ADM3, TFF3 and LGALS3 are discriminative molecular markers in fine-needle aspiration biopsies of benign and malignant thyroid tumours

Background:

Previously, we reported a six-marker gene set, which allowed a molecular discrimination of benign and malignant thyroid tumours. Now, we evaluated these markers in fine-needle aspiration biopsies (FNAB) in a prospective, independent series of thyroid tumours with proven histological outcome.

Methods:

Quantitative RT–PCR was performed (ADM3, HGD1, LGALS3, PLAB, TFF3, TG) in the needle wash-out of 156 FNAB of follicular adenoma (FA), adenomatous nodules, follicular and papillary thyroid cancers (TC) and normal thyroid tissues (NT).

Results:

Significant expression differences were found for TFF3, HGD1, ADM3 and LGALS3 in FNAB of TC compared with benign thyroid nodules and NT. Using two-marker gene sets, a specific FNAB distinction of benign and malignant tumours was achieved with negative predictive values (NPV) up to 0.78 and positive predictive values (PPV) up to 0.84. Two FNAB marker gene combinations (ADM3/TFF3; ADM3/ACTB) allowed the distinction of FA and malignant follicular neoplasia with NPV up to 0.94 and PPV up to 0.86.

Conclusion:

We demonstrate that molecular FNAB diagnosis of benign and malignant thyroid tumours including follicular neoplasia is possible with recently identified marker gene combinations. We propose multi-centre FNAB studies on these markers to bring this promising diagnostic tool closer to clinical practice.     

Epithelial-to-mesenchymal transition (EMT) induced by inflammatory priming elicits mesenchymal stromal cell-like immune-modulatory properties in cancer cells

Background:

Epithelial-to-mesenchymal transition (EMT) has a central role in cancer progression and metastatic dissemination and may be induced by local inflammation. We asked whether the inflammation-induced acquisition of mesenchymal phenotype by neoplastic epithelial cells is associated with the onset of mesenchymal stromal cell-like immune-regulatory properties that may enhance tumour immune escape.

Methods:

Cell lines of lung adenocarcinoma (A549), breast cancer (MCF7) and hepatocellular carcinoma (HepG2) were co-cultured with T, B and NK cells before and after EMT induction by either the supernatant of mixed-lymphocyte reactions or inflammatory cytokines.

Results:

EMT occurrence following inflammatory priming elicited multiple immune-regulatory effects in cancer cells resulting in NK and T-cell apoptosis, inhibition of lymphocyte proliferation and stimulation of regulatory T and B cells. Indoleamine 2,3-dioxygenase, but not Fas ligand pathway, was involved at least in part in these effects, as shown by the use of specific inhibitors.

Conclusions:

EMT induced by inflammatory stimuli confers to cancer cells some mesenchymal stromal cell-like immune-modulatory properties, which could be a cue for cancer progression and metastatic dissemination by favouring immune escape.     

CXCL9 induces chemotaxis, chemorepulsion and endothelial barrier disruption through CXCR3-mediated activation of melanoma cells

Background:

Metastasis is associated with poor prognosis for melanoma. The formation of metastases is a multi-step process, in which cancer cells can subsequently acquire the potential to intravasate into the blood or lymph vessels, disseminate through the circulation, extravasate through the endothelium and invade the connective tissue. There is increasing evidence that chemokines have a pivotal role in the dissemination and establishment of melanoma metastasis.

Methods:

We isolated melanoma cells from melanoma metastasis and performed different migration assays and transendothelial resistance measurements of endothelial monolayers co-cultured with melanoma cells, in order to monitor barrier function and diapedesis and confirmed these results by confocal microscopy.

Results:

We observed that tumour endothelial cells (ECs) secrete high levels of CXCL9 in all, and CXCL10 in most melanoma metastases. Migration studies revealed that low concentrations of these chemokines induce chemotaxis, whereas high concentrations induce spontaneous migration of melanoma cells (chemokinesis/chemorepulsion) and the disruption of the endothelial barrier, resulting in an accelerated transendothelial migration (TEM). Addition of anti-CXCL9 or anti-CXCR3 antibodies to the co-cultures delayed the TEM of melanoma cells.

Conclusion:

Our data represent novel mechanisms by which tumour cells in melanoma metastases might use the chemokine-expressing endothelium to leave the tumour and eventually to form additional metastases at distinct sites.     

Highly sensitive molecular diagnosis of prostate cancer using surplus material washed off from biopsy needles

Introduction:

Currently, final diagnosis of prostate cancer (PCa) is based on histopathological analysis of needle biopsies, but this process often bears uncertainties due to small sample size, tumour focality and pathologist''s subjective assessment.

Methods:

Prostate cancer diagnostic signatures were generated by applying linear discriminant analysis to microarray and real-time RT–PCR (qRT–PCR) data from normal and tumoural prostate tissue samples. Additionally, after removal of biopsy tissues, material washed off from transrectal biopsy needles was used for molecular profiling and discriminant analysis.

Results:

Linear discriminant analysis applied to microarray data for a set of 318 genes differentially expressed between non-tumoural and tumoural prostate samples produced 26 gene signatures, which classified the 84 samples used with 100% accuracy. To identify signatures potentially useful for the diagnosis of prostate biopsies, surplus material washed off from routine biopsy needles from 53 patients was used to generate qRT–PCR data for a subset of 11 genes. This analysis identified a six-gene signature that correctly assigned the biopsies as benign or tumoural in 92.6% of the cases, with 88.8% sensitivity and 96.1% specificity.

Conclusion:

Surplus material from prostate needle biopsies can be used for minimal-size gene signature analysis for sensitive and accurate discrimination between non-tumoural and tumoural prostates, without interference with current diagnostic procedures. This approach could be a useful adjunct to current procedures in PCa diagnosis.     

Frequency of HER2 expression of circulating tumour cells in patients with metastatic or recurrent gastrointestinal cancer

Background:

The clinical significance of circulating tumour cell (CTC) detection in gastrointestinal (GI) cancer remains controversial and the molecular biological characteristics of CTCs are poorly understood.

Methods:

A total of 87 patients with metastatic or recurrent GI cancer were prospectively enrolled. Circulating tumour cells and their HER2 status were assessed using the CellSearch System.

Results:

Among the 62 CTC-positive cases, we found 22 discordant cases (35.5%). Among the HER2-negative primary tumours, 17 of 54 developed HER2-positive CTCs. Five of eight had HER2-negative CTCs among the HER2-positive primary tumours.

Conclusion:

The findings in the current study suggest that it is critical to evaluate the HER2 status of not only the primary tumour but also the CTCs because the metastasising tumour cells are the primary target of systemic therapy.     

Identification of tumour-reactive lymphatic endothelial cells capable of inducing progression of gastric cancer

Background:

Tumour cells and stromal cells interact in the tumour microenvironment; moreover, stromal cells can acquire abnormalities that contribute to tumour progression. However, interactions between lymphatic endothelial cells (LECs) and tumour cells are largely unexamined. In this study, we aimed to determine whether tumour-specific LECs inhabit the tumour microenvironment and examine their influence on this microenvironment.

Methods:

We isolated normal LECs (NLECs) from a non-metastatic lymph node and tumour-associated LECs (TLECs) from cancerous lymph nodes. We examined proliferative and migratory potency, growth factor production, and gene expression of each type of LEC. Moreover, we developed a co-culture system to investigate the interactions between gastric cancer cells and LECs.

Results:

When compared with NLEC, TLECs had an abnormal shape, high proliferative and migratory abilities, and elevated expression of genes associated with inflammation, cell growth, and cell migration. NLECs co-cultured with gastric cancer cells from the OCUM12 cell line acquired TLEC-like phenotypes. Also, OCUM12 cells co-cultured with TLECs expressed high levels of genes responsible for metastasis.

Conclusions:

Our results demonstrated that LECs interacted with tumour cells and obtained abnormal phenotypes that could have important roles in tumour progression.     

Cisplatin plus paclitaxel and maintenance of bevacizumab on tumour progression, dissemination, and survival of ovarian carcinoma xenograft models

Background:

Bevacizumab is being incorporated as first-line therapy with standard-of-care chemotherapy on epithelial ovarian carcinoma (EOC). We investigated bevacizumab combined with chemotherapy on tumour progression and mouse survival in EOC xenograft models.

Methods:

Bevacizumab was administered concomitantly with cisplatin plus paclitaxel (DDP+PTX), continued after induction (maintenance) or started after chemotherapy. The effect on tumour progression was monitored by bioluminescence imaging (BLI) (1A9-luc xenograft). Tumour dissemination into the peritoneal organs and ascites formation (HOC22 xenograft) was evaluated by histological analysis at the end of treatment (interim) and at euthanasia (survival). The effects on overall survival (OS) were investigated in both EOC models.

Results:

Bevacizumab with PTX+DDP delayed tumour progression in mice bearing EOC xenografts. OS was significantly extended, with complete responses, by bevacizumab continued after stopping chemotherapy in the HOC22 xenograft. Bevacizumab alone inhibited ascites formation, with only limited effect on tumour burden, but combined with PTX+DDP reduced ascites and metastases. Bevacizumab started after induction with PTX+DDP and maintained was equally effective on tumour progression and survival on 1A9-luc xenograft.

Conclusion:

Bevacizumab combined with chemotherapy not only affected tumour progression, but when administered as maintenance regimen significantly prolonged survival, reducing ascites, and tumour dissemination. We believe our findings are consistent with the clinical results and shed light on the potential effects of this kind of treatment on tumour progression.     

Cytosine-based nucleoside analogs are selectively lethal to DNA mismatch repair-deficient tumour cells by enhancing levels of intracellular oxidative stress

Background:

DNA mismatch repair deficiency is present in a significant proportion of a number of solid tumours and is associated with distinct clinical behaviour.

Methods:

To identify the therapeutic agents that might show selectivity for mismatch repair-deficient tumour cells, we screened a pair of isogenic MLH1-deficient and MLH1-proficient tumour cell lines with a library of clinically used drugs. To test the generality of hits in the screen, selective agents were retested in cells deficient in the MSH2 mismatch repair gene.

Results:

We identified cytarabine and other related cytosine-based nucleoside analogues as being selectively toxic to MLH1 and MSH2-deficient tumour cells. The selective cytotoxicity we observed was likely caused by increased levels of cellular oxidative stress, as it could be abrogated by antioxidants.

Conclusion:

We propose that cytarabine-based chemotherapy regimens may represent a tumour-selective treatment strategy for mismatch repair-deficient cancers.     

Dissection of stromal and cancer cell-derived signals in melanoma xenografts before and after treatment with DMXAA

Background:

The non-malignant cells of the tumour stroma have a critical role in tumour biology. Studies dissecting the interplay between cancer cells and stromal cells are required to further our understanding of tumour progression and methods of intervention. For proof-of-principle of a multi-modal approach to dissect the differential effects of treatment on cancer cells and stromal cells, we analysed the effects of the stromal-targeting agent 5,6-dimethylxanthenone-4-acetic acid on melanoma xenografts.

Methods:

Flow cytometry and multi-colour immunofluorescence staining was used to analyse leukocyte numbers in xenografts. Murine-specific and human-specific multiplex cytokine panels were used to quantitate cytokines produced by stromal and melanoma cells, respectively. Human and mouse Affymetrix microarrays were used to separately identify melanoma cell-specific and stromal cell-specific gene expression.

Results:

5,6-Dimethylxanthenone-4-acetic acid activated pro-inflammatory signalling pathways and cytokine expression from both stromal and cancer cells, leading to neutrophil accumulation and haemorrhagic necrosis and a delay in tumour re-growth of 26 days in A375 melanoma xenografts.

Conclusion:

5,6-Dimethylxanthenone-4-acetic acid and related analogues may potentially have utility in the treatment of melanoma. The experimental platform used allowed distinction between cancer cells and stromal cells and can be applied to investigate other tumour models and anti-cancer agents.     

Ewing sarcoma dissemination and response to T-cell therapy in mice assessed by whole-body magnetic resonance imaging

Background:

Novel treatment strategies in Ewing sarcoma include targeted cellular therapies. Preclinical in vivo models are needed that reflect their activity against systemic (micro)metastatic disease.

Methods:

Whole-body magnetic resonance imaging (WB-MRI) was used to monitor the engraftment and dissemination of human Ewing sarcoma xenografts in mice. In this model, we evaluated the therapeutic efficacy of T cells redirected against the Ewing sarcoma-associated antigen G_D2 by chimeric receptor engineering.

Results:

Of 18 mice receiving intravenous injections of VH-64 Ewing sarcoma cells, all developed disseminated tumour growth detectable by WB-MRI. All mice had lung tumours, and the majority had additional manifestations in the bone, soft tissues, and/or kidney. Sequential scans revealed in vivo growth of tumours. Diffusion-weighted whole-body imaging with background signal suppression effectively visualised Ewing sarcoma growth in extrapulmonary sites. Animals receiving G_D2-targeted T-cell therapy had lower numbers of pulmonary tumours than controls, and the median volume of soft tissue tumours at first detection was lower, with a tumour growth delay over time.

Conclusion:

Magnetic resonance imaging reliably visualises disseminated Ewing sarcoma growth in mice. G_D2-retargeted T cells can noticeably delay tumour growth and reduce pulmonary Ewing sarcoma manifestations in this aggressive disease model.     

E-/P-selectins and colon carcinoma metastasis: first in vivo evidence for their crucial role in a clinically relevant model of spontaneous metastasis formation in the lung

Background:

Interactions of endothelial selectins with tumour cell glycoconjugates have been shown to have a major role in tumour cell dissemination in previous experiments. However, experiments validating this observation were limited in value, as ‘metastases'' in these experiments were artificially induced by i.v. injection rather than developed spontaneously as in true metastases.

Methods:

Endothelial (E) and platelet (P)-selectin-deficient severe combined immunodeficient (scid) mice were generated and human HT 29 colon cancer cells were subcutaneously inoculated in these mice and in wild-type scid mice. Tumour growth, spontaneous metastasis formation in the lung and adherence of HT29 cells to E- and P-selectin under flow were determined.

Results:

The number of metastases decreased by 84% in E- and P-selectin-deficient scid mice, compared with wild-type scid mice. The remaining 16% metastases in the E- and P-selectin-deficient scid mice grew within the pulmonary artery and not in the alveolar septae as they did in wild-type scid mice. Flow experiments indicate that tumour cells roll and tether on an E- and P-selectin matrix similar to leukocytes; however, firm adhesion is mainly mediated in E-selectin.

Conclusion:

Our results indicate that E- and P-selectins have a crucial role in spontaneous metastasis formation. As the human HT 29 colon cancer cells are positive for the lectin Helix pomatia agglutinin (HPA), which identified the metastatic phenotype in earlier clinical studies, these results are of particular clinical relevance.     

Pre-treatment with chemotherapy can enhance the antigenicity and immunogenicity of tumours by promoting adaptive immune responses

Background:

Some cancer patients are immuno-compromised, and it has been long felt that immune-intervention is not compatible with standard chemotherapies. However, increasing evidence suggests that standard chemotherapy drugs may stimulate beneficial changes in both the immune system and tumour.

Methods:

We have assessed the expression of human leucocyte antigen class 1 (HLA1) on tumour cells before and after chemotherapy agents (cyclophosphamide, oxaliplatin or gemcitabine). In addition, we show that chemotherapy-stressed tumour cells may release cytokines that enhance the interactions between dendritic cells (DCs) and T cells into growth media.

Results:

Here we report that some chemotherapy agents can increase HLA1 expression in tumour cells, even when expression is low. Increases were associated with killing by cytotoxic T cells, which were negated by HLA1-blockade. Furthermore, T-cell function, as indicated by increased proliferation, was enhanced as supernatants derived from tumours treated with chemotherapy augmented DC-maturation and function.

Conclusion:

There is evidence that a facet of immune surveillance can be restored by appropriate chemotherapy agents. Also, tumours exposed to some chemotherapy may secrete cytokines that can mature DCs, which ultimately enhances T-cell responses.     

Cold plasma selectivity and the possibility of a paradigm shift in cancer therapy

Background:

Plasma is an ionised gas that is typically generated in high-temperature laboratory conditions. However, recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature.

Methods:

Both in-vitro and in-vivo studies revealed that cold plasmas selectively kill cancer cells.

Results:

We show that: (a) cold plasma application selectively eradicates cancer cells in vitro without damaging normal cells; and (b) significantly reduces tumour size in vivo. It is shown that reactive oxygen species metabolism and oxidative stress responsive genes are deregulated.

Conclusion:

The development of cold plasma tumour ablation has the potential of shifting the current paradigm of cancer treatment and enabling the transformation of cancer treatment technologies by utilisation of another state of matter.     

The dynamic change of circulating tumour cells in patients with operable breast cancer before and after chemotherapy based on a multimarker QPCR platform

Background:

The possible presence of early tumour dissemination is the rationale behind the use of systemic adjuvant chemotherapy in patients with operable breast cancer. Circulating tumour cells (CTC) in peripheral blood may represent the possible presence of early tumour dissemination. However, relatively few studies were designed to investigate the relationship between the change of CTC status and the efficacy of adjuvant chemotherapy in operable breast cancer patients.

Methods:

In a prospective study, we established a multimarker real-time quantitative PCR platform to detect CTC in peripheral blood of breast cancer patients. By using this platform, we detected CTC in peripheral blood of 94 operable breast cancer patients. Control group consisted of 20 patients with benign breast disease and 20 healthy volunteers. For 72 patients who underwent systemic adjuvant chemotherapy, the dynamic CTC status at three different time points (1 day before initiation of chemotherapy, 1 week after three cycles of chemotherapy and 1 week after all cycles of chemotherapy) was observed.

Results:

Circulating tumour cells were detected in 56% (53 out of 94) of patients with operable breast cancer. The specificity was 95%. Seventy-two patients who received systemic adjuvant chemotherapy were followed up. After three cycles of chemotherapy, 47% (18 out of 38) of patients who were CTC-positive before chemotherapy changed into negative status. In addition, another 5% (2 out of 38) of patients had changed into negative status after all cycles of chemotherapy.

Conclusion:

Systemic adjuvant chemotherapy had a significant impact on CTC status, and this effect could be observed after three cycles of chemotherapy. Circulating tumour cells detection had the potential to be used to evaluate the efficacy of systemic adjuvant chemotherapy immediately after the chemotherapy was finished in operable breast cancer patients.     

Slice cultures from head and neck squamous cell carcinoma: a novel test system for drug susceptibility and mechanisms of resistance

Background:

Human head and neck squamous cell carcinoma (HNSCC) fundamentally vary in their susceptibility to different cytotoxic drugs and treatment modalities. There is at present no clinically accepted test system to predict the most effective therapy for an individual patient.

Methods:

Therefore, we established tumour-derived slice cultures which can be kept in vitro for at least 6 days. Upon treatment with cisplatin, docetaxel and cetuximab, slices were fixed and paraffin sections were cut for histopathological analysis.

Results:

Apoptotic fragmentation, activation of caspase 3, and cell loss were observed in treated tumour slices. Counts of nuclei per field in untreated compared with treated slices deriving from the same tumour allowed estimation of the anti-neoplastic activity of individual drugs on an individual tumour.

Conclusion:

HNSCC-derived slice cultures survive well in vitro and may serve not only to improve personalised therapies but also to detect mechanisms of tumour resistance by harvesting surviving tumour cells after treatment.     

IFN-γ from lymphocytes induces PD-L1 expression and promotes progression of ovarian cancer

Background:

PD-L1 (programmed cell death 1 ligand 1) on tumour cells suppresses host immunity through binding to its receptor PD-1 on lymphocytes, and promotes peritoneal dissemination in mouse models of ovarian cancer. However, how PD-L1 expression is regulated in ovarian cancer microenvironment remains unclear.

Methods:

The number of CD8-positive lymphocytes and PD-L1 expression in tumour cells was assessed in ovarian cancer clinical samples. PD-L1 expression and tumour progression in mouse models under conditions of altering IFN-γ signals was assessed.

Results:

The number of CD8-positive cells in cancer stroma was very high in peritoneally disseminated tumours, and was strongly correlated to PD-L1 expression on the tumour cells (P<0.001). In mouse models, depleting IFNGR1 (interferon-γ receptor 1) resulted in lower level of PD-L1 expression in tumour cells, increased the number of tumour-infiltrating CD8-positive lymphocytes, inhibition of peritoneal disseminated tumour growth and longer survival (P=0.02). The injection of IFN-γ into subcutaneous tumours induced PD-L1 expression and promoted tumour growth, and PD-L1 depletion completely abrogated tumour growth caused by IFN-γ injection (P=0.01).

Conclusions:

Interferon-γ secreted by CD8-positive lymphocytes upregulates PD-L1 on ovarian cancer cells and promotes tumour growth. The lymphocyte infiltration and the IFN-γ status may be the key to effective anti-PD-1 or anti-PD-L1 therapy in ovarian cancer.     

Angiogenesis and lymphangiogenesis are downregulated in primary breast cancer

Background:

Angiogenesis and lymphangiogenesis are considered to play key roles in tumour growth, progression and metastasis. However, targeting tumour angiogenesis in clinical trials showed only modest efficacy. We therefore scrutinised the concept of tumour angiogenesis and lymphangiogenesis by analysing the expression of crucial markers involved in these processes in primary breast cancer.

Methods:

We analysed the expression of angiogenic, lymphangiogenic or antiangiogenic factors, their respective receptors and specific markers for endothelial and lymphendothelial cells by quantitative real-time RT-PCR in primary breast cancer and compared the expression profiles to non-cancerous, tumour-adjacent tissues and breast tissues from healthy women.

Results:

We found decreased mRNA amounts of major angiogenic and lymphangiogenic factors in tumour compared to healthy tissues, whereas antiangiogenic factors were upregulated. Concomitantly, angiogenic and lymphangiogenic receptors were downregulated in breast tumours. This antiangiogenic, antilymphangiogenic microenvironment was even more pronounced in aggressive tumours and accompanied by reduced amounts of endothelial and lymphatic endothelial cell markers.

Conclusion:

Primary breast tumours are not a site of highly active angiogenesis and lymphangiogenesis. Selection for tumour cells that survive with minimal vascular supply may account for this observation in clinical apparent tumours.     

VEGF directly suppresses activation of T cells from ascites secondary to ovarian cancer via VEGF receptor type 2

Background:

Vascular endothelial growth factor action in tumour angiogenesis is well characterised; nevertheless, it functions as a key element in the promotion of the immune system''s evasion by tumours. We sought to investigate the possible direct effect of VEGF on T-cell activation and through which type of VEGF receptor it exerts this effect on cells isolated from ovarian cancer patients'' ascites.

Methods:

T cells isolated from the ascites of ovarian cancer patients were cultured with anti-CD3 and IL-2, with or without VEGF for 14 days and the number of viable T cells was counted. Cytotoxic activity of cultured T cells and expression of VEGF receptor-2 (VEGFR-2), was assayed.

Results:

The addition of VEGF in cultures significantly reduced the number and proliferation rate of T cells in a dose-dependent manner and CD3⁺ T cells expressed VEGFR-2 on their surface upon activation. Experiments with specific anti-VEGFR-2 antibodies revealed that the direct suppressive effect of VEGF on T-cell proliferation is mediated by VEGFR-2. We also showed that VEGF significantly reduced the cytotoxic activity of T cells.

Conclusion:

Our study showed that ascites-derived T cells secrete VEGF and express VEGFR-2 upon activation. Vascular endothelial growth factor directly suppresses T-cell activation via VEGFR-2.