Effects of tumor-promoting agents 12-O-tetradecanoylphorbol-13-acetate and phenobarbital on DNA synthesis of rat hepatocytes in primary culture

Both 12-O-tetradecanoylphorbol-13-acetate (TPA) and phenobarbital (PB) enhanced hepatocyte DNA synthesis stimulated with epidermal growth factor (EGF) by 60 to 80% in primary culture when measured by the incorporation of [3H]thymidine. This apparent increase was not due to changes in the specific activity of the deoxythymidine triphosphate (dTTP) pool. TPA enhanced DNA synthesis even at relatively high cell densities, but this was not found with the PB treatment. Although both TPA and PB enhanced DNA synthesis significantly, TPA was most effective when added during the late G1 and/or S phase of the hepatocyte cell cycle, whereas PB treatment was least effective in this period. The binding of EGF was transiently down-regulated by TPA, then restored to control values 6 h later, whereas the binding of this factor was significantly increased at both the 12th and 24th h after PB addition. These results suggest that EGF binding to hepatocytes is not correlated with the enhancement of DNA synthesis by TPA or PB and that the down-regulation of EGF binding is not causally related to the enhancement of DNA synthesis by TPA.     

Expression of c-myc in altered hepatic foci induced in rats by various single doses of diethylnitrosamine and promotion by 0.05% phenobarbital

Among the proto-oncogenes examined by northern blot analysis, c-myc, c-Ha-ras, c-fos, and c-raf-1 have been reported to be activated in rat liver cell carcinomas. However, there are relatively few reports on proto-oncogene expression in altered hepatic foci (a) early during hepatocarcinogenesis in the rat. In this study, diethylnitrosamine (a) at doses ranging from 10 to 200 mg/kg was used to initiate and phenobarbital (0.05%) to promote AHF in rats. AHF were detected by the presence of the marker enzymes glutathione s-transferase, placental form (GST-P); γ-glutamyltranspeptidase (a); glucose-6-phosphatase (G6Pase); and canalicular ad-enosine triphosphatase (a). Proto-oncogene expression in individual AHF was investigated by in situ hybridization (a). ISH for the mRNAs of c-Ha-ras, c-fos, and c-raf-1 revealed little or no expression in AHF. However, the levels of c-myc mRNA were increased in about 10% of the AHF initiated by the highest dose of DEN (200 mg/kg). Thus, altered expression of proto-oncogenes was not seen in AHF initiated by nonnecrogenic doses of DEN and promoted by phenobarbital. However, at the necrogenic dose of 200 mg/kg DEN, c-myc expression was found mostly in AHF in which abnormal expression of GST-P, GGT, G6Pase, and ATPase was also present, indicating that c-myc expression is correlated with phenotypically greater complexity of the AHF, a characteristic of malignant hepatic neoplasms in the rat. © 1995 Wiley- Liss, Inc.     

Comparison of hepatocyte phenotypes at the glutathione transferase and albumin loci in Sprague-Dawley and Nagase analbuminemic rats and F1 progeny after initiation and promotion

Hepatocarcinogenesis was examined in an initiation-promotionprotocol with a single initiating dose of 7,12-dimethylbenz[a]anthracene(DMBA) followed by promotion with phenobarbital (PB) in theNagase analbuminemic rat (NA), the Sprague-Dawley rat (SD) andtheir F1 crosses. All rats received a 70% partial hepatectomy,followed at 24 h by 30 mg DMBA/kg body wt or the solvent. Aftera 2 week recovery following surgery, half of the solvent controland initiated groups received either basal diet or promotionwith 0.05% PB mixed into the basal NIH-07 diet. After 12 weeksof promotion, the rats were killed and the livers perfused andfixed in situ with paraformaldehyde. Liver slices were paraffinembedded and stained for the placental isozyme of glutathioneS-transferase (PGST). The number of altered hepatic foci (AHF)expressing PGST per liver was determined by quantitative stereologyand used as an endpoint for comparison of initiation in therat strains. The NA rat had a lower response to this initiation–promotionprotocol than did the SD rat. The F1 progeny of the male NAand female SD rats were more similar to the NA parent in theirresponsiveness to initiation, whereas the F1 progeny of thefemale NA and male SD were similar to the SD parent in thisrespect. Putative mutagenesis and carcinogenesis were examinedin the F1 progeny of the female NA and male SD rat. In theserats, serial liver sections were stained either for albuminto detect putative mutations at that locus, or PGST to identifyputatively initiated hepatocytes. In the NA/SD F1, the numberof single hepatocytes with a putative mutation at the albuminlocus was the same (3.710⁵/liver) as those expressing a commonmarker of preneoplasia (PGST). The number of AHF expressingPGST was     

Nanoliposomal irinotecan (Nal-IRI)-based chemotherapy after irinotecan -based chemotherapy in patients with pancreas cancer

BackgroundNanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment for metastatic pancreas cancer. It is unclear, however, whether patients who had received irinotecan derive benefit.MethodsMedical records of metastatic pancreas cancer patients who had received irinotecan and then Nal-IRI were reviewed. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of >4 months defined success); adverse events and quotes from the medical record on decision-making were also recorded.ResultsSixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). The median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 4.3, 5.6 months). An exploratory comparison, based on no cancer progression with irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 5.1, 9.3 months) versus 4.3 months (95% CI: 2.3, 4.8 months); p = 0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrate several themes, including “limited treatment options,” which appeared to drive the decision to prescribe Nal-IRI.ConclusionNal-IRI might be considered in pancreas cancer patients who had received irinotecan, particularly in the absence of disease progression with the latter.     

Phase 2 study of bevacizumab plus erlotinib in patients with advanced hepatocellular cancer

BACKGROUND:

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are rational targets for therapy in hepatocellular cancer (HCC).

METHODS:

Patients with histologically proven HCC and not amenable to curative or liver directed therapy were included in this 2‐stage phase 2 trial. Eligibility included an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 and Child's Pugh score of A or B, and 1 prior systemic therapy. Patients received erlotinib 150 mg daily and bevacizumab 10 mg/kg on days 1 and 15 every 28 days. Objective tumor response was the primary end point.

RESULTS:

Twenty‐seven patients with advanced HCC (median age, 60 years) were enrolled in this multi‐institutional study. The proportion of patients with Child's A classification was 74%. One patient had a confirmed partial response and 11 (48%) achieved stable disease. Median time to disease progression was 3.0 months (95% confidence interval [CI], 1.8‐7.1). Median survival time was 9.5 months (95% CI, 7.1‐17.1). Grade 3 toxicities included rash, hypertension, fatigue, and diarrhea.

CONCLUSIONS:

In this trial, erlotinib combined with bevacizumab had minimal activity in patients with advanced HCC based on objective response and progression‐free survival. The role of targeting EGFR and VEGF in HCC needs further evaluation in molecularly selected patients. Cancer 2012. © 2011 American Cancer Society.     

Actinomycotic abscess of the anterior abdominal wall: a case report and literature review

Actinomycosis is a rare, chronic, suppurative, pseudotumoral illness caused by an anaerobic gram positive organism usually Actinomyces israelii which can mimick a tumoral pathology leading to a mutilating surgical resection. We report a case of abdominal actinomycosis and a literature review.     

A phase I and pharmacologic study of sequences of the proteasome inhibitor, bortezomib (PS-341, Velcade™), in combination with paclitaxel and carboplatin in patients with advanced malignancies

Purpose Bortezomib, a selective inhibitor of the 20S proteasome with activity in a variety of cancers, exhibits sequence-dependent synergistic cytotoxicity with taxanes and platinum agents. Two different treatment schedules of bortezomib in combination with paclitaxel and carboplatin were tested in this phase I study to evaluate the effects of scheduling on toxicities, pharmacodynamics and clinical activity.Methods Patients with advanced malignancies were alternately assigned to receive (schedule A) paclitaxel and carboplatin (IV d1) followed by bortezomib (IV d2, d5, d8) or (schedule B) bortezomib (IV d1, d4, d8) followed by paclitaxel and carboplatin (IV d2) on a 21-day cycle.Results Fifty-three patients (A 25, B 28) were treated with a median of 3 cycles (range 1–8) for schedule A and 3.5 cycles (range 1–10) for schedule B. Grade 3 or higher treatment related hematologic adverse events in all cycles of treatment included neutropenia (A 52%, B 50%), anemia (A 12%, B 7.1%) and thrombocytopenia (A 16%, B 17.9%). Non-hematologic treatment related adverse events were fairly mild (primarily grades 1 and 2). The maximum tolerated dose and the recommended doses for future phase II trials are bortezomib 1.2 mg/m², paclitaxel 135 mg/m² and carboplatin AUC = 6 for schedule A and bortezomib 1.2 mg/m², paclitaxel 175 mg/m² and carboplatin AUC = 6 for schedule B. Six (21.4%) partial responses (PR) were seen with schedule B. In contrast, only 1 (4%) PR was achieved with schedule A. Similar proteasome inhibition was achieved at MTD for both schedules.Conclusion Administration of sequential bortezomib followed by chemotherapy (schedule B) was well tolerated and associated with an encouraging number of objective responses in this small group of patients. Further studies with this administration schedule are warranted.Supported in part by grants: CA69912 and RR00585 from the National Institutes of Health.     

Hepatocellular carcinomas of the albumin SV40 T-antigen transgenic rat display fetal-like re-expression of lgf2 and deregulation of H19

Previous studies in our laboratory have shown that one of the earliest events during hepatocarcinogenesis in the albumin SV40 T antigen (Alb SV40 T Ag) transgenic rat is the duplication of chromosome 1q3.7-4.3, a region which contains the imprinted and coordinately regulated genes Igf2 and H19. We have also shown that this duplication is associated with the biallelic expression of the normally monoallelically-expressed H19. These results, however, are seemingly at odds with studies in the mouse that have shown a conservation of fetal regulatory patterns of these two genes in hepatic neoplasms. We therefore aimed in this study to determine the allelic origin of Igf2 expression in hepatocellular carcinomas of the Alb SV40 T Ag transgenic rat. Sprague-Dawley Alb SV40 T Ag transgenic rats and Brown Norway rats were reciprocally mated and the expression of Igf2 in hepatocellular carcinomas of the resulting F(1) transgene-positive female rats was analyzed by Northern blotting and RT-PCR. We determined that Igf2 was expressed exclusively from the paternal allele, which prompted the study (by the same methods) of the allelic origin of H19 in the same hepatocellular carcinomas in order to determine if the two genes remained coordinately regulated. Our results demonstrate fetal-like re-expression of Igf2 and deregulation of H19 in singular hepatocellular carcinomas of the rat. These results imply that another regulatory mechanism other than the generally accepted ICR/CTCF mechanism may play a role in the control of Igf2 and H19 expression.     

Use of KW-2189, a DNA Minor Groove-Binding Agent, in Patients with Hepatocellular Carcinoma: A North Central Cancer Treatment Group (NCCTG) Phase II Clinical Trial

Background

Hepatocellular carcinoma (HCC) is a common cancer in certain portions of the world. Currently no effective therapies exist for patients with advanced or metastatic HCC. KW-2189, a DNA minor groove-binding agent, has shown promising activity against HCC in preclinical evaluations.

Methods

A phase II study was conducted to evaluate the activity of KW-2189 in patients with histologic or cytologic confirmed advanced or metastatic HCC who had no prior systemic therapy. Patients received KW-2189 at a dose of 0.5 mg/m² administered on day 1 of a 6-week cycle. The primary endpoint of the trial was objective regression. Other endpoints included toxicity, disease-free survival, and overall survival.

Results

Due to hematologic toxicity the dose of KW-2189 was reduced to 0.375 mg/m² after 11 patients had been enrolled into the trial. Due to continued significant hematologic toxicity in the next five patients enrolled at the lower dose the trial was closed to accrual. Two responses were seen in patients enrolled at the higher dose, including one sustained CR.

Conclusion

KW-2189 showed evidence of anti-tumor activity in HCC. However, because of significant and prolonged hematologic toxicity, when given as a single dose every 6 weeks, further development of this drug in HCC is not possible. Further exploration of DNA minor groove-binding agents in the treatment of HCC appears warranted.     

A North Central Cancer Treatment Group Phase II trial of 9-aminocamptothecin in previously untreated patients with measurable metastatic colorectal carcinoma

BACKGROUND: Topoisomerase I inhibitors have demonstrated clinical activity in patients with metastatic colorectal carcinoma. The authors performed a Phase II study to evaluate the objective tumor response rate of 2 different doses and schedules of 9-aminocamptothecin (9-AC) in previously untreated patients with measurable recurrent metastatic colorectal carcinoma. METHODS: Fifty-one patients were registered. One schedule evaluated 9-AC given at 1100 microgram/m(2)/24 hours by continuous infusion for 72 hours along with granulocyte-colony stimulating factor at 5 microgram/kg/day on Days 5 through 12. Another schedule involved 9-AC at 480 microgram/m(2)/24 hours by continuous infusion for 120 hours on Days 1, 8, and 15 given every 4 weeks. RESULTS: Forty-eight of 51 patients (94%) were evaluable (28 patients who received 72-hour infusion and 20 patients who received 120-hour infusion) for response and toxicity. Significant hematologic toxicities were encountered, especially with the 72-hour infusion schedule, in which 43% (12 of 28) and 28% (8 of 28) experienced Grade 4 (National Cancer Institute Common Toxicity Criteria) leukopenia and thrombocytopenia, respectively. Grade 4 neutropenia was encountered in 61% (17 of 28) and 11% (2 of 19) of patients on the 72-hour and 120-hour infusion schedules, respectively. Diarrhea, nausea, vomiting, and hepatotoxicity were troublesome nonhematologic toxicities. Seventy-nine percent (11 of 14) and 57% (4 of 7) of the patients experiencing Grade 3 or 4 nonhematologic toxicity were on the 72-hour infusion schedule. Three patients died of chemotherapy-related toxicity. One response was observed in 48 evaluable patients (2%). CONCLUSIONS: 9-AC did not demonstrate sufficient antitumor activity and had unacceptable toxicity in previously untreated patients with metastatic colorectal carcinoma.