Phase I/II study of neoadjuvant bevacizumab, erlotinib and 5-fluorouracil with concurrent external beam radiation therapy in locally advanced rectal cancer.

BACKGROUND: To determine the maximal tolerated dose of erlotinib when added to 5-fluorouracil (5-FU) chemoradiation and bevacizumab and safety and efficacy of this combination in patients with locally advanced rectal cancer. PATIENTS AND METHODS: Patients with Magnetic resonance imaging (MRI) or ultrasound defined T3 or T4 adenocarcinoma of the rectum and without evidence of metastatic disease were enrolled. Patients received infusional 5-FU 225 mg/M2/day continuously, along with bevacizumab 5 mg/kg days 14, 1, 15 and 29. Standard radiotherapy was administered to 50.4 Gy in 28 fractions. Erlotinib started at a dose of 50 mg orally daily and advanced by 50 mg increments in the subsequent cohort. Open total mesorectal excision was carried out 6-9 weeks following the completion of chemoradiation. RESULTS: Thirty-two patients received one of three dose levels of erlotinib. Erlotinib dose level of 100 mg was determined to be the maximally tolerated dose. Thirty-one patients underwent resection of the primary tumor, one refused resection. Twenty-seven patients completed study therapy, all of whom underwent resection. At least one grade 3-4 toxicity occurred in 46.9% of patients. Grade 3-4 diarrhea occurred in 18.8%. The pathologic complete response (pCR) for all patients completing study therapy was 33%. With a median follow-up of 2.9 years, there are no documented local recurrences. Disease-free survival at 3 years is 75.5% (confidence interval: 55.1-87.6%). CONCLUSIONS: Erlotinib added to infusional 5-FU, bevacizumab and radiation in patients with locally advanced rectal cancer is relatively well tolerated and associated with an encouraging pCR.

Concurrent chemotherapy inhibits herpes simplex virus-1 replication and oncolysis.

Herpes simplex virus-1 (HSV-1) replication in cancer cells leads to their destruction (viral oncolysis) and has been under investigation as an experimental cancer therapy in clinical trials as single agents, and as combinations with chemotherapy. Cellular responses to chemotherapy modulate viral replication, but these interactions are poorly understood. To investigate the effect of chemotherapy on HSV-1 oncolysis, viral replication in cells exposed to 5-fluorouracil (5-FU), irinotecan (CPT-11), methotrexate (MTX) or a cytokine (tumor necrosis factor-α (TNF-α)) was examined. Exposure of colon and pancreatic cancer cells to 5-FU, CPT-11 or MTX in vitro significantly antagonizes both HSV-1 replication and lytic oncolysis. Nuclear factor-κB (NF-κB) activation is required for efficient viral replication, and experimental inhibition of this response with an IκBα dominant-negative repressor significantly antagonizes HSV-1 replication. Nonetheless, cells exposed to 5-FU, CPT-11, TNF-α or HSV-1 activate NF-κB. Cells exposed to MTX do not activate NF-κB, suggesting a possible role for NF-κB inhibition in the decreased viral replication observed following exposure to MTX. The role of eukaryotic initiation factor 2α (eIF-2α) dephosphorylation was examined; HSV-1-mediated eIF-2α dephosphorylation proceeds normally in HT29 cells exposed to 5-FU, CPT-11 or MTX. This report demonstrates that cellular responses to chemotherapeutic agents provide an unfavorable environment for HSV-1-mediated oncolysis, and these observations are relevant to the design of both preclinical and clinical studies of HSV-1 oncolysis.

Marizomib, a proteasome inhibitor for all seasons: preclinical profile and a framework for clinical trials.

The proteasome has emerged as an important clinically relevant target for the treatment of hematologic malignancies. Since the Food and Drug Administration approved the first-in-class proteasome inhibitor bortezomib (Velcade) for the treatment of relapsed/refractory multiple myeloma (MM) and mantle cell lymphoma, it has become clear that new inhibitors are needed that have a better therapeutic ratio, can overcome inherent and acquired bortezomib resistance and exhibit broader anti-cancer activities. Marizomib (NPI-0052; salinosporamide A) is a structurally and pharmacologically unique ß-lactone-γ-lactam proteasome inhibitor that may fulfill these unmet needs. The potent and sustained inhibition of all three proteolytic activities of the proteasome by marizomib has inspired extensive preclinical evaluation in a variety of hematologic and solid tumor models, where it is efficacious as a single agent and in combination with biologics, chemotherapeutics and targeted therapeutic agents. Specifically, marizomib has been evaluated in models for multiple myeloma, mantle cell lymphoma, Waldenstrom's macroglobulinemia, chronic and acute lymphocytic leukemia, as well as glioma, colorectal and pancreatic cancer models, and has exhibited synergistic activities in tumor models in combination with bortezomib, the immunomodulatory agent lenalidomide (Revlimid), and various histone deacetylase inhibitors. These and other studies provided the framework for ongoing clinical trials in patients with MM, lymphomas, leukemias and solid tumors, including those who have failed bortezomib treatment, as well as in patients with diagnoses where other proteasome inhibitors have not demonstrated significant efficacy. This review captures the remarkable translational studies and contributions from many collaborators that have advanced marizomib from seabed to bench to bedside.

Activation of EGFR by proteasome inhibition requires HB-EGF in pancreatic cancer cells.

Resistance to drug treatments underlies the high lethality of pancreatic ductal adenocarcinoma. Along with others, we have recently identified that proteasome inhibition is a promising therapeutic option in this highly refractory disease. The pleiotropic effects of proteasome inhibition include the activation of apoptotic signaling pathways and also antiapoptotic signaling pathways such as EGFR, AKT and the MAP kinases that reduce the apoptotic potential of this class of drug. In this study, we sought to determine the mechanism behind the activation of EGFR in response to proteasome inhibition in pancreatic cancer cells. We found that the second-generation proteasome inhibitor NPI-0052 induced the mRNA transcription of several EGFR family ligands (EGF, HB-EGF and epiregulin), however only increases in HB-EGF were detected at the protein level. Using both pharmacological inhibitors and lentiviral-mediated shRNA knockdown of EGFR ligand expression, we discovered that ligand cleavage by MMP/ADAMs and HB-EGF expression is required for activation of EGFR in response to proteasome inhibition. Furthermore, we discover that induction of HB-EGF is dependent on reactive oxygen species and p38-MAPK signaling but not ERK and that the transcription factor SP-1 is involved in NPI-0052-induced HB-EGF transcription. Together, these results indicate that stress signaling leading to induction of HB-EGF expression and increases in MMP/ADAM-dependent HB-EGF cleavage are responsible for proteasome inhibitor-induced activation of EGFR in pancreatic cancer cells.

Heparin-binding EGF-like growth factor is an early response gene to chemotherapy and contributes to chemotherapy resistance.

We have shown that one of the principle mechanisms of chemotherapy resistance involves the activation of nuclear factor kappa-B (NF-kappaB). In an effort to identify NF-kappaB-regulated chemotherapy response genes, we performed a microarray assay and observed that heparin-binding EGF-like growth factor (HB-EGF) was significantly upregulated by SN38 (a strong inducer of NF-kappaB activity) in colon cancer cells. Further studies revealed that HB-EGF was rapidly induced following a variety of chemotherapy treatments. Using RNA interference, we demonstrated that the chemotherapy-induced HB-EGF was largely dependent on activator protein-1 (AP-1) and NF-kappaB activation. Constitutive HB-EGF expression rescued AP-1/NF-kappaB small interfering RNA (siRNA) cells from chemotherapy-induced apoptosis. Meanwhile, we found that the enzymatic shedding of HB-EGF was also regulated by chemotherapy treatment, resulting in the elevated release of soluble HB-EGF from the cellular membrane. Induction of HB-EGF expression and ectodomain shedding synergistically led to robust epidermal growth factor receptor (EGFR) phosphorylation, whereas inhibition of HB-EGF expression by use of the HB-EGF inhibitor (CRM197) or siRNA resulted in the suppression of chemotherapy-induced EGFR phosphorylation. These results suggest that the chemotherapy-induced EGFR activation is regulated by HB-EGF. Finally, we demonstrated that overexpression of HB-EGF led to apoptotic resistance to chemotherapy, whereas suppression of HB-EGF expression by siRNA resulted in a dramatic increase in cell death. In summary, our study suggests that chemotherapy-induced HB-EGF activation represents a critical mechanism of inducible chemotherapy resistance. Therefore, therapeutic intervention aimed at inhibiting HB-EGF activity may be useful in cancer prevention and treatments.

Enhancement of radiosensitivity by proteasome inhibition: implications for a role of NF-kappaB.

PURPOSE: NF-kappaB is activated by tumor necrosis factor, certain chemotherapeutic agents, and ionizing radiation, leading to inhibition of apoptosis. NF-kappaB activation is regulated by phosphorylation of IkappaB inhibitor molecules that are subsequently targeted for degradation by the ubiquitin-proteasome pathway. PS-341 is a specific and selective inhibitor of the proteasome that inhibits NF-kappaB activation and enhances cytotoxic effects of chemotherapy in vitro and in vivo. The objective of this study was to determine if proteasome inhibition leads to enhanced radiation sensitivity. METHODS AND MATERIALS: Inhibition of NF-kappaB activation in colorectal cancer cells was performed by treatment of LOVO cells with PS-341 or infection with an adenovirus encoding IkappaB super-repressor, a selective NF-kappaB inhibitor. Cells were irradiated at 0, 2, 4, 6, 8, and 10 Gy with or without inhibition of NF-kappaB. NF-kappaB activation was determined by electrophoretic mobility gel shift assay, and apoptosis was evaluated using the TUNEL assay. Growth and clonogenic survival data were obtained to assess effects of treatment on radiosensitization. In vitro results were tested in vivo using a LOVO xenograft model. RESULTS: NF-kappaB activation was induced by radiation and inhibited by pretreatment with either PS-341 or IkappaBalpha super-repressor in all cell lines. Inhibition of radiation-induced NF-kappaB activation resulted in increased apoptosis and decreased cell growth and clonogenic survival. A 7-41% increase in radiosensitivity was observed for cells treated with PS-341 or IkappaBalpha. An 84% reduction in initial tumor volume was obtained in LOVO xenografts receiving radiation and PS-341. CONCLUSIONS: Inhibition of NF-kappaB activation increases radiation-induced apoptosis and enhances radiosensitivity in colorectal cancer cells in vitro and in vivo. Results are encouraging for the use of PS-341 as a radiosensitizing agent in the treatment of colorectal cancer.

Enhanced chemosensitivity to CPT-11 with proteasome inhibitor PS-341: implications for systemic nuclear factor-kappaB inhibition.

Inducible activation of nuclear factor-kappaB (NF-kappaB) inhibits the apoptotic response to chemotherapy and irradiation. Activation of NF-kappaB via phosphorylation of an inhibitor protein IkappaB leads to degradation of IkappaB through the ubiquitin-proteasome pathway. We hypothesized that inactivation of proteasome function will inhibit inducible NF-kappaB activation, thereby increasing levels of apoptosis in response to chemotherapy and enhancing antitumor effects. To assess the effects of proteasome inhibition on chemotherapy response, human colorectal cancer cells were pretreated with the dipeptide boronic acid analogue PS-341 (1 microM) prior to exposure to SN-38, the active metabolite of the topoisomerase I inhibitor, CPT-11. Inducible activation of NF-kappaB and growth response were evaluated in vitro and in vivo. Effects on p53, p21, p27 and apoptosis were determined. Pretreatment with PS-341 inhibited activation of NF-kappaB induced by SN-38 and resulted in a significantly higher level of growth inhibition (64-75%) compared with treatment with PS-341 alone (20-30%) or SN-38 alone (24-47%; P < 0.002). Combination therapy resulted in a 94% decrease in tumor size compared with the control group and significantly improved tumoricidal response to treatment compared with all treatment groups (P = 0.02). The level of apoptosis was 80-90% in the treatment group that received combination treatment compared with treatment with single agent alone (10%). Proteasome inhibition blocks chemotherapy-induced NF-kappaB activation, leading to a dramatic augmentation of chemosensitivity and enhanced apoptosis. Combining proteasome inhibition with chemotherapy has significant potential to overcome the high incidence of chemotherapy resistance. Clinical studies are currently in development to evaluate the role of proteasome inhibition as an important adjuvant to systemic chemotherapy.

Fas and Fas ligand interactions in malignant disease.

Apoptosis has been implicated in tumor development and progression. Fas (CD95) and Fas ligand (FasL) are an interacting receptor ligand pair that elicits apoptosis in many cell types. Although originally described as proteins regulating peripheral immune tolerance, accumulating evidence suggests that Fas/FasL may play an important role in carcinogenesis, tumor outgrowth, and metastasis. This review summarizes our current knowledge about the regulation of Fas and FasL expression, Fas signaling, soluble Fas production, the role(s) of Fas and FasL in hematopoietic and non-hematopoietic tumorigenesis and progression, and the potential application of Fas-induced apoptosis in cancer therapy.

Inducible chemoresistance to 7-ethyl-10-[4-(1-piperidino)-1-piperidino]-carbonyloxycamptothe cin (CPT-11) in colorectal cancer cells and a xenograft model is overcome by inhibition of nuclear factor-kappaB activation.

Limited studies have indicated that some chemotherapy agents activate the transcription factor nuclear factor-kappaB (NF-kappaB), and that this leads to suppression of the apoptotic potential of the chemotherapy. In contrast, it was reported recently that stable inhibition of NF-kappaB in four different cancer cell lines did not lead to augmentation of the chemotherapy-induced apoptosis. In this study, we have focused on colorectal cancer, which is known to be highly resistant to genotoxic chemotherapy and gamma irradiation. We show that the topoisomerase I inhibitor 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) activates NF-kappaB in most colorectal cancer cell lines. We then examine a therapeutic strategy that uses adenovirus-mediated transfer of the super-repressor IkappaBalpha to inhibit NF-kappaB activation as an adjuvant approach to promote chemosensitivity in colorectal tumor cells to treatment with CPT-11. These data demonstrate that the protection from apoptosis induced in response to CPT-11 treatment is effectively inhibited by the transient inhibition of NF-kappaB in a variety of human colon cancer cell lines and in a tumor xenograft model, resulting in a significantly enhanced tumoricidal response to CPT-11 via increased induction of apoptosis. These findings indicate that the activation of NF-kappaB by chemotherapy is an important underlying mechanism of inducible chemoresistance.

Expression of human alpha(1,3)fucosyltransferase antisense sequences inhibits selectin-mediated adhesion and liver metastasis of colon carcinoma cells.

The initial steps of leukocyte and tumor cell adhesion involve selectin receptor/ligand interactions. The selectin ligand components sialyl Lewis x and sialyl Lewis a are oncodevelopmental antigens involved in progression of adenocarcinoma. Interrupting biosynthesis of these surface glycans by inhibition of alpha(1,3)fucosyltransferase (FUT) gene expression is an attractive goal for functional and therapeutic studies. We report here the inhibition of E-selectin-mediated adenocarcinoma cell adhesion by stable transfection of antisense sequences directed at the human Lewis alpha(1,3/1,4)fucosyltransferase gene, FUT3. The metastatic parental cell line, HT-29LMM, expressed high levels of sialyl Lewis x, sialyl Lewis a, alpha(1,3/1,4)fucosyltransferase activity, and FUT3 transcript, but antisense transfectant cell lines did not. When injected into the spleens of nude mice, the stable antisense clones were unable to colonize the liver. These results provide target validation for inhibition of carcinoma metastasis with antisense FUT sequences and confirm the primacy of alpha(1,3)fucosyltransferases in the synthesis of selectin ligands.

Control of inducible chemoresistance: enhanced anti-tumor therapy through increased apoptosis by inhibition of NF-kappaB.

Programmed cell death (apoptosis) seems to be the principal mechanism whereby anti-oncogenic therapies such as chemotherapy and radiation effect their responses. Resistance to apoptosis, therefore, is probably a principal mechanism whereby tumors are able to overcome these cancer therapies. The transcription factor NF-kappaB is activated by chemotherapy and by irradiation in some cancer cell lines. Furthermore, inhibition of NF-kappaB in vitro leads to enhanced apoptosis in response to a variety of different stimuli. We show here that inhibition of NF-kappaB through the adenoviral delivery of a modified form of IkappaBalpha, the inhibitor of NF-kappaB, sensitizes chemoresistant tumors to the apoptotic potential of TNFalpha and of the chemotherapeutic compound CPT-11, resulting in tumor regression. These results demonstrate that the activation of NF-kappaB in response to chemotherapy is a principal mechanism of inducible tumor chemoresistance, and establish the inhibition of NF-kappaB as a new approach to adjuvant therapy in cancer treatment.

Cancer gene therapy.

Developments in molecular genetics, immunology, molecular and cellular biology, and tumor biology have given rise to the field of cancer gene therapy. Several gene delivery vehicles have been developed and are being examined in clinical trials. Most cancer gene therapy strategies involve introduction of genes to augment existing therapies. An overview is provided on gene delivery vehicles, gene therapy strategies, and cancer gene therapy clinical trials.

Role of splenectomy in chronic lymphocytic leukemia.

BACKGROUND: The benefit of splenectomy, performed for complications of chronic lymphocytic leukemia (CLL) including autoimmune hemolytic anemia, thrombocytopenia, hypersplenism, and symptomatic splenomegaly, has not been clearly demonstrated. The objective of this study was to determine if splenectomy achieves a predictable hematologic and survival advantage over conventional chemotherapy in patients with CLL. STUDY DESIGN: A retrospective review was performed of 77 consecutive patients with CLL who underwent splenectomy between 1970 and 1994 at the University of Texas M. D. Anderson Cancer Center. Indications for splenectomy, pre- and postoperative hematologic profiles, response to splenectomy, and time to progression and death were recorded. Kaplan-Meier life tables were constructed, and a comparison to an age- and gender-matched cohort of CLL patients treated with fludarabine and no splenectomy was performed using log rank statistical analysis. RESULTS: Seventy-six percent of the patients studied were Rai stage III/IV. Twenty of 29 patients with hemoglobin counts (Hb) < or = 10 g/dL and 11 of 18 patients with platelet counts (plt) < 50 x 10(9)/L achieved an excellent hematologic response to splenectomy. Splenectomy significantly improved survival in patients with Hb < or = 10 g/dL or plt < or = 50 x 10(9)/L (p = 0.025). Thrombocytopenia did not significantly increase postoperative morbidity, and mortality rate was not significantly different between treatment groups. CONCLUSIONS: Splenectomy significantly improves survival in selected subgroups of patients with advanced-stage CLL over that achieved with conventional chemotherapy. Based on these results, splenectomy should be performed early in the course of the disease in CLL patients with either an Hb < or = 10 g/dL or plt < or = 50 x 10(9)/L.

Survival factors in 186 patients younger than 40 years old with colorectal adenocarcinoma.

BACKGROUND: We sought to determine the clinical factors and tumor characteristics associated with the reported poor prognosis in young patients with carcinoma of the colon and rectum. STUDY DESIGN: A retrospective review was performed of 186 patients younger than 40 years of age who were treated for primary colorectal adenocarcinoma. The median age was 34.3 years, and the median follow-up period was 9.4 years. Clinical and tumor histopathologic parameters were analyzed. RESULTS: Regional lymph node metastases, distant metastases, or both, were seen at first examination in 65.6 percent of young patients. Histopathologic indicators of more aggressive tumor biology were present at a significantly higher frequency in young patients compared with patients older than 40 years (p < 0.001). Poorly differentiated tumor grade was present in 41.0 percent, signet-ring cell tumors were found in 11.1 percent, and infiltrating tumor leading edges were present in 69.0 percent of young patients. Among young patients with stage II disease, vascular invasion was a significant negative prognostic variable (p < 0.05). CONCLUSIONS: We have demonstrated an increased incidence of three biological indicators of aggressive and potentially metastatic tumor biology in 186 young patients with carcinoma of the colon and rectum: signet-ring cell carcinoma, infiltrating tumor edges, and aggressive histologic grade in the primary adenocarcinoma. The increased incidence of these three histologic measures of more aggressive carcinoma of the colon and rectum in part accounts for the higher rate of advanced disease at presentation in patients younger than 40.

High levels of gene transduction in human lung tumors following intralesional injection of recombinant adenovirus.

To effect gene transfer into large solid malignancies for the purpose of clinical application, new treatment strategies using intralesional administration of adenovirus were studied. Replication-deficient adenovirus Ad5LacZ, containing the Escherichia coli beta-galactosidase (beta-gal) gene (LacZ), was injected directly into 1-cm x 1-cm subcutaneous xenograph tumors of human large cell lung cancers (H460 and H1299). Each tumor received a single injection or three injections of purified virus, diluted in 200 microL of phosphate-buffered saline. The tumors were harvested 3 days after the last injection, serially sectioned, and stained with X-gal. The cells expressing beta-gal were counted by using digital image analysis and the percentage of tumor cells transduced was calculated. After a single viral injection of 1 x 10(9) PFU, 5 x 10(9) PFU, or 1 x 10(10) PFU solid tumor transduction increased significantly with dose escalation. At a dose of 1 x 10(10) PFU, transduction of the H1299 and H460 tumors was 80.2% and 46.7%, respectively. Dividing the viral dose into three injections given on alternating days had no significant effect on viral transduction. These data demonstrate that a large portion of an established human lung cancer cell line tumor undergoes gene transduction after a single intralesional injection of recombinant adenovirus.

Rationale for en bloc vein resection in the treatment of pancreatic adenocarcinoma adherent to the superior mesenteric-portal vein confluence. Pancreatic Tumor Study Group.

OBJECTIVE: Tumor invasion of the superior mesenteric-portal vein (SMPV) confluence is often considered a contraindication to pancreaticoduodenectomy for patients with malignant tumors of the pancreas or periampullary region. The authors sought to determine whether pancreaticoduodenectomy with en bloc resection of the SMPV confluence could be safely performed and whether tumors involving the SMPV confluence were associated with pathologic parameters suggesting poor prognosis. SUMMARY BACKGROUND DATA: Several centers have reported high rates of retroperitoneal margin positivity after pancreaticoduodenectomy for tumors of the pancreatic head and periampullary region. Positive-margin or incomplete resection is associated with early tumor recurrence and no survival benefit compared with palliative therapy. Tumor adherence to the lateral of posterior wall of the SMPV confluence often represents the only barrier to complete tumor resection at the time of pancreaticoduodenectomy. METHODS: Data on all patients undergoing pancreaticoduodenectomy for adenocarcinoma of the pancreas or periampullary region over a 3.5-year period were entered prospectively in a pancreatic tumor database. To be considered for surgery, patients were required to fulfill the following computed tomography criteria for resectability: 1) the absence of extrapancreatic disease, 2) no tumor encasement of the superior mesenteric artery or celiac axis, and 3) a patent SMPV confluence. Tumor adherence to the superior mesenteric vein or SMPV confluence was assessed intraoperatively, and en bloc venous resection was performed when necessary to achieve complete tumor extirpation. Data on operative characteristics, morbidity, mortality, tumor size, nodal metastases, margin positivity, perineural invasion, and tumor DNA content were compared for patients who did and did not receive venous resection. RESULTS: Fifty-nine patients underwent pancreaticoduodenectomy, 36 without venous resection and 23 with en bloc resection of the SMPV confluence. No differences in median hospital stay, morbidity, mortality, tumor size, margin positivity, nodal positivity, or tumor DNA content were observed between groups. CONCLUSIONS: When necessary, segmental resection of the SMPV confluence may be performed safely during pancreaticoduodenectomy for periampullary malignant tumors. Tumors invading the SMPV confluence are not associated with histologic parameters suggesting a poor prognosis. Our data suggest that venous involvement is a function of tumor location rather than an indicator of aggressive tumor biology.

Wild-type human p53 and a temperature-sensitive mutant induce Fas/APO-1 expression.

Fas/APO-1 is a cell surface protein known to trigger apoptosis upon specific antibody engagement. Because wild-type p53 can activate transcription as well as induce apoptosis, we queried whether p53 might upregulate Fas/APO-1. To explore this possibility, we examined human p53-null (H358 non-small-cell lung adenocarcinoma and K562 erythroleukemia) and wild-type p53-containing (H460 non-small-cell lung adenocarcinoma) cell lines. When H358 or H460 cells were transduced with a replication-deficient adenovirus expression construct containing the human wild-type p53 gene but not with vector alone, a marked upregulation (approximately a three-to fourfold increase) of cell surface Fas/APO-1 was observed by flow cytometry. Similarly, K562, cells stably transfected with a plasmid vector containing the temperature-sensitive human p53 mutant Ala-143 demonstrated a four- to sixfold upregulation of Fas/APO-1 by flow-cytometric analysis at the permissive temperature of 32.5 degrees C. Temperature-sensitive upregulation of Fas/APO-1 in K562 Ala-143 cells was verified by immunoprecipitation and demonstrated to result from enhanced mRNA production by nuclear run-on and Northern (RNA) analyses. Stably transfected K562 cells expressing temperature-insensitive, transcriptionally inactive p53 mutants (His-175, Trp-248, His-273, or Gly-281) failed to upregulate Fas/APO-1 at either 32.5 degrees or 37.5 degrees C. The temperature-sensitive transcription of Fas/APO-1 occurred in the presence of cycloheximide, indicating that de novo protein synthesis was not required and suggested a direct involvement of p53. Collectively, these observations argue that Fas/APO-1 is a target gene for transcriptional activation by p53.

Managing unsuspected tumor invasion of the superior mesenteric-portal venous confluence during pancreaticoduodenectomy.

Most surgeons believe that tumor invasion of the superior mesenteric-portal venous (SMPV) confluence is a contraindication to pancreaticoduodenectomy for adenocarcinoma of the pancreas or periampullary region. Traditional techniques for performing pancreaticoduodenectomy have emphasized the importance of establishing a tumor-free plane between the SMPV confluence and the neck of the pancreas. However, this maneuver does not reveal tumor invasion of the lateral wall of the superior mesenteric vein (SMV) until after gastric and pancreatic transection--a point at which the surgeon has committed to resection. This unexpected but not uncommon finding likely contributes to the high incidence of margin-positive resections and subsequent local tumor recurrence. We describe our technique for segmental resection of the SMPV confluence at the time of pancreaticoduodenectomy. Routine ligation of the splenic vein and primary anastomosis of the SMV and portal vein have been abandoned in favor of an interposition graft using internal jugular vein.

Reactivation of murine tumour-infiltrating lymphocytes with solid-phase anti-CD3 antibody: in vitro cytokine production is associated with in vivo efficacy.

Previously we described the use of solid-phase anti-CD3 monoclonal antibody (mAb) to stimulate murine tumour-infiltrating lymphocytes (TIL) and their subsequent expansion in recombinant interleukin 2 (rIL-2). In a pulmonary metastases model using the methylcholanthrene-induced sarcoma MCA-105 anti-CD3 activated TIL were capable of eradicating disease similar to TIL cultured in rIL-2 only. Here we extend these observations by characterizing the biological effects of sequential solid-phase anti-CD3 activation. TIL from MCA-105 tumour activated with solid-phase anti-CD3 on day 1 were reactivated on day 14, or day 26, or both and compared to TIL grown in rIL-2 only or TIL activated with anti-CD3 once on day 1. Reactivation enhanced in vitro proliferation 1.8- to 4-fold compared to TIL activated once with anti-CD3 (P < 0.05). In addition, the total lytic capacity of the cultures was enhanced after reactivation without changing the phenotype of the TIL cultures. Reactivation resulted in a greater in vivo efficacy when the TIL were administered within 72 h of reactivation. In contrast, TIL activated with anti-CD3 on day 1 and day 14 were least effective of all TIL cultures (P < 0.05). This correlated with in vitro cytokine production. The most effective TIL cultures in vivo produced 4- to 100-fold higher amounts of cytokines, especially interferon gamma (IFN gamma) and granulocyte macrophage colony stimulating factor (GM-CSF), than the other cultures. On the other hand, the least effective in vivo TIL culture, TIL activated with anti-CD3 on day 1 and 14, produced little or no cytokines. These data suggest that in vitro production of cytokines is indicative of in vivo efficacy of anti-CD3 activated TIL.