Enhancement of clonogenicity of human multiple myeloma by dendritic cells.

Infiltration by dendritic cells (DCs) is a common feature of most human tumors. Prior studies evaluating the interaction of DCs with tumors have focused largely on their immunologic properties (for review see Banchereau, J., and R.M. Steinman. 1998. Nature. 392:245-252). In this study, we show that the clonogenicity of several human tumor cell lines and primary tumor cells from myeloma patients is enhanced by their interactions with DCs. Myeloma cells cultured in the presence of DCs have an altered phenotype with an increased proportion of cells lacking terminal plasma cell differentiation marker CD138. DC-tumor interaction also leads to the up-regulation of B cell lymphoma 6 expression in myeloma cells. Effects of DCs on myeloma cells are inhibited by blockade of the receptor activator of NF-kB (RANK)-RANK ligand and B cell-activating factor-APRIL (a proliferation-inducing ligand)-mediated interactions. Together, these data suggest that tumor-DC interactions may directly impact the biology of human tumors, particularly multiple myeloma, and may be a target for therapeutic intervention.

Adjuvant FOLFOX chemotherapy and splenomegaly in patients with stages II-III colorectal cancer.

BACKGROUND: The impact of adjuvant chemotherapy on hepatic function and portal hypertension in patients with stages II-III colon cancer has not been previously described. We conducted a retrospective study to assess the effects of adjuvant FOLFOX chemotherapy on the splenic index (SI) as a surrogate marker for portal hypertension. METHODS: Stage II-III colorectal cancer patients treated with adjuvant FOLFOX or fluorouracil/leucovorin (5-FU/LV) at Roswell Park Cancer Institute between 2002 and 2006 were identified. Computerizedt omography (CT) scans obtained prior to and at completion of chemotherapy, and every 6 months thereafter were reviewed. Splenic size was evaluated using the SI (SI = length x width x height of the spleen). RESULTS: 40 patients were identified in the FOLFOX group and 23 in the 5-FU/LV group. After 6 months of adjuvant chemotherapy, the mean increase in SI was 45.7 and 16.3% in the FOLFOX and 5-FU/LV groups, respectively (p = 0.0069). SI increased by >100% in 6 patients (15%) in the FOLFOX group versus none in the 5-FU/LV group (p = 0.16). The mean SI at completion of adjuvant chemotherapy was significantly higher in the FOLFOX group than in the 5-FU/LV group (p = 0.007). The mean SI decreased steadily over a period of 2 years after discontinuation of FOLFOX, suggesting potential reversibility of oxaliplatin-induced hepatic injury in this setting. CONCLUSIONS: Adjuvant FOLFOX significantly increases the SI in patients with resected colorectal cancer in comparison to adjuvant 5-FU/LV. The increase in SI may be a marker of oxaliplatin-induced hepatic injury and should be investigated further in prospective longitudinal studies of oxaliplatin-based adjuvant chemotherapy.

Bortezomib disrupts tumour-dendritic cell interactions in myeloma and lymphoma: therapeutic implications.

Recent studies have shown that the interactions between tumour and dendritic cells (DCs) promote clonogenic growth of lymphoproliferative tumours, particularly myeloma. The present study showed that the proteasome inhibitor, bortezomib, disrupts this interaction. Targeting the drug to DCs was required for optimal suppression of tumour growth, including primary myeloma tumour progenitors in clonogenic assays. Bortezomib lead to dose-dependent induction of apoptosis in both myeloid and plasmacytoid DCs, and the sensitivity of DCs to bortezomib was comparable with that of tumour cells. These data suggest that disruption of tumour-DC interactions may contribute to the clinical effects of bortezomib.