Thymic stromal lymphopoietin in human pancreatic ductal adenocarcinoma: expression and prognostic significance

Thymic stromal lymphopoietin (TSLP) has emerged as an important, but contradictory, player conditioning tumor growth. In certain contexts, by driving T helper (h) 2 responses via tumor-associated OX40 Ligand (OX40L)⁺ dendritic cells (DCs), TSLP may play a pro-tumorigenic role. The study elucidates the importance of TSPL in pancreatic ductal adenocarcinoma (PDAC), by analyzing: i) TSLP levels in PDAC cell-line supernatants and plasma from patients with locally-advanced/metastatic PDAC, pre- and post-treatment with different chemotherapeutic protocols, in comparison with healthy donors; ii) TSLP and OX40L expression in PDAC and normal pancreatic tissues, by immunohistochemistry; iii) OX40L expression on ex vivo-generated normal DCs in the presence of tumor-derived TSLP, by flow cytometry; iv) clinical relevance in terms of diagnostic and prognostic value and influence on treatment modality and response.

Some PDAC cell lines, such as BxPC-3, expressed both TSLP mRNA and protein. Normal DCs, generated ex vivo in the presence of TSLP-rich-cell supernatants, displayed increased expression of OX40L, reduced by the addition of a neutralizing anti-TSLP polyclonal antibody. OX40L⁺ cells were detected in pancreatic tumor inflammatory infiltrates. Abnormally elevated TSLP levels were detected in situ in tumor cells and, systemically, in locally-advanced/metastatic PDAC patients. Of the chemotherapeutic protocols applied, gemcitabine plus oxaliplatin (GEMOX) significantly increased circulating TSLP levels. Elevated plasma TSLP concentration was associated with shorter overall survival and increased risk of poor outcome. Plasma TSLP measurement successfully discriminated PDAC patients from healthy controls.

These data show that TSLP secreted by pancreatic cancer cells may directly impact PDAC biology and patient outcome.

N-Ras Mutations in Myeloid Leukemias

The presence of mutations activating the N-ras gene was investigated by the polymerase chain reaction technique in twenty patients with acute myeloblastic leukemia (AML) at onset and in four patients with Ph' positive chronic myelogeneous leukemia (CML) either in chronic phase or in blast crisis. Four remission samples and four relapses from the AML cases were also studied. Mutations were found in five out of twenty (25%) untreated AML cases at onset. No mutations were detected in the complete remission samples, two of them with N-ras mutations during the leukemic phase. Two out of the four leukemia relapses were positive for the same N-ras mutation shown at presentation, whereas no new mutations were found in the other two initially negative cases. An N-ras mutation appeared during the blast crisis of one of the four CML, which were all negative during the chronic phase. In conclusion, whereas some data appear to be consistent with a role of the N-ras mutations as initiating events in myeloid leukemias, in other cases N-ras activation seems to represent a factor involved in progression. These data suggest that a partial overlapping between initiation and progression factors could exist in naturally occurring tumors.

Capecitabine with/without mitomycin C: results of a randomized phase II trial of second-line therapy in advanced biliary tract adenocarcinoma

PURPOSE

Advanced biliary tract adenocarcinoma (BTA) is a rare tumor with a poor prognosis. Since no standard salvage chemotherapy regimen exists, we explored the activity of capecitabine alone or combined with mitomycin C.

METHODS

Patients aged 18-75 years and with KPS >50, with pathological diagnosis of BTA stratified based on site and stage of disease, were randomized to receive capecitabine 2000 mg/m(2) day 1-14 alone (ARM A) or in combination with mitomycin C 6 mg/m(2) day 1 (ARM B) as second-line therapy. Cycles were repeated in both arms every 3 weeks. Tumor assessment was performed every 2 months. The primary endpoint was the probability of being progression free at 6 months (PFS-6) from treatment start. According to the Fleming design, the study aimed to enroll 26 pts per arm. An exploratory endpoint was to assess thymidylate synthase (TS) and thymidine phosphorylase (TP) expression, as biomarkers predictive for clinical outcomes of capecitabine treatment.

RESULTS

Between October 2011 and 2013, 57 metastatic pts were enrolled: ARM A/B 28/29. Accordingly, 55 (26/29) pts were assessable for the primary endpoint: 2 (8%) ARM A and 3 (10%) ARM B pts were PFS-6. Main G3-4 toxicities were: hand-foot syndrome and transaminitis in 4/0%, and thrombocytopenia, diarrhea and fatigue in 0/3% of pts. No statistically significant correlation was found between TS or TP expression and pts' outcome.

CONCLUSIONS

Since capecitabine yielded a disappointing outcome and the addition of mitomycin C did not improve the results, new therapeutic strategies need to be explored to improve survival in this disease setting.

Chimeric rat/human HER2 efficiently circumvents HER2 tolerance in cancer patients

PURPOSE

Despite the great success of HER2 vaccine strategies in animal models, effective clinical results have not yet been obtained. We studied the feasibility of using DNA coding for chimeric rat/human HER2 as a tool to break the unresponsiveness of T cells from patients with HER2-overexpressing tumors (HER2-CP).

EXPERIMENTAL DESIGN

Dendritic cells (DCs) generated from patients with HER2-overexpressing breast (n = 28) and pancreatic (n = 16) cancer were transfected with DNA plasmids that express human HER2 or heterologous rat sequences in separate plasmids or as chimeric constructs encoding rat/human HER2 fusion proteins and used to activate autologous T cells. Activation was evaluated by IFN-γ ELISPOT assay, perforin expression, and ability to halt HER2+ tumor growth in vivo.

RESULTS

Specific sustained proliferation and IFN-γ production by CD4 and CD8 T cells from HER2-CP was observed after stimulation with autologous DCs transfected with chimeric rat/human HER2 plasmids. Instead, T cells from healthy donors (n = 22) could be easily stimulated with autologous DCs transfected with any human, rat, or chimeric rat/human HER2 plasmid. Chimeric HER2-transfected DCs from HER2-CP were also able to induce a sustained T-cell response that significantly hindered the in vivo growth of HER2(+) tumors. The efficacy of chimeric plasmids in overcoming tumor-induced T-cell dysfunction relies on their ability to circumvent suppressor effects exerted by regulatory T cells (Treg) and/or interleukin (IL)-10 and TGF-β1.

CONCLUSIONS

These results provide the proof of concept that chimeric rat/human HER2 plasmids can be used as effective vaccines for any HER2-CP with the advantage of being not limited to specific MHC. Clin Cancer Res; 20(11); 2910-21. ©2014 AACR.

Pancreatic-carcinoma-cell-derived pro-angiogenic factors can induce endothelial-cell differentiation of a subset of circulating CD34+ progenitors

Background

CD34⁺ progenitor cells comprise both hematopoietic and endothelial progenitor cells. Recent studies suggest that circulating endothelial progenitor cells are recruited into the angiogenic vascular system of several cancers, including pancreatic carcinoma, and that they correlate with clinical progress. However, whether endothelial progenitor cell mobilization occurs in response to cytokine release by tumor cells is still unclear.

Methods

The chemotactic- and/or differentiating-activities of the poorly-differentiated pancreatic carcinoma cell line PT45, and of the immortal H6c7 cell line, a line of near-normal pancreatic duct epithelial cells, on endothelial progenitor cells were investigated in vitro using circulating CD34⁺ as model.

Results

The study showed that Vascular Endothelial Growth Factor produced by PT45 cells and, at lesser extent, by H6c7 cells, predominantly chemoattract peripheral blood CD34⁺ expressing the type 2 relative receptor. Addition of PT45-conditioned medium to CD34⁺ cells, cultured under conditions supporting myeloid cell development, diverted the differentiation of a subset of these progenitor cells into cells expressing endothelial cell markers, such as CD146, CD105, VE-cadherin and von Willebrand Factor-related antigen. Moreover, these endothelial-like cells formed capillary networks in vitro, chiefly through the release of Angiopoietin-1 by PT45 cells.

Conclusions

The results demonstrate that pancreatic-carcinoma cells potentially attract circulating endothelial progenitor cells to the tumor site, by releasing high levels of pro-angiogenic factors such as Vascular Endothelial Growth Factor and Angiopoietin-1, and may direct the differentiation of these cell subsets of the CD34⁺ cell population into endothelial cells; the latter cells may become a component of the newly-formed vessels, contributing to angiogenesis-mediated tumor growth and metastasis.

Maintenance sunitinib or observation in metastatic pancreatic adenocarcinoma: a phase II randomised trial

BACKGROUND

New strategies to prolong disease control warrant investigation in patients with metastatic pancreatic adenocarcinoma. This open-label, randomised, multi-centre phase II trial explored the role of maintenance sunitinib after first-line chemotherapy in this setting.

METHODS

Patients with pathologic diagnosis of metastatic pancreatic adenocarcinoma, performance status >50%, no progression after 6 months of chemotherapy were centrally randomised by an independent contract research organisation, which was also responsible for data collection and monitoring, to observation (arm A) or sunitinib at 37.5mg daily until progression or a maximum of 6 months (arm B). The primary outcome measure was the probability of being progression-free at 6 months (PFS-6) from randomisation. Assuming P0 = 10%; P1 = 30%, α .10; β .10, the target accrual was 26 patients per arm.

RESULTS

28 per arm were randomised. One arm B patient had kidney cancer and was excluded. Sunitinib was given for a median of 91 days (7-186). Main grade 3-4 toxicity was thrombocytopenia, neutropenia and hand-foot syndrome (12%), diarrhoea 8%. In arm A versus B, PFS-6 was 3.6% (95% confidence interval (CI): 0-10.6%) and 22.2% (95% CI: 6.2-38.2%; P<0.01); 2 y overall survival was 7.1% (95% CI: 0-16.8%) and 22.9% (95% CI: 5.8-40.0%; P = 0.11), stable disease 21.4% and 51.9% (P = 0.02).

CONCLUSION

This is the first randomised trial on maintenance therapy in metastatic pancreatic adenocarcinoma. The primary end-point was fulfilled and 2 y overall survival was remarkably high, suggesting that maintenance sunitinib is promising and should be further explored in this patient population.

Maintenance sunitinib (MS) or observation (O) in metastatic pancreatic adenocarcinoma (MPA): Clinical and translational results of a phase II randomized trial (NCT00967603)

4017

Background: Combination chemotherapy (CT) prolonged progression-free survival at 6 months (PFS6) of patients (pts) with MPA from <20% with gemcitabine (GEM) to >50%. To prolong CT over 6 months has unproven benefit and is hampered by cumulative toxicity. This open-label, randomised, multi-centre phase II trial explored the role of MS in pts with MPA without progressive disease (PD) after CT, using an O group as calibration arm. The role of circulating endothelial cells (CEC) as biomarker of MS activity was explored. Methods: Adult pts with pathologic diagnosis of MPA, performance status (PS) >50%, without radiological PD or CA19.9 raise >20% after 6 months of CT were stratified based on PS and previous CT and randomized to O (arm A) or MS at 37.5 mg daily until PD or a maximum of 6 months (arm B). Primary endpoint was PFS6. Sample size (H0 10%; H1 30%; a .10; b .10) was 26 pts per arm and MS had to be considered of interest with >5 pts PFS6. CEC were evaluated by flow cytofluorometry on a baseline peripheral blood sample. Results: 56 pts (29 arm A; 27 arm B) were enrolled. One arm B pt had kidney cancer and was excluded. Pts characteristics were (A/B): median age 64/61 years; median PS 90/100; median CA19.9 45/32; previous CT: GEM 3/3; combination CT 26/22. Main grade 3-4 toxicity in arm B was 15% neutropenia; 12% thrombocytopenia and hand-foot syndrome, 8% diarrhea. Second line CT was given to 76% of pts in both arms. One arm A (3%) and 6 arm B pts (23%; p=.01) were PFS6; 2y overall survival (OS) was 4% and 25% (p=.09). Blood sample for CEC analysis was available for 46 of 55 pts (84%). In arm A, median PFS was longer for pts with CEC number <30 (lower terzile group) when compared to >30 (2.9 versus 1.9 months; p.08). MS significantly increased PFS in CEC >30 group (3.4 months; p=.01). No PFS difference between arms was observed in <30 group (2.3 months). Conclusions: This is the first randomized trial on maintenance therapy in MPA. In arm B, the primary endpoint was fulfilled and 2y OS was remarkably high, suggesting that MS may have a role in pts with MPA. The number of CEC may be useful to predict benefit from MS.

Potential plasticity of T regulatory cells in pancreatic carcinoma in relation to disease progression and outcome

CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) are understood to maintain peripheral tolerance to self-antigens and inhibit antitumor immune responses. However, compelling evidence suggests that, Tregs provide no anti-inflammatory protection in the tumor microenvironment, but rather contribute to a T helper 17 (Th17)-driven pro-carcinogenic process. Using three-color flow cytometry, we evaluated the percentage of circulating CD4(+)CD25(+)FoxP3(+) Tregs in the peripheral blood of pancreatic carcinoma patients prior to and after chemotherapy [gemcitabine (GEM) alone, or GEM+oxaliplatin (GEMOX) or bevacizumab+capecitabine+radiotherapy (BEV+CAPE+RT)]. Correlations were sought between Treg counts and plasma levels of cytokines relevant to controlling the Treg/Th17 balance, i.e., interleukin (IL)-23, IL-17A, IL-6 and transforming growth factor β 1 (TGF-β1), as measured by ELISA and the clinical features of pancreatic cancer. Treg, IL-6 and TGF-β1 levels were higher in locally advanced and metastatic pancreatic carcinoma patients compared to controls. No parameter was correlated with disease stage except IL-6. IL-17A and TGF-β1 were significantly associated with increased risk of poor prognosis. IL-17A was positively correlated with IL-23. Treg and IL-6 levels decreased following GEM monochemotherapy, IL-17A levels decreased after GEMOX, and IL-6 levels were reduced subsequent to BEV+CAPE+RT treatment. IL-23, IL-17A and TGF-β1 levels were significantly lower in patients responding to chemotherapy (partial remission/stable disease) than in nonresponders to chemotherapy (progressive disease). These results suggest an impact of the Treg/Th17-balance in pancreatic carcinoma, highlighting the significance of TGF-β1 and IL-17A as potential prognostic and predictive indicators. Immunological changes induced by mono and/or combined chemotherapy indicate specific windows of opportunity for introducing integrative interventions on a new target in pancreatic cancer, i.e. IL-17A, possibly improving survival in this highly lethal disease.

Comparative evaluation of cancer stem cell markers in normal pancreas and pancreatic ductal adenocarcinoma

Chemoresistance and self-renewal of cancer stem cells (CSC), found in many tumors including pancreatic ductal adenocarcinoma (PDAC), are believed to underlie tumor mass regrowth. The distribution of cells carrying the putative stem-cell markers CD133, Nestin, Notch1-4, Jagged1 and 2, ABCG2 and aldehyde dehydrogenase (ALDH1) was assessed immunohistochemically using PDAC and normal pancreas tissue microarrays. The immunoreactivity was semi-quantitatively graded against the normal pancreas and was correlated with the differentiation grade and disease stage. No statistical significant differences were found between normal pancreas and PDAC in the expression of Nestin, Notch1, 3 and 4, ABCG2 or ALDH1. Notch2 and Jagged1 and 2 expression were increased in PDAC. CD133-positive cells were above-normal in PDAC, but the difference was not statistically significant. Nestin, Notch1-4, Jagged1, ABCG2 and ALDH1 immunostaining scores were not correlated with tumor grade or disease stage. CD133 and Notch2 expression was significantly inversely correlated with tumor grade, but not disease stage. Notch3 immunostaining positively correlated with tumor stage, but not with differentiation grade. Jagged2 protein expression correlated inversely with disease stage, but not with tumor grade. From the clinical standpoint, improved delineation of the tumor CSC signature, putatively responsible for tumor initiation and recurrence after initial response to chemotherapy, may offer novel therapeutic targets for this highly lethal cancer.

Pilot study to relate clinical outcome in pancreatic carcinoma and angiogenic plasma factors/circulating mature/progenitor endothelial cells: Preliminary results

Circulating endothelial cells (CEC) and bone marrow-derived endothelial progenitors (ECP) play important roles in tumor growth and have been proposed as non-invasive markers of angiogenesis. However, CEC and ECP levels have not been investigated in pancreatic carcinoma patients. Using four-color flow cytometry procedures, we evaluated the count of resting (rCEC) and activated (aCEC) endothelial cells and ECP in the peripheral blood of pancreatic carcinoma patients before and after chemotherapy, consisting of gemcitabine (GEM) alone or in combination with oxaliplatin (OX), or with 5-fluorouracil (5-FU). We also correlated CEC and ECP levels with plasma levels of relevant angiogenic factors, such as vascular endothelial growth factor (VEGF)-A, VEGF-D, angiopoietin (Angio)-1, and chemokine C-X-C motif ligand (CXCL)12, measured by ELISA, and with clinical features of pancreatic cancer. The aCEC, rCEC, ECP, and VEGF-A plasma levels were significantly higher in locally-advanced and metastatic patients than controls. Both ECP and VEGF-A levels correlated positively with disease stage and inversely with patient's overall survival. Measurements after the treatment course showed that VEGF-A plasma concentrations and ECP counts had decreased significantly. In particular, VEGF-A and rCEC were significantly down after treatment with GEM alone or in combination with OX. No significant differences in terms of circulating angiogenic factor or endothelial cell subtype levels were found between responders (patients entering partial remission or with stable disease) and non-responders (patients with progressive disease). The study provides insights into angiogenesis mechanisms in pancreatic carcinoma, for which anti-angiogenic targeting of VEGF-A and ECP could be of interest.

Circulating autoantibodies to phosphorylated α-enolase are a hallmark of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis and no diagnostic markers have, as of yet, been defined. In PDAC patients, α-enolase (ENOA) is up-regulated and elicits the production of autoantibodies. Here, we analyzed the autoantibody response to post-translational modifications of ENOA in PDAC patients. ENOA isolated from PDAC tissues and cell lines was characterized by two-dimensional electrophoresis (2-DE) Western blot (WB), revealing the expression of six different isoforms (named ENOA1,2,3,4,5,6) whereas only 4 isoforms (ENOA3,4,5,6) were detectable in normal tissues. As assessed by 2-DE WB, 62% of PDAC patients produced autoantibodies to the two more acidic isoforms (ENOA1,2) as opposed to only 4% of controls. Mass spectrometry showed that ENOA1,2 isoforms were phosphorylated on serine 419. ROC analysis demonstrated that autoantibodies to ENOA1,2 usefully complement the diagnostic performance of serum CA19.9 levels, achieving approximately 95% diagnostic accuracy in both advanced and resectable PDAC. Moreover, the presence of autoantibodies against ENOA1,2 correlated with a significantly better clinical outcome in advanced patients treated with standard chemotherapy. In conclusion, our results demonstrate that ENOA phosphorylation is associated with PDAC and induces specific autoantibody production in PDAC patients that may have diagnostic value.

Impact of surgery and chemotherapy on cellular immunity in pancreatic carcinoma patients in view of an integration of standard cancer treatment with immunotherapy

As surgery and chemotherapy may act as adjuvants providing antitumor immunity benefits, we ran phenotypical and functional immunomonitoring in patients with resectable pancreatic adenocarcinoma and advanced metastatic disease receiving combined treatment (cisplatin, gemcitabine, 5-FU). Blood was taken before/one month after resection; before/during chemotherapy. Controls were age- and gender-matched. Circulating lymphocyte, myeloid and plasmacytoid dendritic cell (MDC and PDC) subsets were examined by flow cytometry; functional activity by mixed lymphocyte reaction (MLR) for DC allostimulation, through 4-h 51Cr-release assay for Natural Killer (NK) and lymphokine-activated-killer (LAK) cell cytotoxicity; ELISA for spontaneous/activated cytokine release by PBMC and T cells. Significant differences occurred in several parameters between pretreatment patient and control values: fewer CD8+ cells and increased apoptosis-prone CD3+/CD95+ lymphocytes, higher frequency of MDC, reduced allostimulatory activity by ex vivo-generated DC, depressed LAK activity, elevated IL-10 and IL-12p40 production; impaired IL-12p70 and IFN-gamma production by stimulated PBMC and T cells. Only IL-12p70 level was correlated with survival. One month after radical, but not palliative surgery, the percentage of T-lymphocytes coexpressing CD3/CD95 decreased significantly, the stimulatory capacity of DC increased, and LPS-induced IL-12p70 release by PBMC rose concomitantly with the anti-CD3 stimulated-IFN-gamma production by T cells. In patients with locally advanced or metastatic disease, one and/or two combined drug cycles increased percentage of CD4+ cells and LAK cell cytotoxicity and decreased PDC frequency and spontaneous/LPS-stimulated IL-10 by PBMC. Results suggest immunological changes induced by surgical resection/combined chemotherapy indicate specific precisely-timed windows of opportunity for introducing immunotherapy in pancreatic cancer, possibly improving survival in this highly lethal disease.

An integrated humoral and cellular response is elicited in pancreatic cancer by alpha-enolase, a novel pancreatic ductal adenocarcinoma-associated antigen

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with a very poor 5-year survival rate. alpha-Enolase is a glycolytic enzyme that also acts as a surface plasminogen receptor. We find that it is overexpressed in PDAC and present on the cell surface of PDAC cell lines. The clinical correlation of its expression with tumor status has been reported for lung and hepatocellular carcinoma. We have previously demonstrated that sera from PDAC patients contain IgG autoantibodies to alpha-enolase. The present work was intended to assess the ability of alpha-enolase to induce antigen-specific T cell responses. We show that alpha-enolase-pulsed dendritic cells (DC) specifically stimulate healthy autologous T cells to proliferate, secrete IFN-gamma and lyse PDAC cells but not normal cells. In vivo, alpha-enolase-specific T cells inhibited the growth of PDAC cells in immunodeficient mice. In 8 out of 12 PDAC patients with circulating IgG to alpha-enolase, the existence of alpha-enolase-specific T cells was also demonstrated. Taken as a whole, these results indicate that alpha-enolase elicits a PDAC-specific, integrated humoral and cellular response. It is thus a promising and clinically relevant molecular target candidate for immunotherapeutic approaches as new adjuvants to conventional treatments in pancreatic cancer.

Autoantibody signature in human ductal pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy characterized by rapid progression, invasiveness, and resistance to treatment. It is the fourth leading cause of cancer death with a 2% 5-year survival rate. Biomarkers for its early detection are lacking. This study was designed to use a proteomics-based approach as a means of identifying antigens that elicit a humoral response in PDAC patients. Antibodies against PDAC-associated antigens are useful for early cancer diagnosis and therapy. Proteins from PDAC cell lines were separated by 2-DE, and the serum IgG reactivity of 70 PDAC patients, 40 healthy subjects (HS), 30 non-PDAC tumor patients, and 15 chronic pancreatitis (CP) patients was tested by Western blot analysis. Spots specifically recognized by PDAC sera and revealed by mass spectrometry corresponded to metabolic enzymes or cytoskeletal proteins. Most were up-regulated in PDAC tissues. Thus, it seems that metabolic enzymes and cytoskeletal proteins are specific targets of the humoral response during PDAC. The results of further studies of these serological-defined antigens could be of diagnostic and therapeutic significance in PDAC.

Alpha-enolase elicits specific pancreatic adenocarcinoma specific-T cell responses in healthy donors and in tumor patients (48.4)

We have demonstrated that sera from pancreatic ductal adenocarcinoma (PDAC) patients contain IgG autoantibodies to α-enolase, a glycolytic enzyme that also works as surface plasminogen receptor. As this implies that α-enolase elicits a B-cell dependent humoral response in vivo in PDAC patients, its ability to induce a T cell mediated response to PDAC was investigated. Here we show that α-enolase-pulsed dendritic cells were capable to specifically stimulate healthy autologous T cells to proliferate, secrete IFN-γ and lyse PDAC cells. In vivo, α-enolase-specific T cells completely inhibited the growth of PDAC cells in immunodeficient mice. In PDAC patients, and in particular in those with circulating IgG autoantibodies to α-enolase, the existence of memory T cells to α-enolase was also demonstrated. As a whole, these results indicate that α-enolase elicits a PDAC-specific humoral and cellular responses. The sum of its features makes α-enolase a promising candidate for new immunotherapeutic strategies in the cure of PDAC that lacks until now of efficacious therapies to associate the conventional ones.

Nonmyeloablative allogeneic blood stem cell transplantation in patients with metastatic solid tumors

BACKGROUND

The aim of the study was to evaluate the feasibility and efficacy of a non-myeloablative regimen to achieve complete donor chimerism after stem cell transplantation (SCT) in patients with metastatic solid tumors.

PATIENTS AND METHODS

Seven patients with renal cell carcinoma (RCC), 3 with colorectal carcinoma and 1 with soft tissue sarcoma received an allogeneic SCT after fludarabine (90 mg/m2) and TBI 200 cGy.

RESULTS

At day 30, median donor chimerism was 94%. Regression of tumor metastases has been observed in 1 patient with RCC. Overall, 8 patients (73%) died from progressive disease (median progression-free survival 3.7 months) and 1 (9%) from treatment-related complications; 2 patients were alive 152 and 862 days after transplantation.

CONCLUSIONS

Our preliminary results suggest that non-myeloablative SCT for metastatic solid tumors is feasible, although may lead to durable responses in a minority of patients. Careful patient selection seems to be mandatory in this transplant setting.

Antagonistic interactions between gemcitabine and 5-fluorouracil in the human pancreatic carcinoma cell line capan-2

Although the recently-developed Gemcitabine (GEM) has renewed interest in clinical research in pancreatic carcinoma, it offers modest improvement of tumor-related symptoms and marginal survival advantage, even when combined with other currently-available chemotherapeutic agents such as 5-Fluorouracil (5-FU). We hypothesized that this disappointing result could be due to an interaction between the two drugs affecting cytotoxic activity. We measured in-vitro growth inhibition, cell cycle distribution, gene and protein expression of apoptosis regulators bcl-2, bcl-x and survivin, NFkappaB and telomerase activities of human pancreatic carcinoma cell line Capan-2 following exposure to GEM and 5-FU singly or combined, by MTT assay and median effect analysis, flow cytometry, real-time RT-PCR, Western blotting, electrophoretic mobility shift assay (EMSA) and telomeric repeat amplification protocol (TRAP) assay, respectively. We found cell growth to be inhibited by both drugs, decreasing the percentage of cells in S and G2/M phases and inducing apoptosis, dependent on the levels of bcl-2, bcl-xL and survivin expression in the case of 5-FU, but not for GEM. Moreover, while telomerase activity was reduced equally by both drugs, 5-FU but not GEM effectively downregulated NFkappaB binding activity. Intriguingly, a substantial antagonistic effect was noticed when GEM was combined with 5-FU in the concentration range tested, with the exception of the TRAP assay. These indications of an antagonistic interaction between GEM and 5-FU in some pancreatic cancer context urge further investigation of both genetic and non-genetic differences to identify the variables most relevant for optimal selection and dosing of treatment for the individual patient.

Cooperative induction of a tolerogenic dendritic cell phenotype by cytokines secreted by pancreatic carcinoma cells

Ag presentation by dendritic cells (DC) is essential to effective antitumor T cell responses in cancer patients. Depending on their origin, maturation state, and the ambient cytokine milieu, DC can differentiate into distinct subpopulations, which preferentially either induce Th1 cell activation (CD11c+,CD123- myeloid DC (MDC)) or immunosuppressive T cell development (CD11c-,CD123+ plasmacytoid DC (PDC)). The present study was undertaken to characterize the effects of pancreatic carcinoma cell-derived cytokines on immature monocyte-derived DC (iMo-DC) in vitro and in vivo. Medium conditioned by human pancreatic carcinoma cells inhibited iMo-DC proliferation, expression of costimulatory molecules (CD80 and CD40) and of HLA-DR, and functional activity as assessed by MLR and IL-12p70 production. iMo-DC generated from pancreatic carcinoma patients in advanced stages of the disease similarly showed decreased levels of HLA-DR expression and reduced ability to stimulate MLR in response to CD40L and IFN-gamma. Moreover, in tumor-patient peripheral blood, the ratio of MDC to PDC cells was lower than in healthy controls due to reduced numbers of MDC CD11c+ cells. Importantly, rather than a single cytokine, a combination of tumor-derived cytokines was responsible for these effects; these were primarily TGF-beta, IL-10, and IL-6, but not vascular endothelial growth factor. In summary, we have identified an array of pancreatic carcinoma-derived cytokines that cooperatively affect iMo-DC activation in a manner consistent with ineffective antitumor immune responses.

Circulating vascular endothelial growth factor and interferon-gamma-inducible protein-10 levels in pancreatic cancer during chemotherapy

BACKGROUND

Chemotherapeutic anticancer properties are thought to derive from apoptosis pathway activation and/or cell division arrest, but animal models have also evidenced anti-angiogenic activity in some agents.

PATIENTS AND METHODS

The impact of gemcitabine, irinotecan and oxaliplatin + 5-FU upon the serum markers vascular endothelial growth factor (VEGF) (pro-angiogenic) and IFN-gamma-inducible protein (IP)-10 (anti-angiogenic) was evaluated by ELISA in locally advanced and/or metastatic cancer versus clinical efficacy and survival.

RESULTS

Patients had higher serum levels of both markers versus controls. No objective response to therapy was observed and no significant difference in either marker occurred during the first month of chemotherapy; analysis by survival showed slight transient VEGF decrease in longer survivors on day 14 and slight increase on day 28 in shorter survivors, who had baseline median IP-10 levels above longer survivors, diverging on day 14 (decrease and increase, respectively). Both groups were below baseline at day 28. Changes in IP-10 were not significant.

CONCLUSION

These preliminary results provide a rationale for exploring whether continuous or frequent administration of some anti-neoplastic agents may elicit a global anti-angiogenic activity, and whether different administration schedules of the same drug could have a synergistic or an antagonistic effect, which obviously would need to be taken into account in determining combinations with new agents targeting angiogenesis.

Human pancreatic carcinoma cells secrete bioactive interleukin-18 after treatment with 5-fluorouracil: implications for anti-tumor immune response

Recently we observed that pancreatic carcinoma cell lines constitutively express Interleukin-18 (IL-18). Bioactive IL-18 induces Interferon (IFN)-gamma production, Fas Ligand (FasL) expression, and inhibits angiogenesis, raising the issue of anti-tumor effects of a tumor-derived cytokine and motivating a more detailed analysis of IL-18 production in pancreatic carcinoma cells. This analysis included the study of effects of chemotherapeutic drugs (5-fluorouracil [5-FU], gemcitabine, cisplatin) commonly used in the treatment of pancreatic cancer patients on IL-18 production and processing. IL-18 expression and post-translational processing were determined using RT-PCR, immunoblot and ELISA in pancreatic carcinoma cell lines and in tumor tissue and serum samples from pancreatic carcinoma patients in the presence and absence of chemotherapeutic drugs. We describe expression of IL-18 in pancreatic carcinoma cells and tissues associated with significantly elevated IL-18 levels in patients sera. Specifically, Capan-2 pancreatic tumor cells produced and secreted precursor IL-18 with no apparent biological activity. However, the chemotherapeutic agent 5-FU, by inducing Caspase-1 and Caspase-3 activation, induced secretion of proteolytically processed mature and degraded IL-18 species, respectively, in Capan-2 cells. Conditioned medium from 5-FU-treated but not control Capan-2 cells induced IFN-gamma production by activated T cells in an IL-18-dependent manner. Furthermore, adjuvant polychemotherapy including 5-FU significantly increased serum levels of mature, bioactive IL-18 in pancreatic carcinoma patients. Treatment of pancreatic cancer cells with 5-FU induced Caspase-dependent processing of pro-IL18 leading to the secretion of biologically active IL-18. These findings delineate a novel mechanism by which chemotherapeutic agents may modulate local anti-tumor cell-mediated immune responses.

Phase II study of cisplatin, gemcitabine and 5-fluorouracil in advanced pancreatic cancer

BACKGROUND

The aim of this study was to determine the activity of the combination of cisplatin, gemcitabine and 5-fluorouracil (5-FU) as therapy for metastatic or locally advanced inoperable pancreatic adenocarcinoma.

PATIENTS AND METHODS

Patients with histologically proven advanced or metastatic pancreatic adenocarcinoma received first-line chemotherapy comprising cisplatin (20 mg/m2 on days 1, 8, 15, 22, 29 and 36), gemcitabine (1000 mg/m2 on days 1, 8, 29 and 36) and 5-FU (200 mg/m2 as continuous infusion on days 1-42) every 56 days.

RESULTS

A total of 34 patients were studied. Eighty courses were administered (median two courses per patient). Among 32 patients evaluable for response, two patients had a complete response and four a partial response for an overall response rate of 19% (95% confidence interval 7% to 36%). Thirteen patients had stable disease (40%) and 13 progressed. Median progression-free survival was 4.7 months, median survival 9.0 months and 26% of patients achieved 1-year survival. Ten of 25 patients (40%) with pain at presentation had a sustained reduction of analgesic consumption. The principal grade 3/4 toxicities were neutropenia, thrombocytopenia, anaemia and mucositis, occurring in 24%, 21%, 9% and 3% of patients.

CONCLUSION

This schedule seems well tolerated and active in pancreatic cancer and worthwhile of further evaluation.

PCR-detectable nonneoplastic Bcl-2/IgH rearrangements are common in normal subjects and cancer patients at diagnosis but rare in subjects treated with chemotherapy

PURPOSE

To assess whether nonneoplastic Bcl-2/IgH rearrangements act as a confounding factor in the setting of minimal residual disease analysis by evaluating their incidence in a panel of lymphoma-free subjects, including cancer-free donors and chemotherapy-naive and chemotherapy-treated cancer patients.

PATIENTS AND METHODS

A total of 501 nonlymphoma subjects have been assessed: 258 cancer-free patients and 243 patients with malignancies other than lymphoma, 112 of whom were chemotherapy-naive. Patients were primarily assessed by nested polymerase chain reaction (PCR), followed by real-time quantitative PCR if they scored positive. In addition, six initially PCR-positive cancer-free donors were prospectively reassessed by qualitative and quantitative PCR after 30 and 60 days.

RESULTS

The overall incidence of Bcl-2/IgH positivity was 9.6%, with a median number of 11 rearrangements per 1,000,000 diploid genomes (range, 0 to 2,845 rearrangements), as assessed by real-time PCR. The incidence was similar in healthy subjects and cancer patients at diagnosis (12% and 12.5%; P = not significant). In contrast, the incidence of this translocation was only 2.3% in chemotherapy-treated patients (P <.001). In addition, three initially PCR-positive cancer-free donors showed persistence of their rearrangements when assessed after 30 and 60 days.

CONCLUSION

The low incidence of nonneoplastic Bcl-2/IgH rearrangements following chemotherapy provides further evidence of the prognostic role of persistent PCR-positivity in the posttreatment molecular follow-up of follicular lymphoma patients.

G-CSF administration following peripheral blood progenitor cell (PBPC) autograft in lymphoid malignancies: evidence for clinical benefits and reduction of treatment costs

Clinical value and costs of G-CSF administration following autograft with mobilized peripheral blood progenitor cells (PBPC) were evaluated in two sequential groups of 20 patients each, treated for lymphoid neoplasms in the period February 1993 to January 1996. One group was given G-CSF (Filgrastim) (5 microg/kg/day), starting on day +1 until ANC was > 500/microl, the other received no G-CSF. All patients were conditioned with mitoxantrone 60 mg/m2 + L-PAM 180 mg/m2 and received large numbers of PBPC (median of 12 and 13 x 10(6) CD34+/kg, respectively). The median time to ANC > 500/microl was 10 days in the G-CSF group vs 14 days in controls (P < 0.0001). G-CSF was associated with a slightly faster platelet recovery (11 vs 13 days to plts > 20000/microl, P = 0.09). Median duration of fever (2.5 vs 5 days, P = 0.028), nonprophylactic antibiotics (8 vs 11 days, P = 0.019), and post-transplant hospitalization (13 vs 16 days, P = 0.0028) were also significantly reduced. The average cost per treatment in the G-CSF group amounted to about US$18241 as compared to US$21868 in the control group, implying a cost reduction of approximately 16%. Thus, G-CSF reduced morbidity with cost containment, supporting its use even if autograft is performed with large quantities of PBPC.

High prevalence of autoimmune phenomena in hepatitis C virus antibody positive patients with lymphoproliferative and connective tissue disorders

The aim of this study was to investigate whether hepatitis C virus (HCV) may perturb the immune system towards autoreactivity. We studied the relationship between the prevalence of anti-HCV and the presence of laboratory and/or clinical autoimmune features in 300 patients: lymphoid malignancies (167) and autoimmune disorders (connective tissue diseases 100; idiopathic thrombocytopenic purpura (ITP) 33). As a control, hepatitis B surface antigen (HBV) and anti-hepatitis B core antigen (anti-HBc) were related to the same parameters. Anti-HCV and anti-HBV were detected in 68/300 (22.6%) and 70/300 (24.6%) patients, respectively. HCV prevalence was 18% in lymphoproliferative disorders (anti-HBc 28.1%) and 26% in connective tissue disease (anti-HBc 16.3%). Among ITP cases, 12/33 (36.4%) were anti-HCV+ and 10/33 (30.3%) anti-HBc+. In 24/30 (80%) anti-HCV+ patients with lymphoproliferative disorders at least one serologic or clinical autoimmune abnormality was detected. To the contrary, only 10/45 (22.2%) anti-HBc+ patients with lymphoproliferative disorders had at least one serologic or clinical abnormality (P < 0.0001). A statistically significant correlation was observed between HCV prevalence and the number of autoimmune alterations in both lymphoproliferative and connective tissue disorders, which was not found for anti-HBc. These data suggest that HCV may skew the immune system toward the production of autoantibodies and also support the possibility that some cases of ITP may be linked to both HCV and HBV infection.

Probability of cure in elderly Hodgkin's disease patients

BACKGROUND

Elderly Hodgkin's disease patients have a poor prognosis. The question arises whether these patients need aggressive treatment or a palliative strategy. So far, as a consequence of the scarcity of trials designed for them, useful information can be obtained only by retrospective analyses.

METHODS

We retrospectively studied clinical data from 567 patients recorded from 1982 to 1989 in the Piemonte Hodgkin's Disease Register (PHDR). The 65 patients over 65 years of age were compared to younger ones. We analyzed the role of disease independently of confounding variables, mainly inadequacy of staging and/or treatment, comorbidity and toxicity.

RESULTS

In the elderly comorbidity was as high as 35%. Forty elderly patients (60%) entered a suboptimal plan with a low degree of aggressivity, which was different from the usual PHDR protocol. Elderly patients also had a high proportion of subsequent protocol interruptions (25%). Chemotherapy dose intensity was negatively affected by advanced age (p < 0.01 after both 3 and 6 courses of chemotherapy). Toxic deaths were significantly higher in elderly patients than in younger ones (14% vs 1%; p < 0.05). CR rates, overall survival (OS), disease-specific survival (DSS) and event free survival (EFS) were all significantly influenced by age (p < 0.01). Relapse-free survival (RFS) in patients achieving CR did not differ according to age class (77% vs 60%; p = ns). RFS was better in elderly patients entering the PHDR protocols than in those following an alternative plan (75% vs 54%; p = 0.04); however, elderly patients treated according to PHDR guidelines showed a higher incidence of toxic deaths than those treated less aggressively (23% vs 8%). The two groups had similar EFS (36% vs 24%; p = ns).

CONCLUSIONS

Elderly patients who achieve CR can have good RFS and cure is possible, but the toxic cost of conventional strategies is unacceptable and selected strategies still must be found.

High-dose sequential (HDS) chemotherapy with blood and marrow cell autograft as salvage treatment in very poor prognosis, relapsed non-Hodgkin's lymphoma

We tested the feasibility and efficacy of a novel high-dose sequential chemoradiotherapy programme (HDS) in 14 relapsed or refractory non-Hodgkin's lymphoma patients with very poor prognostic features, i.e. transformed histology, marrow invasion, low performance status. This regimen included the sequential administration of high-dose cyclophosphamide (CY) 7 g/m2 followed by high-dose methotrexate (MTX) 8 g/m2 and high-dose VP16 2 g/m2 and finally by total body irradiation (TBI)-melphalan and autograft of bone marrow and peripheral blood progenitor cells. No hemopoietic growth factor support was employed in any phase. There was one treatment-related death during the high-dose phase; three other patients did not complete the programme. All 10 patients concluding the programme achieved complete remission, with four patients in complete clinical remission at a median follow up of 34 months. Median overall survival was 27 months and median failure-free survival (FFS) was 12 months. Twenty-six well comparable patients received conventional salvage therapy during the same period. Their projected median overall survival (8 months) and median FFS (4 months) were shorter than in the HDS group (p = 0.06 for overall survival and p = 0.03 for FFS). Thus, HDS is a feasible programme and may offer superior results than conventional therapy in poor-prognosis NHL patients.

Thrombocytopenia in acute leukaemia patients treated with IL2: cytolytic effect of LAK cells on megakaryocytic progenitors

In vivo administration of recombinant interleukin 2 (IL2) has been associated, in acute leukaemia as well as in other tumours, with a variable degree of thrombocytopenia. In two patients with acute myeloid leukaemia who showed a progressive and severe fall in platelet count during daily continuous i.v. infusion of IL2, we assessed whether peripheral blood IL2-generated lymphokine activated killer (LAK) lymphocytes could affect growth of the autologous bone marrow megakaryocytic progenitor cell compartment (CFU-MK) in vitro. Following overnight pre-incubation in liquid culture of the marrow cells with autologous LAK effectors, there was an almost complete abrogation of the CFU-MK colony growth (97% and 89% inhibition). Pre-incubation in the presence of a monoclonal antibody to tumour necrosis factor alpha (TNF) completely reversed the inhibitory effect. The role played by TNF was confirmed by the finding that recombinant TNF caused a dose-dependent inhibition of the growth of CFU-MK. IL2 alone was ineffective. These results suggest that the often severe thrombocytopenia observed in patients with acute leukaemia treated with IL2 is at least partly due to autologous LAK cells activated in vivo following the administration of IL2.

Treatment of acute myeloid leukaemia patients with recombinant interleukin 2: a pilot study

Twelve patients with acute myeloid leukaemia (AML) with evidence of resistant disease were treated with recombinant interleukin 2 (rIL2) given intravenously by continuous infusion. No objective response to rIL2 alone was documented in the seven patients with advanced disease (20-90% resistant blasts in the marrow), except for a partial response to rIL2 plus chemotherapy in one. Of the five patients with limited disease (8-15% marrow blasts), three obtained a complete disappearance of the blasts following two to four 5d courses of rIL2 alone. One patient persists in fourth complete remission (CR) 30 months later, another obtained a third CR for 4 months, and the last remained in third CR for 9 months before relapsing. This latter patient achieved a fourth CR with low-dose cytarabine. The remissions have been maintained with low-dose monthly courses of rIL2 given on an out-patient basis. Two AML did not respond to rIL2 alone; one, however, obtained a fourth CR with chemotherapy and rIL2. Administration of rIL2 was accompanied by organomegaly and leucocytosis, with a frequent lymphocytosis and increase in eosinophils and large granular lymphocytes, both in the blood and in the marrow. Side effects, though often severe, were controllable using a daily dose escalating protocol and never required intensive care treatment. The results of this pilot study indicate that treatment of AML patients with rIL2 is feasible and may result in the disappearance of chemotherapy-resistant blasts in patients with limited but detectable disease. Further controlled trials in AML in CR appear warranted.

Rearrangement of the c-myc oncogene with heavy-chain immunoglobulin enhancer in tumor DNA from an acute lymphoblastic leukemia patient

The DNA obtained from the leukemia cells of an acute lymphoblastic leukemia (ALL, L3 type) with a pre-B-phenotype and a typical t(8;14) chromosomal translocation showed a rearrangement juxtaposing the c-myc gene and the immunoglobulin (Ig) heavy-chain gene enhancer. This abnormality was only present in the leukemia cells of the patient and correlated with the clinical course of the disease. The breakpoint on chromosome 8 occurred within c-myc intron 1, between 790 and 638 base pairs upstream of c-myc exon 2. This breakpoint position was the nearest to the c-myc exon 2 so far described in Burkitt's type lymphoma-leukemias, and it mapped very near to the location of a major cryptic promoter used by truncated c-myc genes. In spite of what was detected in a human lymphoma cell line (Manca) carrying a similar rearrangement, in this case the amount of c-myc transcript was not increased compared to an Epstein-Barr virus-transformed normal lymphoblastoid cell line obtained from the same patient. This may in part be due to the breakpoint position and to the fact that the efficiency of the major cryptic promoter present within the first intron could have been affected by the translocation event. Finally, as previously suggested by others, the phenotype expressed by the leukemia cells supported the notion that this particular type of rearrangement (linking together the c-myc gene and the Ig heavy-chain gene enhancer element) may be associated with a subgroup of B-ALLs showing an immunologic phenotype relatively more immature than that of classical B-ALL.

Differences in the in vitro growth pattern of fresh and cryopreserved granulo-monopoietic precursors

A study of the in vitro growth model of human granulo-monopoietic precursors (CFU-GM) before and after cryopreservation using both leukocyte feeder layers and GCT conditioned medium as the source of colony stimulating activity (CSA) is reported. The number of colonies produced with fresh cells was linearly related to the amount of marrow seeded with both CSA sources, whereas after cryopreservation this was true with feeder layers, and with GCT only at relatively high cell concentrations. This might indicate the production of granulopoietic stimulators on the part of a second population that is at least partly resistant to freezing. It seems more likely, however, that these results depend mainly on a sublethal damage to CFU-GM induced by freezing, thus making the cells hyporesponsive to some forms of CSA, such as those contained in GCT conditioned medium.

Immune-complexes (IC) in idiopathic neutropenia

The presence of immune-complexes (IC) and antipolymorphonuclear neutrophil (PMN) autoantibodies was investigated in 28 patients with chronic idiopathic neutropenia and normal or hypercellular bone marrow, 19 with a metamyelocyte arrest and 9 with more dysplastic features. The in vivo interaction between IC and PMN membrane receptors was evaluated by means of the PMN immunohistological technique. Circulating IC was evaluated with the C1q and rheumatoid factor agglutination inhibition techniques. An anti-PM autoantibody activity was investigated by challenging Fab obtained from the sera of 22 patients with PMN from normal donors. IC were detected in a high percentage of patients; in no case could an anti-PM autoantibody activity be seen. Most patients with a metamyelocyte arrest, but only 1 with more dysplastic features, were IC+. During a follow-up period of l2-52 months, none of the patients with a metamyelocyte arrest (IC+) developed anaemia, thrombocytopenia or leukaemia, while anaemia and thrombocytopenia were almost the rule in the clinical course of dysplastic bone marrow IC- patients: 2 of them developed acute myeloblastic leukaemia.

Idiopathic myelofibrosis: a possible role for immune-complexes in the pathogenesis of bone marrow fibrosis

Sixteen patients with idiopathic myelofibrosis (IM) have been investigated with respect to the possibility that immune mechanisms may be of importance in the pathogenesis of bone marrow fibrosis. The following points appear relevant: (1) immune-complexes (IC) are detectable with different techniques in a high percentage of patients with IM. Their presence is associated with evidence of bone-marrow histological markers of immune activity. (2) IgG is the main Ig class in the composition of IM IC. The results obtained favour the hypothesis that autoimmune mechanisms are involved in IM patients.

Immune complexes in aplastic anaemia

Immune complexes (IC) have been detected in nine out of 15 patients presenting with idiopathic aplastic anaemia using the polymorphonuclear neutrophil immunohistochemical technique. Immunosuppressive treatment undertaken in one patient produced a gradual recovery, the bone marrow repopulation being paralleled by the disappearance of IC. The significance of IC in aplastic anaemia and the relationship with possible pathogenesis and therapy of the disease are discussed.