-1 expression is decreased in human MM, and its ectopic expression in MM-derived cell lines blocks tumor formation in vivo and melanoma cell proliferation in vitro while increasing cell migration. We demonstrate that BCSC-1 binds to Sox10, which down regulates MITF, and results in a switch of melanoma cells from a proliferative to a migratory phenotype. In conclusion, we have identified BCSC-1 as a tumor suppressor in melanoma and as a novel regulator of the MITF pathway.

Late pulmonary metastases of renal cell carcinoma immediatelyafter post-transplantation immunosuppressive treatment: a case report

INTRODUCTION We report a case of pulmonary metastatic recurrence of renal adenocarcinoma soon after radical nephrectomy that was followed by renal transplant and immunosuppressive medication. Increased risk of metastatic recurrence of renal cell carcinoma should be considered in the immediate post-transplant period when immunosuppressive medication is administered, even if nephrectomy had been performed many years earlier. CASE PRESENTATION In 1986 the patient demonstrated renal insufficiency secondary to mesangial glomerulonephritis. In 1992 he underwent left side radical nephrectomy with histopathological diagnosis of clear cell adenocarcinoma. Mesangial glomerulonephritis in the remaining right kidney progressed to end-stage renal failure. In October 2000 he received a kidney transplant from a cadaver and commenced immunosuppressive medication. Two months later, several nodules were found in his lungs, which were identified as metastases from the primary renal tumor that had been removed with the diseased kidney 8 years earlier. CONCLUSION Recurrence of renal cell carcinoma metastases points to tumor dormancy and reflects a misbalance between effective tumor immune surveillance and immune escape. This case demonstrates that a state of tumor dormancy can be interrupted soon after administration of immunosuppressant medication.

Distinct mechanisms of loss of IFN-gamma mediated HLA class I inducibility in two melanoma cell lines

BACKGROUND The inability of cancer cells to present antigen on the cell surface via MHC class I molecules is one of the mechanisms by which tumor cells evade anti-tumor immunity. Alterations of Jak-STAT components of interferon (IFN)-mediated signaling can contribute to the mechanism of cell resistance to IFN, leading to lack of MHC class I inducibility. Hence, the identification of IFN-gamma-resistant tumors may have prognostic and/or therapeutic relevance. In the present study, we investigated a mechanism of MHC class I inducibility in response to IFN-gamma treatment in human melanoma cell lines. METHODS Basal and IFN-induced expression of HLA class I antigens was analyzed by means of indirect immunofluorescence flow cytometry, Western Blot, RT-PCR, and quantitative real-time RT-PCR (TaqMan(R) Gene Expression Assays). In demethylation studies cells were cultured with 5-aza-2'-deoxycytidine. Electrophoretic Mobility Shift Assay (EMSA) was used to assay whether IRF-1 promoter binding activity is induced in IFN-gamma-treated cells. RESULTS Altered IFN-gamma mediated HLA-class I induction was observed in two melanoma cells lines (ESTDAB-004 and ESTDAB-159) out of 57 studied, while treatment of these two cell lines with IFN-alpha led to normal induction of HLA class I antigen expression. Examination of STAT-1 in ESTDAB-004 after IFN-gamma treatment demonstrated that the STAT-1 protein was expressed but not phosphorylated. Interestingly, IFN-alpha treatment induced normal STAT-1 phosphorylation and HLA class I expression. In contrast, the absence of response to IFN-gamma in ESTDAB-159 was found to be associated with alterations in downstream components of the IFN-gamma signaling pathway. CONCLUSION We observed two distinct mechanisms of loss of IFN-gamma inducibility of HLA class I antigens in two melanoma cell lines. Our findings suggest that loss of HLA class I induction in ESTDAB-004 cells results from a defect in the earliest steps of the IFN-gamma signaling pathway due to absence of STAT-1 tyrosine-phosphorylation, while absence of IFN-gamma-mediated HLA class I expression in ESTDAB-159 cells is due to epigenetic blocking of IFN-regulatory factor 1 (IRF-1) transactivation.

Open partial nephrectomy in renal cancer: a feasible gold standard technique in all hospitals

Introduction. Partial nephrectomy (PN) is playing an increasingly important role in localized renal cell carcinoma (RCC) as a true alternative to radical nephrectomy. With the greater experience and expertise of surgical teams, it has become an alternative to radical nephrectomy in young patients when the tumor diameter is 4 cm or less in almost all hospitals since cancer-specific survival outcomes are similar to those obtained with radical nephrectomy. Materials and Methods. The authors comment on their own experience and review the literature, reporting current indications and outcomes including complications. The surgical technique of open partial nephrectomy is outlined. Conclusions. Nowadays, open PN is the gold standard technique to treat small renal masses, and all nonablative techniques must pass the test of time to be compared to PN. It is not ethical for patients to undergo radical surgery just because the urologists involved do not have adequate experience with PN. Patients should be involved in the final treatment decision and, when appropriate, referred to specialized centers with experience in open or laparoscopic partial nephrectomies

REPETIDO_A new extract of the plant calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation

BACKGROUND Phytopharmacological studies of different Calendula extracts have shown anti-inflammatory, anti-viral and anti-genotoxic properties of therapeutic interest. In this study, we evaluated the in vitro cytotoxic anti-tumor and immunomodulatory activities and in vivo anti-tumor effect of Laser Activated Calendula Extract (LACE), a novel extract of the plant Calendula Officinalis (Asteraceae). METHODS An aqueous extract of Calendula Officinalis was obtained by a novel extraction method in order to measure its anti-tumor and immunomodulatory activities in vitro. Tumor cell lines derived from leukemias, melanomas, fibrosarcomas and cancers of breast, prostate, cervix, lung, pancreas and colorectal were used and tumor cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of LACE on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in LACE-treated cells. In vivo anti-tumor activity was evaluated in nude mice bearing subcutaneously human Ando-2 melanoma cells. RESULTS The LACE extract showed a potent in vitro inhibition of tumor cell proliferation when tested on a wide variety of human and murine tumor cell lines. The inhibition ranged from 70 to 100%. Mechanisms of inhibition were identified as cell cycle arrest in G0/G1 phase and Caspase-3-induced apoptosis. Interestingly, the same extract showed an opposite effect when tested on PBLs and NKL cell line, in which in vitro induction of proliferation and activation of these cells was observed. The intraperitoneal injection or oral administration of LACE extract in nude mice inhibits in vivo tumor growth of Ando-2 melanoma cells and prolongs the survival day of the mice. CONCLUSION These results indicate that LACE aqueous extract has two complementary activities in vitro with potential anti-tumor therapeutic effect: cytotoxic tumor cell activity and lymphocyte activation. The LACE extract presented in vivo anti-tumoral activity in nude mice against tumor growth of Ando-2 melanoma cells.

Clinicobiological progression and prognosis of oral squamous cell carcinoma in relation to the tumor invasive front: impact on prognosis

CONCLUSION: There are several factors that influence the final outcome when treating oral squamous cell carcinoma (OSCC). Invasive front phenomena and more importantly their clinicopathological translation can have a direct impact on survival, and subsequently on the decision for an adjuvant treatment. OBJECTIVES: In recent years, the concept of tumor-host interaction has been the subject of substantial efforts in cancer research. Tumoral behavior may be better understood when studying the changes occurring at the tumor-host interface. This study evaluated the influence of several clinicopathological features on the outcome of OSCCs. METHODS: The clinical records and pathology specimens of 54 patients with OSCC treated by primary resection were reviewed retrospectively. The pathologic features reviewed were: invasive front grading (IFG), stromal reaction, lymphovascular invasion (LVI), perineural invasion (PNI), margin status, and depth of invasion. RESULTS: High IFGs had a significant relationship with pT status and pN status. High IFGs were strongly correlated with nodal metastases (odds ratio (OR) = 4.77; confidence interaval (CI) = 1.37-16.64). Concerning survival, IFG had a strong impact on disease-free survival in patients treated unimodally, as did the depth of invasion in the same group. Lymphovascular involvement was found to have a negative impact on overall survival in patients treated multimodally.

Tumor architecture exerts no bias on nuclear grading in breast cancer diagnosis.

We recently reported that nuclear grading in prostate cancer is subject to a strong confirmation bias induced by the tumor architecture. We now wondered whether a similar bias governs nuclear grading in breast carcinoma. An unannounced test was performed at a pathology conference. Pathologists were asked to grade nuclei in a PowerPoint presentation. Circular high power fields of 27 invasive ductal carcinomas were shown, superimposed over low power background images of either tubule-rich or tubule-poor carcinomas. We found (a) that diagnostic reproducibility of nuclear grades was poor to moderate (weighed kappa values between 0.07 and 0.54, 27 cases, 44 graders), but (b) that nuclear grades were not affected by the tumor architecture. We speculate that the categorized grading in breast cancer, separating tubule formation, nuclear pleomorphism, and mitotic figure counts in a combined three tier score, prevents the bias that architecture exerts on nuclear grades in less well-controlled situations.

Involvement of microglia-neuron interactions in the tumor necrosis factor-alpha release, microglial activation, and neurodegeneration induced by trimethyltin.

Trimethyltin (TMT) is a neurotoxicant known to induce early microglial activation. The present study was undertaken to investigate the role played by these microglial cells in the TMT-induced neurotoxicity. The effects of TMT were investigated in monolayer cultures of isolated microglia or in neuron-enriched cultures and in neuron-microglia and astrocyte-microglia cocultures. The end points used were morphological criteria; evaluation of cell death and cell proliferation; and measurements of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and nitric oxide (NO) release in culture supernatant. The results showed that, in cultures of microglia, TMT (10(-6) M) caused, after a 5-day treatment, an increased release of TNF-alpha, without affecting microglial shape or cell viability. When microglia were cocultured with astrocytes, TNF-alpha release was decreased to undetectable levels. In contrast, in neuron-microglia cocultures, TNF-alpha levels were found to increase at lower concentrations of TMT (i.e., 10(-8) M). Moreover, at 10(-6) M of TMT, microglia displayed further morphological activation, as suggested by process retraction and by decrease in cell size. No morphological activation was observed in cultures of isolated microglial cells and in astrocyte-microglia cocultures. With regard to neurons, 10(-6) M of TMT induced about 30% of cell death, when applied to neuron-enriched cultures, whereas close to 100% of neuronal death was observed in neuron-microglia cocultures. In conclusion, whereas astrocytes may rather dampen the microglial activation by decreasing microglial TNF-alpha production, neuronal-microglial interactions lead to enhanced microglial activation. This microglial activation, in turn, exacerbates the neurotoxic effects of TMT. TNF-alpha may play a major role in such cell-cell communications.