Vaccimel immunization is associated with enhanced response to treatment with anti-PD-1 monoclonal antibodies in cutaneous melanoma patients - a case reports study.

Cancer vaccines are gaining ground as immunotherapy options. We have previously demonstrated in cutaneous melanoma (CM) patients that adjuvant treatment with VACCIMEL, a mixture of four irradiated CM cell lines co-adjuvanted with BCG and GM-CSF, increases the cellular immune response to melanocyte differentiation antigens, cancer-testis antigens and neoantigens, with respect to basal levels. On the other hand, it is also known that treatment with anti-PD-1 monoclonal antibodies (MAbs), acting on pre-existing tumor-reactive lymphocytes, induces clinical responses in CM patients, albeit in a fraction of treated patients. A combination of both treatments would appear therefore desirable. In this paper, we describe CM patients who, having progressed even years after vaccination, were treated with anti-PD-1 MAbs. In 5/5 of such progressor patients, complete responses were obtained which lasted between 3 and 65+ months. Three of the patients remain disease-free and two recurred. One of the patients passed away after a recurrence of brain metastases. We suggest that clonally expanded reactive lymphocytes induced by VACCIMEL partially remain as memory cells, which may be recalled after tumor recurrence and may foster ulterior activity of anti-PD-1 MAbs.

HEV-associated dendritic cells are observed in metastatic tumor-draining lymph nodes of cutaneous melanoma patients with longer distant metastasis-free survival after adjuvant immunotherapy.

Introduction: Tissue biomarkers that aid in identifying cutaneous melanoma (CM) patients who will benefit from adjuvant immunotherapy are of crucial interest. Metastatic tumor-draining lymph nodes (mTDLN) are the first encounter site between the metastatic CM cells and an organized immune structure. Therefore, their study may reveal mechanisms that could influence patients´ outcomes. Methods: Twenty-nine stage-III CM patients enrolled in clinical trials to study the vaccine VACCIMEL were included in this retrospective study. After radical mTDLN dissection, patients were treated with VACCIMEL (n=22) or IFNα-2b (n=6), unless rapid progression (n=1). Distant Metastasis-Free Survival (DMFS) was selected as an end-point. Two cohorts of patients were selected: one with a good outcome (GO) (n=17; median DMFS 130.0 months), and another with a bad outcome (BO) (n=12; median DMFS 8.5 months). We analyzed by immunohistochemistry and immunofluorescence the expression of relevant biomarkers to tumor-cell biology and immune cells and structures in mTDLN, both in the tumor and peritumoral areas. Results: In BO patients, highly replicating Ki-67+ tumor cells, low tumor HLA-I expression and abundant FoxP3+ lymphocytes were found (p=0.037; p=0.056 and p=0.021). In GO patients, the most favorable biomarkers for prolonged DMFS were the abundance of peri- and intra-tumoral CD11c+ cells (p=0.0002 and p=0.001), peri-tumoral DC-LAMP+ dendritic cells (DCs) (p=0.001), and PNAd+ High Endothelial Venules (HEVs) (p=0.004). Most strikingly, we describe in GO patients a peculiar, heterogeneous structure that we named FAPS (Favoring Antigen-Presenting Structure), a triad composed of DC, HEV and CD62L+ naïve lymphocytes, whose postulated role would be to favor tumor antigen (Ag) priming of incoming naïve lymphocytes. We also found in GO patients a preferential tumor infiltration of CD8+ and CD20+ lymphocytes (p=0.004 and p=0.027), as well as peritumoral CD20+ aggregates, with no CD21+ follicular dendritic cells detected (p=0.023). Heterogeneous infiltration with CD64+CD68-CD163-, CD64+CD68+CD163- and CD64+CD68+CD163+ macrophages were observed in both cohorts. Discussion: The analysis of mTDLN in GO and BO patients revealed marked differences. This work highlights the importance of analyzing resected mTDLN from CM patients and suggests a correlation between tumor and immune characteristics that may be associated with a spontaneous or vaccine-induced long DMFS. These results should be confirmed in prospective studies.

An Update of Cutaneous Melanoma Patients Treated in Adjuvancy With the Allogeneic Melanoma Vaccine VACCIMEL and Presentation of a Selected Case Report With In-Transit Metastases.

The CSF-470 vaccine (VACCIMEL) plus BCG and GM-CSF as adjuvants has been assayed in cutaneous melanoma patients. In the adjuvant randomized Phase II study CASVAC-0401, vaccinated patients had longer distant metastasis-free survival (DMFS) than those treated with IFNα2b. Five years after locking the data, an actualization was performed. The benefit in DMFS was maintained in the vaccinated group versus the IFNα2b-treated group (p = 0.035), with a median DMFS of 96 months for VACCIMEL and 13 months for IFNα2b. The favorable risk-benefit ratio was maintained. DMFS was also analyzed as a single cohort in all the IIB, IIC, and III patients (n = 30) who had been treated with VACCIMEL. The median DMFS was 169 months, and at 48 months follow-up, it was 71.4%, which was not statistically different from DMFS of previously published results obtained in adjuvancy with ipilimumab, pembrolizumab, nivolumab, or dabrafenib/trametinib. The possible toxicity of combining VACCIMEL with anti-immune checkpoint inhibitors (ICKi) was analyzed, especially since VACCIMEL was co-adjuvated with BCG in every vaccination. A patient with in-transit metastases was studied to produce a proof of concept. During treatment with VACCIMEL, the patient developed T-cell clones reactive towards tumor-associated antigens. Three years after ending the VACCIMEL study, the patient progressed and was treated with ICKi. During ICKi treatment, the patient did not reveal any toxicity due to previous BCG treatment. When she recurred after a 4-year treatment with nivolumab, a biopsy was obtained and immunohistochemistry and RNA-seq were performed. The tumor maintained expression of tumor-associated antigens and HLA-I and immune infiltration, with immunoreactive and immunosuppressive features. VACCIMEL plus BCG and GM-CSF is an effective treatment in adjuvancy for stages IIB, IIC, and III cutaneous melanoma patients, and it is compatible with subsequent treatments with ICKi.

The Transcriptomic Portrait of Locally Advanced Breast Cancer and Its Prognostic Value in a Multi-Country Cohort of Latin American Patients.

Purposes: Most molecular-based published studies on breast cancer do not adequately represent the unique and diverse genetic admixture of the Latin American population. Searching for similarities and differences in molecular pathways associated with these tumors and evaluating its impact on prognosis may help to select better therapeutic approaches. Patients and Methods: We collected clinical, pathological, and transcriptomic data of a multi-country Latin American cohort of 1,071 stage II-III breast cancer patients of the Molecular Profile of Breast Cancer Study (MPBCS) cohort. The 5-year prognostic ability of intrinsic (transcriptomic-based) PAM50 and immunohistochemical classifications, both at the cancer-specific (OSC) and disease-free survival (DFS) stages, was compared. Pathway analyses (GSEA, GSVA and MetaCore) were performed to explore differences among intrinsic subtypes. Results: PAM50 classification of the MPBCS cohort defined 42·6% of tumors as LumA, 21·3% as LumB, 13·3% as HER2E and 16·6% as Basal. Both OSC and DFS for LumA tumors were significantly better than for other subtypes, while Basal tumors had the worst prognosis. While the prognostic power of traditional subtypes calculated with hormone receptors (HR), HER2 and Ki67 determinations showed an acceptable performance, PAM50-derived risk of recurrence best discriminated low, intermediate and high-risk groups. Transcriptomic pathway analysis showed high proliferation (i.e. cell cycle control and DNA damage repair) associated with LumB, HER2E and Basal tumors, and a strong dependency on the estrogen pathway for LumA. Terms related to both innate and adaptive immune responses were seen predominantly upregulated in Basal tumors, and, to a lesser extent, in HER2E, with respect to LumA and B tumors. Conclusions: This is the first study that assesses molecular features at the transcriptomic level in a multicountry Latin American breast cancer patient cohort. Hormone-related and proliferation pathways that predominate in PAM50 and other breast cancer molecular classifications are also the main tumor-driving mechanisms in this cohort and have prognostic power. The immune-related features seen in the most aggressive subtypes may pave the way for therapeutic approaches not yet disseminated in Latin America. Clinical Trial Registration: ClinicalTrials.gov (Identifier: NCT02326857).

Estudio exploratorio retrospectivo/prospectivo para establecer perfil inmunológico en pacientes de cáncer de mama / Retrospective/prospective exploratory study to establish immunological profile in breast cancer patients

Se evaluó el perfil inmunológico en una cohorte de 300 muestras retrospectivas de pacientes que asistieron al HIGA Eva Perón de San Martín. El análisis fenotípico de los infiltrados leucocitarios analizados y de la expresión de moléculas de los puntos de control del sistema inmune se evaluó en estroma, el microambiente y epitelio tumoral. Las muestras se categorizaron en función de la expresión de los receptores de estrógeno, progesterona, Her2-neu y Ki67. La sobrevida (120 meses) fue significativamente mayor para el grupo molecular 1 (73,3%), mientras que para el grupo 2 fue de 66% y para las HER2+ fue del 52,9%. El grupo basal o de pacientes triple negativas presentó menor sobrevida con un 35,4%. Las células mayoritarias CD68+ fueron un 48,8% en los tumores del grupo 4 y los linfocitosCD8+ (26-28%). Los linfocitos T regulatorios, asociados con mal pronóstico, presentaron una tendencia al aumento a medida que se avanza de grado molecular, llegando ≈15% en el grupo 4. Los linfocitos CD20+ están más representados en el grupo 4 (10,52%). Del análisis exploratorio de la expresión de moléculas inhibitorias de control inmunitario se desprende que la expresión de TIM-3 en el microambiente de los tumores del grupo 1 está significativamente aumentada, señalando una población de linfocitos disfuncionales. Se observó expresión de PDL-1 y PDL-2, ligandos de PD1 en células tumorales de todos los grupos. La correlación entre los ligandos con los linfocitos PD1+ se hizo más importante en términos de Rs y significancia a medida que el grado molecular aumenta. BST-2 presentó una mayor expresión en epitelio tumoral y en los tumores Her-2+ se observó mayor señal estromal, asociadas con mal pronóstico en cáncer de mama. Durante el proyecto de un año se expandió el Biobanco con 1193 muestras (incluye tumor en congelación pareado con suero, plasma, ADN circulante), que en futuros proyectos permitirá completar la caracterización del perfil inmunológico del presente proyecto. La plataforma de datos y muestras recolectadas es un material inapreciable para futuras investigaciones.

Evaluation of T-Cell Responses Against Shared Melanoma Associated Antigens and Predicted Neoantigens in Cutaneous Melanoma Patients Treated With the CSF-470 Allogeneic Cell Vaccine Plus BCG and GM-CSF.

The CSF-470 vaccine consists of lethally-irradiated allogeneic cells derived from four cutaneous melanoma cell lines administered plus BCG and GM-CSF as adjuvants. In an adjuvant phase II study vs. IFN-α2b, the vaccine significantly prolonged the distant metastasis-free survival (DMFS) of stages IIB-IIC-III melanoma patients with evidence of the induction of immune responses against vaccine cells. Purpose: The aim of this study was to analyze the antigens against which the immune response was induced, as well as the T-helper profile and lytic ability of immune cells after CSF-470 treatment. Methods: HLA-restricted peptides from tumor-associated antigens (TAAs) were selected from TANTIGEN database for 13 evaluable vaccinated patients. In addition, for patient #006 (pt#006), tumor somatic variants were identified by NGS and candidate neoAgs were selected by predicted HLA binding affinity and similarity between wild type (wt) and mutant peptides. The patient's PBMC reactivity against selected peptides was detected by IFNγ-ELISPOT. T-helper transcriptional profile was determined by quantifying GATA-3, T-bet, and FOXP3 mRNA by RT-PCR, and intracellular cytokines were analyzed by flow cytometry. Autologous tumor cell lysis by PBMC was assessed in an in vitro calcein release assay. Results: Vaccinated patient's PBMC reactivity against selected TAAs derived peptides showed a progressive increase in the number of IFNγ-producing cells throughout the 2-yr vaccination protocol. ELISPOT response correlated with delayed type hypersensitivity (DTH) reaction to CSF-470 vaccine cells. Early upregulation of GATA-3 and Foxp3 mRNA, as well as an increase in CD4+IL4+cells, was associated with a low DMFS. Also, IFNγ response against 9/73 predicted neoAgs was evidenced in the case of pt#006; 7/9 emerged after vaccination. We verified in pt# 006 that post-vaccination PBMC boosted in vitro with the vaccine lysate were able to lyse autologous tumor cells. Conclusions: A progressive increase in the immune response against TAAs expressed in the vaccine and in the patient's tumor was induced by CSF-470 vaccination. In pt#006, we demonstrated immune recognition of patient's specific neoAgs, which emerged after vaccination. These results suggest that an initial response against shared TAAs could further stimulate an immune response against autologous tumor neoAgs.

Immunization With the CSF-470 Vaccine Plus BCG and rhGM-CSF Induced in a Cutaneous Melanoma Patient a TCRß Repertoire Found at Vaccination Site and Tumor Infiltrating Lymphocytes That Persisted in Blood.

The CSF-470 cellular vaccine plus BCG and rhGM-CSF increased distant metastases-free survival in cutaneous melanoma patients stages IIB-IIC-III relative to medium dose IFN-α2b (CASVAC-0401 study). Patient-045 developed a mature vaccination site (VAC-SITE) and a regional cutaneous metastasis (C-MTS), which were excised during the protocol, remaining disease-free 36 months from vaccination start. CDR3-TCRß repertoire sequencing in PBMC and tissue samples, along with skin-DTH score and IFN-γ ELISPOT assay, were performed to analyze the T-cell immune response dynamics throughout the immunization protocol. Histopathological analysis of the VAC-SITE revealed a highly-inflamed granulomatous structure encircled by CD11c+ nested-clusters, brisk CD8+ and scarce FOXP3+, lymphocytes with numerous Langhans multinucleated-giant-cells and macrophages. A large tumor-regression area fulfilled the C-MTS with brisk lymphocyte infiltration, mainly composed of CD8+PD1+ T-cells, CD20+ B-cells, and scarce FOXP3+ cells. Increasing DTH score and IFN-γ ELISPOT assay signal against the CSF-470 vaccine-lysate was evidenced throughout immunization. TCRß repertoire analysis revealed for the first time the presence of common clonotypes between a VAC-SITE and a C-MTS; most of them persisted in blood by the end of the immunization protocol. In vitro boost with vaccine-lysate revealed the expansion of persistent clones that infiltrated the VAC-SITE and/or the C-MTS; other persistent clones expanded in the patient's blood as well. We propose that expansion of such persistent clonotypes might derive from two different although complementary mechanisms: the proliferation of specific clones as well as the expansion of redundant clones, which increased the number of nucleotide rearrangements per clonotype, suggesting a functional antigenic selection. In this patient, immunization with the CSF-470 vaccine plus BCG and rhGM-CSF induced a T-cell repertoire at the VAC-SITE that was able to infiltrate an emerging C-MTS, which resulted in the expansion of a T-cell repertoire that persisted in blood by the end of the 2-year treatment.

Peripheral changes in immune cell populations and soluble mediators after anti-PD-1 therapy in non-small cell lung cancer and renal cell carcinoma patients.

Patients with non-small cell lung cancer (NSCLC) and renal cell carcinoma (RCC) have shown benefit from anti-PD-1 therapies. However, not all patients experience tumor shrinkage, durable responses or prolonged survival, demonstrating the need to find response markers. In blood samples from NSCLC and RCC patients obtained before and after anti-PD-1 treatment, we studied leukocytes by complete blood cell count, lymphocyte subsets using flow cytometry and plasma concentration of nine soluble mediators, in order to find predictive biomarkers of response and to study changes produced after anti-PD-1 therapy. In baseline samples, discriminant analysis revealed a combination of four variables that helped differentiate stable disease-response (SD-R) from progressive disease (PD) patients: augmented frequency of central memory CD4+ T cells and leukocyte count was associated with response while increased percentage of PD-L1+ natural killer cells and naïve CD4+ T cells was associated with lack of response. After therapy, differential changes between responders and non-responders were found in leukocytes, T cells and TIM-3+ T cells. Patients with progressive disease showed an increase in the frequency of TIM-3 expressing CD4+ and CD8+ T cells, whereas SD-R patients showed a decrease in these subsets. Our findings indicate that a combination of immune variables from peripheral blood (PB) could be useful to distinguish response groups in NSCLC and RCC patients treated with anti-PD-1 therapy. Frequency of TIM-3+ T cells showed differential changes after treatment in PD vs SD-R patients, suggesting that it may be an interesting marker for monitoring progression during therapy.

Changes in the TCRß Repertoire and Tumor Immune Signature From a Cutaneous Melanoma Patient Immunized With the CSF-470 Vaccine: A Case Report.

The allogeneic therapeutic vaccine CSF-470 has demonstrated a significant benefit over medium-dose IFNα2b in the distant metastasis-free survival for stages IIB-IIC-III cutaneous melanoma patients in a randomized phase II/III clinical trial (CASVAC-0401, NCT01729663). At the end of the 2-year CSF-470 immunization protocol, patient #006 developed several lung and one subcutaneous melanoma metastases; this later was excised. In this report, we analyzed the changes throughout vaccination of immune populations in blood and in the tumor tissue, with special focus on the T-cell repertoire. Immunohistochemistry revealed a marked increase in CD8+, CD4+, and CD20+ lymphocytes infiltrating the metastasis relative to the primary tumor. Lymphocytes were firmly attached to dying-tumor cells containing Granzyme-B granules. Whole-exon sequencing assessment indicated a moderate-to-high tumor mutational burden, with BRAFV600E as the main oncogenic driver. Mutational signature presented large numbers of mutations at dipyrimidines, typical of melanoma. Relevant tumor and immune-related genes from the subcutaneous metastasis were addressed by RNA-Seq analysis, revealing expression of typical melanoma antigens and proliferative tumor-related genes. Stimulatory and inhibitory immune transcripts were detected as well as evidence of active T-cell effector function. Peripheral blood monitoring revealed an increase in CD4+ and CD8+ cells by the end of the immunization protocol. By CDR3-T-cell receptor ß (TCRß) sequencing, generation of new clones and an increase in oligoclonality was observed in the peripheral T-cells immune repertoire throughout immunization. A shift, with the expansion of selected preexisting and newly arising clones with reduction of others, was detected in blood. In tumor-infiltrating lymphocytes, prevalent clones (50%) were both new and preexisting that were expanded in blood following CSF-470 immunization. These clones persisted in time, since 2 years after completing the immunization, 51% of the clones present in the metastasis were still detected in blood. This is the first report of the modulation of the TCRß repertoire from a melanoma patient immunized with the CSF-470 vaccine. After immunization, the changes observed in peripheral immune populations as well as in the tumor compartment suggest that the vaccine can induce an antitumor adaptive immune repertoire that can reach tumor lesions and persists in blood for at least 2 years.

Phase II Study of Adjuvant Immunotherapy with the CSF-470 Vaccine Plus Bacillus Calmette-Guerin Plus Recombinant Human Granulocyte Macrophage-Colony Stimulating Factor vs Medium-Dose Interferon Alpha 2B in Stages IIB, IIC, and III Cutaneous Melanoma Patients: A Single Institution, Randomized Study.

The irradiated, allogeneic, cellular CSF-470 vaccine plus Bacillus Calmette-Guerin (BCG) and recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) is being tested against medium-dose IFN-α2b in stages IIB-III cutaneous melanoma (CM) patients (pts) after surgery in an open, randomized, Phase II/III study. We present the results of the Phase II part of the ongoing CASVAC-0401 study (ClinicalTrials.gov: NCT01729663). Thirty-one pts were randomized to the CSF-470 vaccine (n = 20) or to the IFN-α2b arm (n = 11). During the 2-year treatment, immunized pts should receive 13 vaccinations. On day 1 of each visit, 1.6 × 107 irradiated CSF-470 cells plus 106 colony-forming units BCG plus 100 µg rhGM-CSF were administered intradermally, followed on days 2-4 by 100 µg rhGM-CSF. IFN-α2b pts should receive 10 million units (MU)/day/5 days a week for 4 weeks; then 5 MU thrice weekly for 23 months. Toxicity and quality of life (QOL) were evaluated at each visit. With a mean and a maximum follow-up of 39.4 and 83 months, respectively, a significant benefit in the distant metastasis-free survival (DMFS) for CSF-470 was observed (p = 0.022). Immune monitoring showed an increase in antitumoral cellular and humoral response in vaccinated pts. CSF-470 was well tolerated; 20/20 pts presented grades 1-2 dermic reactions at the vaccination site; 3/20 pts presented grade 3 allergic reactions. Other adverse events (AEs) were grade 1. Pts in the IFN-α2b arm presented grades 2-3 hematological (7/11), hepatic (2/11), and cardiac (1/11) toxicity; AEs in 9/11 pts forced treatment interruptions. QOL was significantly superior in the vaccine arm (p < 0.0001). Our results suggest that CSF-470 vaccine plus BCG plus GM-CSF can significantly prolong, with lower toxicity, the DMFS of high-risk CM pts with respect to medium-dose IFN-α2b. The continuation of a Phase III part of the CASVAC-0401 study is encouraged.

Metallothionein 1G promotes the differentiation of HT-29 human colorectal cancer cells.

Metallothioneins (MTs) are a family of low-molecular-weight, cysteine-rich proteins involved in zinc and redox metabolism, that are epigenetically downregulated during colorectal cancer (CRC) progression, but may be re-induced with a variety of agents. Since loss of MT expression is associated with a worse prognosis, in the present study we investigated the effects of overexpression of the most significantly downregulated isoform in CRC, namely MT1G, on the HT-29 cell line. Overexpression of MT1G resulted in xenograft tumors with an aberrant morphology, characterized by an evident increase in mucin-containing cells that were identified as goblet cells under electron microscopy. Immunohistochemical detection of CDX2 and cytokeratin 20 was also increased, as were goblet­cell and enterocyte-specific genes by qRT-PCR. Microarray analysis of gene expression confirmed the alteration of several differentiation signaling pathways, including the Notch pathway. Using sodium butyrate and post-confluent growth as inducers of differentiation, we demonstrated that MT1G does indeed play a functional role in promoting goblet over enterocyte differentiation in vitro. Labile zinc is also induced upon differentiation of CRC cells, functionally contributing to enterocyte over goblet differentiation, as revealed using zinc­specific chelating agents. Overall, our results uncover a new tumor-suppressor activity of MT1G in promoting the differentiation of at least some CRC tumors, and implicate MTs and zinc signaling as new players in colorectal differentiation. This further contributes to the hypothesis that re-induction of MTs may have therapeutic value by diminishing the aggressiveness of CRC tumors.

Inoculation site from a cutaneous melanoma patient treated with an allogeneic therapeutic vaccine: a case report.

We have developed a therapeutic vaccine consisting of a mixture of lethally-irradiated allogeneic cutaneous melanoma cell lines with BCG and GM-CSF as adjuvants. The CSF-470 vaccine is currently being assayed in a Phase II-III trial against medium-dose IFN-α2b. All vaccinated patients immunized intradermally developed large edematous erythema reactions, which then transformed into subcutaneous nodules active for several months. However, vaccine injection sites were not routinely biopsied. We describe the case of a female patient, previously classified as stage III, but who, due to the simultaneous discovery of bone metastases only received one vaccination was withdrawn from the study, and continued her treatment elsewhere. This patient developed a post-vaccination nodule which was surgically removed 7 weeks later, and allowed to analyze the reactivity and immune profiling of the inoculation site. An inflammatory reaction with zones of fibrosis, high irrigation, and brisk lymphoid infiltration, primarily composed of CD8(+) and CD20(+) lymphocytes, was observed. There were no remaining BCG bacilli, and scarce CD4(+) and Foxp3(+) T cells were determined. MART-1 Ag was found throughout the vaccination site. CD11c(+) Ag presenting cells were either dispersed or forming dense nests. Some CD11c(+) cells proliferated; most of them contained intracellular MART-1 Ag, and some interacted with CD8(+) lymphocytes. These observations suggest a potent, long-lasting local inflammatory response with recruitment of Ag-presenting cells that incorporate melanoma Ags, probably leading to Ag presentation to naïve T cells.

CD207⁺ cells recruitment to the vaccination site and draining lymph nodes after the administration of DC-Apo/Nec vaccine in mice.

De novo ectopic lymphoid tissue formation is known to occur in certain disease and inflammatory settings. After an effective vaccination with dendritic cells (DC) charged with melanoma apoptotic/necrotic cells (Apo/Nec), a subcutaneous tertiary lymphoid structure was organized, where retained vaccine cells interacted with recruited inflammatory and T cells. In this work we report for the first time the recruitment of two morphologically different CD207(+) cells to vaccination site. The time-course behavior of CD207(+) cells was reciprocal between vaccination site and draining lymph nodes (DLNs). After 6-10 days, CD207(+) cells localized at the paracortical region of DLNs, in close contact with T cell population. DLNs were enriched in a peculiar MHCII(+) CD11c((-)) CD207(+) population, whose role remains to be determined. Whether CD207(+) cells migration to the vaccination site can be associated with a differential anti-tumoral response remains as an open and exciting question.

Protein expression changes during human triple negative breast cancer cell line progression to lymph node metastasis in a xenografted model in nude mice.

Triple negative breast cancers (TNBC) lacking hormone receptors and HER-2 amplification are very aggressive tumors. Since relevant differences between primary tumors and metastases could arise during tumor progression as evidenced by phenotypic discordances reported for hormonal receptors or HER-2 expression, in this analysis we studied changes that occurred in our TNBC model IIB-BR-G throughout the development of IIB-BR-G-MTS6 metastasis to the lymph nodes (LN) in nude mice, using an antibody-based protein array to characterize their expression profile. We also analyzed their growth kinetics, migration, invasiveness and cytoskeleton structure in vitro and in vivo. In vitro IIB-BR-G-MTS6 cells grew slower but showed higher anchorage independent growth. In vivo IIB-BR-G-MTS6 tumors grew significantly faster and showed a 100% incidence of LN metastasis after s.c. inoculation, although no metastasis was observed for IIB-BR-G. CCL3, IL1ß, CXCL1, CSF2, CSF3, IGFBP1, IL1α, IL6, IL8, CCL20, PLAUR, PlGF and VEGF were strongly upregulated in IIB-BR-G-MTS6 while CCL4, ICAM3, CXCL12, TNFRSF18, FIGF were the most downregulated proteins in the metastatic cell line. IIB-BR-G-MTS6 protein expression profile could reflect a higher NFκB activation in these cells. In vitro, IIB-BR-G displayed higher migration but IIB-BR-G-MTS6 had more elevated matrigel invasion ability. In agreement with that observation, IIB-BR-G-MTS6 had an upregulated expression of MMP1, MMP9, MMP13, PLAUR and HGF. IIB-BR-G-MTS6 tumors presented also higher local lymphatic invasion than IIB-BR-G but similar lymphatic vessel densities. VEGFC and VEGFA/B expression were higher both in vitro and in vivo for IIB-BR-G-MTS6. IIB-BR-G-MTS6 expressed more vimentin than IB-BR-G cells, which was mainly localized in the cellular extremities and both cell lines are E-cadherin negative. Our results suggest that IIB-BR-G-MTS6 cells have acquired a pronounced epithelial-to-mesenchymal transition phenotype. Protein expression changes observed between primary tumor-derived IIB-BR-G and metastatic IIB-BR-G-MTS6 TNBC cells suggest potential targets involved in the control of metastasis.

Metallothionein expression in colorectal cancer: relevance of different isoforms for tumor progression and patient survival.

Metallothioneins are a family of small, cysteine-rich proteins with many functions. Immunohistochemical evaluation of all metallothionein 1 + 2 isoforms in colorectal tumors has demonstrated an important down-regulation compared with normal tissue, although its prognostic significance is unclear. Moreover, the contribution of individual isoforms to overall metallothionein down-regulation is not known. To address these important issues, we analyzed the messenger RNA expression levels of all functional metallothionein 1 + 2 isoforms by quantitative reverse transcription polymerase chain reaction in 22 pairs of normal and tumor-microdissected epithelia and correlated these to the overall immunohistochemical protein expression. Our results showed that 5 isoforms (MT1G, 1E, 1F, 1H, and 1M) were lost during the transition from normal mucosa to tumor, whereas MT1X and MT2A were less down-regulated, and their expression was correlated with overall protein positivity. Second, we showed that MT1G hypermethylation occurred in cell lines and in 29% of tumor samples, whereas histone deacetylase inhibitors are able to induce most isoforms. Furthermore, we analyzed by immunohistochemistry 107 normal mucosae, 25 adenomas, 81 carcinomas, and 19 lymph node metastases to evaluate metallothionein expression during different stages of cancer development and to assess its relationship to patient survival. A lower immunohistochemical expression was associated with poorer survival, although it was not an independent predictor. Overall, this study identifies for the first time the relevant metallothionein isoforms for colorectal cancer progression, supports the concept that their loss is associated with worse prognosis, and suggests 2 mechanisms for epigenetic repression of metallothionein expression in colorectal tumors.

Human leukocyte antigen-E protein is overexpressed in primary human colorectal cancer.

HLA-E is a non-classical MHC molecule whose expression by tumour cells has been recently reported in several human cancer types. We studied HLA-E expression in colorectal cancer patients, its clinical significance and prognostic value, as well as characterized its expression in colorectal cancer cell lines. We analysed HLA-E expression at the transcript level by qRT-PCR in micro-dissected samples and at the protein level by semiquantitative immunohistochemistry on paraffin-embedded tissue sections from 42 biopsies of colorectal cancer patients. We observed that HLA-E transcript and protein are spontaneously overexpressed in a significant proportion of colorectal tumour biopsies, as compared to normal mucosae. We also found a negative correlation between HLA-E expression and the CD57+ cells infiltrate. Moreover, we analysed HLA-E expression in several colorectal cancer cell lines and demonstrated that IFN-gamma upregulates the expression of membrane HLA-E in vitro. Interestingly, we demonstrated that colorectal cancer cell lines overexpressing HLA-E at the cell surface inhibited NK-mediated cell lysis. Although IFN-gamma regulatory role needs further investigation, we provide evidence suggesting that this cytokine, within the tumour microenvironment, could promote HLA-E translocation to the surface of tumour epithelial cells. Furthermore, we showed that upregulation of HLA-E could be a marker of shorter disease-free survival in Dukes' C patients and we suggest that this molecule renders tumours less susceptible to immune attack.

La proteína quimiotratante de monocitos correlaciona con la angiogénesis en melanomas metastásicos / Monocyte chemoattractante protein correlates with angiogenesis in metastatic melanoma

Se analizaron biopsias de melanoma metastásico humano para elucidar la relación entre la expresión de la quimioquina MCP-1/CCL2 (monocyte chemoattractant protein-1), la angiogénesis y la agrasividad del tumor. Se encontró que esta quimioquina se expresa en el 100% de los casos, con heterogeneidad en el porcentaje de células positivas dentro del tumor. Estos tumores presentaron gran cantidad de macrófagos infiltrantes, particularmente asociados a las áreas de mas activa angiogénesis. Se obtuvo correlación positiva entre el porcentaje de células que expresan MCP-1 y el grado de vascularización. Asimismo, se encontró asociación entre una mayor angiogénesis y la proliferación tumoral evaluada como índice mitótico. Estos resultados sugieren que el aumento en la vascularización podría ser predictivo de metástasis más agresivas, donde la expresión de MCP-1 estaría estrechamente vinculada al desarrollo de vasos a través del reclutamiento de macrófagos.

Galectin-3 expression correlates with apoptosis of tumor-associated lymphocytes in human melanoma biopsies.

The immune system recognizes diverse melanoma antigens. However, tumors can evade the immune response, therefore growing and progressing. It has been reported that galectin-3 and galectin-1 can induce apoptosis of activated lymphocytes. However, there is strong evidence indicating that the regulation of galectins function in the human tumor microenvironment is a complex process that is influenced by diverse biological circumstances. Here, we have investigated 33 biopsies (eight primary and 25 metastases) from 24 melanoma patients (15-72 years old) and describe the correlation between the expression of galectin-3 or galectin-1 and the level of apoptosis of tumor-associated lymphocytes using immunohistochemistry and an in situ nick translation assay. The range of galectin-3-positive tumor cells varied between 0% and 93% and that of galectin-1-positive tumor cells varied between 5% and 97%. In addition, 23 +/- 27% of tumor-associated lymphocytes were apoptotic. Although our results show a correlation between galectin-3 expression and apoptosis of tumor-associated lymphocytes, we could not find such correlation with galectin-1. Considering the complex process of cancer immunoediting, various interacting factors must be considered.