FDG-PET predicts treatment efficacy and surgical outcome of pre-operative chemoradiation therapy for resectable and borderline resectable pancreatic cancer.

BACKGROUND: The efficacy of neoadjuvant chemoradiotherapy (NACRT) for resectable and borderline resectable pancreatic cancer is important for predicting outcomes after radical surgery, but few clinical indicators predict outcome before resection. This study examined the utility of FDG-PET in predicting the efficacy of NACRT and outcome after radical surgery. METHODS: Eighty-three pancreatic cancer patients who underwent FDG-PET before and after NACRT and had positive standard uptake values (SUVs) before NACRT were enrolled in this study. Peri-operative clinical factors, including FDG-PET findings, were examined to predict the efficacy of NACRT and outcome after surgery. RESULTS: Evans grade I, IIA, IIB, III, and IV was determined in 11, 31, 27, 11, and 3 patients, respectively. The maximum SUVs after NACRT (post SUV-max) and tumor size were significantly decreased compared to pretreatment values (p < 0.001 and p = 0.007, respectively). The post SUV-max and regression index were significantly related to grade III/IV (p = 0.04 and p < 0.001, respectively), but only the regression index predicted NACRT efficacy (p = 0.002). The AUC of the regression index for the detection of grade III/IV was 0.822, and 13 of 14 grade III/IV patients were picked up using 50% as the threshold (p < 0.001). Patients with a regression index >50% had a significantly better prognosis after radical resection than patients with <50% (p = 0.032). Regression index as well as pathological lymph node status and resectability status were independent prognostic factors in multivariate analysis (exp 2.086, p = 0.043). CONCLUSION: The regression index is potentially a good indicator of the efficacy of NACRT and outcome after radical resection for pancreatic cancer.

Prevention of gastroduodenal content reflux and delayed gastric emptying after esophagectomy: gastric tube reconstruction with duodenal diversion plus Roux-en-Y anastomosis.

Reflux of gastroduodenal contents and delayed gastric emptying are the most common and serious problems after esophagectomy with gastric reconstruction. However, attempts to reduce the above symptoms, surgically as well as non-surgically, had no or limited effect. To address this issue, we performed retrosternal gastric reconstruction with duodenal diversion plus Roux-en-Y anastomosis (RY) in eight patients with thoracic esophageal cancer and compared the outcomes with control patients who underwent standard reconstruction. The procedure is simple, safe, and not associated with any postoperative complications. The pancreatic amylase concentrations in the gastric juice samples on postoperative day 2 were slightly lower in the non-RY group than in the RY group (1884 ± 2152 vs. 25,790 ± 23,542IU/mL, respectively, P= 0.07). Postoperative endoscopic examination showed neither reflux esophagitis nor residual gastric content in the RY group. Quality of life assessed by the Dysfunction After Upper Gastrointestinal Surgery-32 questionnaire postoperatively was significantly better in the RY group than in the non-RY group for 'decreased physical activity,''symptoms of reflux,''nausea and vomiting,' and 'pain.' The results of this pilot study suggest that gastric reconstruction with duodenal diversion plus RY seems effective in improving both the reflux and delayed gastric emptying. The benefits of this procedure need to be further assessed in a large-scale, randomized controlled trial.

The significance of abdominal para-aortic lymph node metastasis in patients with lower thoracic esophageal cancer.

Para-aortic lymph node (PALN) recurrence is often seen in patients with lower thoracic esophageal cancer treated by esophagectomy with extended lymph node dissection. However, the clinicopathological characteristics of patients with PALN metastasis and the significance of PALN dissection are unknown. A total of 283 patients with lower thoracic esophageal cancer underwent esophagectomy with lymphadenectomy at our hospital between April 1984 and March 2007. Among these 283 patients, 60 patients were enrolled in this retrospective study according to following criteria: (i) clinical T2 to T4 tumor, (ii) no clinical PALN metastasis, and (iii) received PALN dissection. PALN dissection was indicated by a tumor depth of at least T2 and no severe complications. The clinicopathological data, recurrence pattern, and overall survival were compared between patients with PALN and without PALN metastasis. The mean length of surgery was 587 min and the mean blood loss was 1383 mL. The morbidity was 33.3% and mortality was 5% in this series. Sixteen patients (26.7%) had PALN metastasis; these showed significantly more lymph node metastases (15.8 ± 13.2 vs. 3.0 ± 3.2, P < 0.0001) and significantly worse survival rates (53.3% vs. 79.9% at 1 year, 6.7% vs. 62.0% at 3 years, P < 0.0001) than patients without PALN metastasis. The incidence of lymph node recurrence (P < 0.0001) and hematogenous recurrence (P= 0.0487) was also higher in patients with PALN metastasis than in patients without PALN metastasis. Among the 16 patients with PALN metastasis, a univariate analysis revealed total number of metastatic nodes < 8 (P= 0.0325) to be a significant prognostic factor. A multivariate logistic regression analysis of the regional lymph nodes identified the invasion of the lower mediastinal nodes (hazard ratio = 6.120) and retroperitoneal nodes (hazard ratio = 15.167) to be significantly correlated with PALN metastasis. PALN metastasis is suggested to be related to the systemic spread of lymphatic metastasis even in lower thoracic esophageal cancer. PALN dissection for pathological PALN(+) patients should not be performed. It remains to be determined in future prospective studies whether patients without pathological PALN metastasis, but showing PALN micrometastasis, could achieve improved survival with PALN dissection.

Ep-CAM is a significant prognostic factor in pancreatic cancer patients by suppressing cell activity.

The identification of molecular markers useful for predicting prognosis in pancreatic cancer patients is crucial for advances in disease management. The epithelial cell adhesion molecule (Ep-CAM) is known to express in most epithelial malignancies and was reported as a tumor marker or a candidate of molecular targeting therapy. However, the clinical significance of Ep-CAM expression in pancreatic cancer is not well-known. We determined the difference of malignant potential between parental and Ep-CAM-transfected pancreatic cancer cell lines by using proliferation, invasion and migration assay. Furthermore, we determined the relationship between tumoral Ep-CAM expression of resected specimens and clinical prognosis in 95 pancreatic cancer patients receiving radical surgery at two different cancer centers. One of the three Ep-CAM-transfected cell lines showed significantly low proliferation rate compared with the parental cell, while there was no difference in the other two cell lines. In invasion and migration assays, Ep-CAM-transfected cells showed significantly lower malignant potential than parental in all of the three cell lines. In 95 pancreatic cancer patients, 47 patients showed high-Ep-CAM expression, while 48 patients showed low, and there was no difference of clinicopathological features between Ep-CAM high and low-expression group. High-Ep-CAM expression group showed significantly good prognosis in overall survival (3-year survival; 56.2 versus 19.2%, P=0.0018) as well as in disease-free survival (3-year survival; 40.3 versus 14.4%, P=0.038) compared with low-expression group. In addition, the impact of Ep-CAM was observed strongly in LN-negative group when the influence of Ep-CAM was examined with dividing patients into LN-positive and negative group. In multivariate analysis, Ep-CAM expression was one of the independent prognostic factors as well as histology and lymph node metastasis. Ep-CAM expression was found to be related to the suppression of pancreatic cancer cell activity and the good prognosis in pancreatic cancer patients receiving the curative resection.

Correlation between pretherapeutic d-dimer levels and response to neoadjuvant chemotherapy in patients with advanced esophageal cancer.

Neoadjuvant chemotherapy may improve survival of responders in esophageal cancer patients but is useless and harmful in non-responders. Thus, it is important to predict the effect of the chemotherapy, and that any predictor must be applicable clinically. The aim of this study is to examine the correlation between pretherapeutic hypercoagulopathy as determined by plasma d-dimer levels and response to chemotherapy. In 71 patients with esophageal cancer who underwent neoadjuvant chemotherapy (cisplatin, adriamycin and 5-fluorouracil) followed by surgery, plasma d-dimer levels were measured before chemotherapy and the clinical and pathological responses to chemotherapy were assessed at 4 weeks after therapy (after surgery). Pretherapeutic plasma d-dimer level was significantly lower in clinical responders (complete response/partial response [CR/PR]; 0.62 +/- 1.10 microg/mL, mean +/- SD) than in non-responders (no change/progressive disease [NC/PD]; 1.15 +/- 1.08 microg/mL, P = 0.0491), and in pathological responders (Grade 1b-3; 0.62 +/- 1.11 microg/mL) and non-responders (Grade 0-1a; 1.15 +/- 1.05 microg/mL, P = 0.0107). The optimal cut-off level of the plasma d-dimer levels for predicting clinical and pathological responses was 0.6 microg/mL. Then, sensitivity and specificity for the prediction of CR/PR were 68% and 73%, and those for Grade 1b-3 were 91% and 69%, respectively. Our results suggested that pretherapeutic plasma d-dimer level correlated significantly with clinical and pathological responses to chemotherapy. Pretherapeutic plasma d-dimer level can be used as a predictor for chemosensitivity.

The toxic conformation of the 42-residue amyloid beta peptide and its relevance to oxidative stress in Alzheimer's disease.

Senile plaques in the brain of patients with Alzheimer's disease mainly consist of aggregates of amyloid beta peptides (Abeta42, Abeta40). Abeta42 is more neurotoxic than Abeta40. This review describes recent findings from a structural analysis of Abeta42 aggregates and discusses their relevance to neurotoxicity through the formation of radicals.

Cellular thiol status-dependent inhibition of tumor cell growth via modulation of p27(kip1) translocation and retinoblastoma protein phosphorylation by 1'-acetoxychavicol acetate.

1'-Acetoxychavicol acetate (ACA) has been shown to inhibit tumor cell growth, but there is limited information on its effects on cell signaling and the cell cycle control pathway. In this study, we sought to determine how ACA alters cell cycle and its related control factors in its growth inhibitory effect in Ehrlich ascites tumor cells (EATC). ACA caused an accumulation of cells in the G1 phase and an inhibition of DNA synthesis, which were reversed by supplementation with N-acetylcysteine (NAC) or glutathione ethyl ester (GEE). Furthermore, ACA decreased hyperphosphorylated Rb levels and increased hypophosphorylated Rb levels. NAC and GEE also abolished the decease in Rb phosphorylation by ACA. As Rb phosphorylation is regulated by G1 cyclin dependent kinase and CDK inhibitor p27(kip1), which is an important regulator of the mammalian cell cycle, we estimated the amount of p27(kip1) levels by western blotting. Treatment with ACA had virtually no effect on the amount of p27(kip1) levels, but caused a decrease in phosphorylated p27(kip1) and an increase in unphosphorylated p27(kip1) as well as an increase in the nuclear localization of p27(kip1). These events were abolished in the presence of NAC or GEE. These results suggest that in EATC, cell growth inhibition elicited by ACA involves decreases in Rb and p27(kip1) phosphorylation and an increase in nuclear localization of p27(kip1), and these events are dependent on the cellular thiol status.

Preoperative chemotherapy for clinically node-positive patients with squamous cell carcinoma of the esophagus.

Lymph node metastasis is one of the strongest prognostic factors for patients with esophageal cancer. Whether neoadjuvant chemotherapy is effective for metastatic nodes and improves the prognosis of clinically node-positive patients is unknown. Seventy-seven patients with clinically node-positive esophageal cancer, who were given preoperative chemotherapy (5-fluorouracil, cisplatin and adriamycin) followed by surgery, were retrospectively analysed. The histological effectiveness of the chemotherapy against the main tumor in the resected specimen was correlated with nodal status and prognosis. Of the 77 patients, the histological effects in the main tumors were grade 3 in one patient (1.3%), grade 2 in 10 (13.0%), grade 1b in seven (9.1%), grade 1a in 50 (64.9%) and grade 0 in nine (11.7%). Eleven patients (14.3%) were found to be pathologically node-negative. The pathological stages were significantly earlier in responders (grades 3-1b) than in non-responders (grades 1a-0) (P = 0.0001). The responders showed a significantly lesser degree of lymph node metastasis (P = 0.0005), fewer metastatic nodes (2.2 +/- 3.1 vs. 12.0 +/- 20.5, P = 0.0482) and better survival (P = 0.002) than the non-responders. The most common failure pattern for the non-responders was lymphatic recurrence, with an incidence of 47.5% (28/59), while that for the responders was 16.7%. Responders to neoadjuvant chemotherapy show fewer metastatic nodes and better prognosis than non-responders. Neoadjuvant chemotherapy may offer clinical benefit to responders.

Prognosis of patients who develop cervical lymph node recurrence following curative resection for thoracic esophageal cancer.

Patients with esophageal cancer often display relapse at cervical nodes after surgery, but their prognosis and a suitable therapy remains unknown. We retrospectively reviewed the records for 35 patients who underwent esophagectomy with lymphadenectomy who then displayed relapse at the cervical lymph nodes alone between 1985 and 2003 in order to observe the prognostic factors for such patients. Median survival time from the date of recurrence for all 35 patients was 12 months with 1-year, 2-year, 3-year and 5-year survival rate of 47.2%, 26.5%, 17.7% and 8.8%, respectively. With regard to the initial treatment against cervical node recurrence, 15 patients were treated by radiotherapy alone, eight by chemoradiotherapy, 11 by surgery and one by chemotherapy alone. Univariate analysis revealed that cervical node dissection at the prior esophagectomy (yes/no, P = 0.0178), time to recurrence (> 9 months or < 9 months, P = 0.0497) and the number of relapsed nodes (solitary/multiple, P = 0.0029) were significant prognostic factors. Among these factors, the number of relapsed nodes (solitary/multiple) was found to be the only significant prognostic factor with an odds ratio of 2.409 and 95% confidence interval of 1.033-5.619 by multivariate analysis. In conclusion, cervical node metastasis is generally considered to be distant organ metastasis. However, if it is a solitary node recurrence, substantial survival can be attained by appropriate loco-regional therapy.

Suppressive activity of a fermented grain food product on dextran sulfate sodium-induced experimental colitis in mice.

Oxidative stress has been shown to play pivotal roles in the onset of inflammatory bowel disease. We evaluated the effects of a dietary anti-oxidant, Antioxidant Biofactor (AOB), a processed grain food, on dextran sulfate sodium (DSS)-induced colitis in mice. Female ICR mice were fed a diet containing 0.1% or 1% AOB for 2 weeks, during which they were given 5% DSS in drinking water for the latter 1 week to induce colitis. A diet containing 1% AOB, but not that with 0.1% AOB, attenuated DSS-induced body weight loss and colon shortening (each, P < 0.05), and dramatically improved colitis histologic scores. In addition, DSS-induced increases in colonic mucosal IL-1beta, but not TNF-alpha, protein levels were significantly abrogated in 1% AOB-fed mice (P < 0.05). Further, 1% dietary AOB abolished the expression of IL-1beta mRNA levels in colonic mucosa (P < 0.01). Our results suggest that AOB is effective for the prevention of DSS-induced colitis in mice.

Extract of vinegar "Kurosu" from unpolished rice inhibits the development of colonic aberrant crypt foci induced by azoxymethane.

The modifying effects of administrating an ethyl acetate extract of "Kurosu" (EK), a vinegar made from unpolished rice, on development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats. We also assessed the effects of EK on proliferating cell nuclear antigen (PCNA) index in ACF, prostaglandin (PG) E2 expression in the colonic mucosa and activities of detoxifying enzymes of glutathione S-transferase (GST) and quinone reductase (QR) in the liver. To induce ACF, rats were given two weekly subcutaneous injections of AOM (20 mg/kg body wt). They also received drinking water containing 0, 0.05, 0.1 or 0.2% EK for 4 weeks, starting 1 week before the first dosing of AOM. AOM exposure produced 140 +/- 23 ACF/rat at the end of the study (week 4). EK administration dose-dependently inhibited ACF formation and inhibition by 0.2% EK was statistically significant (P < 0.002). Treatment with EK significantly lowered PCNA index in ACF and reduced PGE2 content in the colonic mucosa, while EK elevated liver GST and QR activities. These findings suggest that EK may be effective for inhibiting colonic ACF, through induction of liver GST and QR and possibly alteration of PGE2 production.

An immunohistochemical study of cyclooxygenase (COX)-2 expression in endocrine tumors of the pancreas.

Cyclooxygenase (COX) is a key rate-limiting enzyme in prostaglandin biosynthesis. There are two isoforms of COX, referred to as COX-1 and COX-2. COX-2, an inducible form of COX, is found to be overexpressed in various neoplasms and is believed to play an important role in tumorigenesis and tumor development. In this study, we investigated expression of the COX-2 protein in human endocrine tumors of the pancreas (N=23; 6 insulinomas, one glucagnoma, 2 gastrinomas, and 14 non-functioning tumors) using immunohistochemistry. Strong COX-2 expression was confirmed in normal islet tissue as previously reported. COX-2 immunoreactivity was detected in 65% (15 out of 23) of these tumors with a moderate to strong intensity. In all nine functioning tumors, COX-2 expressions were preserved with the weak or strong intensity. In contrast, COX-2 was present in 6 out of 14 nonfunctioning tumors. The correlation between COX-2 expression and their function was significant (p<0.05). We found that expression of this enzyme was detected in 11 out of 15 benign tumors and in 4 out of 8 malignant tumors, respectively. Our results suggest that COX-2 may play an important role in the endocrine function of islet tumors. Additionally, malignancy was not related to COX-2 expression.

Brillouin scattering study of elastic properties in ferroelectric copolymer single-crystalline films.

The in-plane elastic properties of as-grown random copolymer poly (vinylidene fluoride-trifluoroethylene) single-crystalline films with 75/25 molecular ratio have been studied by Brillouin light scattering up to approximately 140 degrees C from room temperature, covering the D6h-C2v ferroelectric phase transition at approximately 126 degrees C. The in-plane longitudinal acoustic (LA) phonons propagating parallel and perpendicular to the polymer chains were examined. In spite of the strongly first-order nature of the phase transition, both LA velocities exhibit only a broad down step in the temperature range between approximately 100 degrees C and approximately 130 degrees C, depending on the propagation direction, with increasing temperature. The LA phonon width perpendicular to the polymer chains increases with increasing temperature, and exhibits a broad maximum centered at approximately 120 degrees C. On the other hand, the LA phonon width along the polymer-chain axis is much wider than the width perpendicular to the polymer chains, and continues to increase even in the paraelectric phase. Treating the E(u) symmetry electric polarizations (Px,P(y)) of the D6h point group as the macroscopic order parameter, a Laudau free energy was developed to discuss the elastic properties. Using the free energy, we found that the elastic anomalies expected through the electrostrictive couplings between the order parameter and the elastic strains are strongly suppressed by the intrinsic electrical nature of the ferroelectric polymer. For both LA phonons, the temperature development of the phonon frequency and width can be reasonably reproduced by the Cole-Davidson relaxation model for the velocity dispersion with an exponent of betaCD=0.4. The relaxation time was found to obey the Arrhenius law tau=tau(0) exp(DeltaE/k(B)T) with DeltaE=0.55+/-0.01 eV and tau(0)=(4.0+/-0.6)x10(-18) s. At 24.0 degrees C in the ferroelectric phase, the in-plane phonon width anisotropy can be reasonably described by gammaB(straight theta)/2pi=0.18+0.72 sin4 straight theta for the LA phonon and gammaB(straight theta)/2pi=0.02+0.095 sin2 2straight theta for the transverse acoustic phonon, where the phonon propagation angle straight theta is measured from the perpendicular direction with respect to the polymer-chain axis. The straight theta dependence is strongly related to the one-dimensional freedom constrained in each copolymer chain.

Chemoprevention of azoxymethane-induced rat aberrant crypt foci by dietary zerumbone isolated from Zingiber zerumbet.

The modifying effects of dietary feeding of zerumbone isolated from Zingiber zerumbet on the development of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in male F344 rats. Expression of cyclooxygenase (COX)-2 in colonic mucosa exposed to AOM and/or zerumbone was also assayed. In addition, we assessed the effects of zerumbone on cell proliferation activity of crypts by counting silver-stained nucleolar organizer regions protein (AgNORs) in colonic cryptal cell nuclei. To induce ACF rats were given three weekly subcutaneous injections of AOM (15 mg/kg body weight). They were also fed the experimental diet containing 0.01% or 0.05% zerumbone for 5 weeks, starting one week before the first dosing of AOM. AOM exposure produced 84+/-13 ACF/rat at the end of the study (week 5). Dietary administration of zerumbone caused reduction in the frequency of ACF: 72+/-17 (14% reduction) at a dose of 0.01% and 45+/-18 (46% reduction, p<0.001) at a dose of 0.05%. Feeding of zerumbone significantly reduced expression of COX-2 and prostaglandins in colonic mucosa. Zerumbone feeding significantly lowered the number of AgNORs in colonic crypt cell nuclei. These findings might suggest possible chemopreventive ability of zerumbone, through suppression of COX-2 expression, cell proliferating activity of colonic mucosa, and induction of phase II detoxification enzymes in the development of carcinogen-induced ACF.

Toxic dose of a simple phenolic antioxidant, protocatechuic acid, attenuates the glutathione level in ICR mouse liver and kidney.

It has previously been reported that a toxic dose of protocatechuic acid (PA), a naturally occurring simple phenolic antioxidant in dietary plant foodstuff, has a potential to enhance tumorigenesis and induce contact hypersensitivity in mouse skin. In this study, the modifying effect of a toxic dose of PA on the glutathione (GSH) level in mouse liver and kidney was examined. Intraperitoneal administration of PA (500 mg/kg) caused significant hepatic and nephrotic GSH depletion. Interestingly, slight but significant hepatotoxicity and nephrotoxicity, characterized by the enhancement of plasmic alanine aminotrasferase (ALT) activity and urea level, respectively, were also observed. The subchronic administration of PA (0.1% in drinking water) for 60 days showed not only a significant decrease in the GSH level in kidney but also a significant enhancement of ALT activity in plasma. The protective role of GSH for acute hepatotoxicity using GSH-depleted mice administered a GSH synthesis inhibitor buthionine sulfoximine was also demonstrated. Thus, it is suggested that overdoses of PA can disturb the detoxification of other electrophilic toxicants including ultimate carcinogens.

Diacylglycerol kinase gamma is one of the specific receptors of tumor-promoting phorbol esters.

Diacylglycerol kinase (DGK) and protein kinase C (PKC) are two different enzyme families that interact with diacylglycerol. Both enzymes contain cysteine-rich C1 domains with a zinc finger-like structure. Most of the C1 domains of PKCs show strong phorbol-12,13-dibutyrate (PDBu) binding with nanomolar dissociation constants (K(d)'s). However, there has been no experimental evidence that phorbol esters bind to the C1 domains of DGKs. We focused on DGK gamma because its C1A domain has a high degree of sequence homology to those of PKCs, and because DGK gamma translocates from the cytoplasm to the plasma membrane following 12-O-tetradecanoylphorbol-13-acetate treatment similar to PKCs. Two C1 domains of DGK gamma (DGK gamma-C1A and DGK gamma-C1B) were synthesized and tested for their PDBu binding along with whole DGK gamma (Flag-DGK gamma) expressed in COS-7 cells. DGK gamma-C1A and Flag-DGK gamma showed strong PDBu binding affinity, while DGK gamma-C1B was completely inactive. Scatchard analysis of DGK gamma-C1A and Flag-DGK gamma gave K(d)'s of 3.1 and 4.4 nM, respectively, indicating that the major PDBu binding site of DGK gamma is C1A. This is the first evidence that DGK gamma is a specific receptor of tumor-promoting phorbol esters.

Quassinoids from Eurycoma longifolia as plant growth inhibitors.

Seven quassinoids including a new 12-epi-11-dehydroklaineanone were isolated from the leaves of Eurycoma longifolia (Simaroubaceae) as plant growth inhibitors or related compounds. The strongest activity was found in 14,15beta-dihydroxyklaineanone.

Does pleural lavage cytology before thoracic closure predict both patient's prognosis and site of cancer recurrence after resection of esophageal cancer?

BACKGROUND: Operative manipulation occasionally exfoliates and spreads cancer cells in the surgical field, and it is a matter of concern whether the exfoliated cancer cells actually affect the patient's prognosis and sites of cancer recurrence. METHODS: In 240 patients with esophageal cancers, lavage cytology (LC) of the right pleural cavity was performed before and after esophageal resection combined with regional lymphadenectomy. The cytologic results were compared with the pathologic factors associated with cancer extension, postoperative survival, and cause of surgical failure. RESULTS: Only 3 patients (1.3%) were LC positive before resection. Of the 237 LC-negative patients, LC was also negative after resection in 215 patients (90.7%) (LC-/-), but LC became positive after resection in 22 patients (9.3%) (LC-/+). The 3-year survival rate was 0% in the LC-/+ group versus 65% in the LC-/- group, and the median survival rates were 10.9 months and 25.0 months, respectively (P <.0001). Multivariate analysis revealed that LC-/+ was an independent prognostic factor (P =.0331), along with nodal involvement and depth of cancer invasion. However, there were no significant differences in the sites of cancer recurrence between the 2 groups. Only 1 patient was found to develop the first recurrence in the pleural cavity. The LC-/+ group had a higher incidence of bulky lymph-node metastasis (P =.0009). CONCLUSIONS: Pleural LC after resection of esophageal cancer seems to be a prognostic indicator of overall recurrence, but not necessarily in the pleural cavity. Patients with a positive LC after resection may benefit most by effective systemic adjuvant chemotherapy.

Toward the identification of selective modulators of protein kinase C (PKC) isozymes: establishment of a binding assay for PKC isozymes using synthetic C1 peptide receptors and identification of the critical residues involved in the phorbol ester binding.

Conventional and novel protein kinase C (PKC) isozymes contain two cysteine-rich C1 domains (C1A and C1B), both of which are candidate phorbol-12,13-dibutyrate (PDBu) binding sites. We previously synthesized C1 peptides (of approximately 50 residues) corresponding to all PKC isozymes and measured their PDBu binding affinity. While many of these peptide receptors exhibited PDBu affinities comparable to the respective complete isozyme, some of the C1A peptides could not be used because they undergo temperature dependent inactivation. This problem was however eliminated by 4 degrees C incubation or elongation of the 50-mer C1 peptides at both N- and C-termini to increase their folding efficiency and stability. These findings enabled us to determine the K(d)'s of PDBu for all PKC C1 peptides (except for theta-C1A) and establish the value of these peptides as readily available, stable, and easily handled surrogates of the individual isozymes. The resultant C1 peptide receptor library can be used to screen for new ligands with PKC isozyme and importantly C1 domain selectivity. Most of the C1 peptide receptors showed strong PDBu binding affinities with K(d)'s in the nanomolar range (0.45-7.4 nM). Two peptides (delta-C1A and theta-C1A) bound PDBu over 100-fold less tightly. To identify the residues that contribute to this affinity difference, several mutants of delta-C1A and theta-C1A were synthesized. Both the G9K mutant of delta-C1A and the P9K mutant of theta-C1A showed K(d)'s of 2-3 nM. This approach provides a useful procedure to determine the role of each C1 domain of the PKC isozymes by point mutation.