miRNA-34c-5p inhibits amphiregulin-induced ovarian cancer stemness and drug resistance via downregulation of the AREG-EGFR-ERK pathway.

Epithelial ovarian cancer is the most lethal gynecological cancer mainly due to late diagnosis, easy spreading and rapid development of chemoresistance. Cancer stem cells are considered to be one of the main mechanisms for chemoresistance, as well as metastasis and recurrent disease. To explore the stemness characteristics of ovarian cancer stem cells, we successfully enriched ovarian cancer stem-like cells from an established ovarian cancer cell line (SKOV-I6) and a fresh ovarian tumor-derived cell line (OVS1). These ovarian cancer stem-like cells possess important cancer stemness characteristics including sphere-forming and self-renewing abilities, expressing important ovarian cancer stem cell and epithelial-mesenchymal transition markers, as well as increased drug resistance and potent tumorigenicity. Microarray analysis of OVS1-derived sphere cells revealed increased expression of amphiregulin (AREG) and decreased expression of its conserved regulatory microRNA, miR-34c-5p, when compared with the OVS1 parental cells. Overexpression of AREG and decreased miR-34c-5p expression in SKOV-I6 and OVS1 sphere cells were confirmed by quantitative real-time PCR analysis. Luciferase reporter assay and mutant analysis confirmed that AREG is a direct target of miR-34c-5p. Furthermore, AREG-mediated increase of sphere formation, drug resistance toward docetaxel and carboplatin, as well as tumorigenicity of SKOV-I6 and OVS1 cells could be abrogated by miR-34c-5p. We further demonstrated that miR-34c-5p inhibited ovarian cancer stemness through downregulation of the AREG-EGFR-ERK pathway. Overexpression of AREG was found to be correlated with advanced ovarian cancer stages and poor prognosis. Taken together, our data suggest that AREG promotes ovarian cancer stemness and drug resistance via the AREG-EGFR-ERK pathway and this is inhibited by miR-34c-5p. Targeting AREG, miR-34c-5p could be a potential strategy for anti-cancer-stem cell therapy in ovarian cancer.

Role of type III secretion in Edwardsiella tarda virulence.

Edwardsiella tarda is a Gram-negative enteric bacterium affecting both animals and humans. Recently, a type III secretion system (TTSS) was found in Ed. tarda. Such systems are generally used by bacterial pathogens to deliver virulence factors into host cells to subvert normal cell functions. Genome-walking was performed from the eseB and esrB genes (homologues of Salmonella sseB and ssrB, respectively) identified in previous studies, to determine the sequences of the TTSS. Thirty-five ORFs were identified which encode the TTSS apparatus, chaperones, effectors and regulators. Mutants affected in genes representing each category were generated and found to have decreased survival and growth in fish phagocytes. LD(50) values of the mutants were increased by at least 10-fold in comparison to those of the wild-type strain. The adherence and invasion rates of the esrA and esrB mutants were enhanced while those of the other mutants remained similar to the wild-type. The eseC and eseD mutants showed slight autoaggregation in Dulbecco's Modified Eagle Medium, whereas the rest of the mutants failed to autoaggregate. Regulation of the TTSS was found to involve the two-component regulatory system esrA-esrB. This study showed that the TTSS is important for Ed. tarda pathogenesis. An understanding of this system will provide greater insight into the virulence mechanisms of this bacterial pathogen.

Regulation of a type III and a putative secretion system in Edwardsiella tarda by EsrC is under the control of a two-component system, EsrA-EsrB.

Edwardsiella tarda is a gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and gastro- and extraintestinal infections in humans. A type III secretion system (TTSS) and a putative secretion system (EVP) have been found to play important roles in E. tarda pathogenesis. Our previous studies suggested that the TTSS and EVP gene clusters were regulated by a two-component system of EsrA-EsrB. In the present study, we characterized another regulator, EsrC, which showed significant sequence similarity to the AraC family of transcriptional regulators. Mutants with in-frame deletions of esrC increased the 50% lethal doses in blue gourami fish, reduced extracellular protein production, and failed to aggregate. Complementation of esrC restored these three phenotypes. Two-dimensional gel electrophoresis showed that EsrC regulated the expression of secreted proteins encoded by the TTSS (such as EseB and EseD) and EVP (EvpC) gene clusters. The expression of esrC required a functional two-component system of EsrA-EsrB. EsrC in turn regulated the expression of selected genes encoded in TTSS (such as the transcriptional unit of orf29and orf30, but not esaC) and genes encoded in the EVP gene cluster. The present study sheds light on the regulation of these two key virulence-associated secretion systems and provides greater insight into the pathogenic mechanisms of this bacterium.

Relatively favorable outcomes of post-transplant pulmonary function in patients with chronic myeloid leukemia receiving non-myeloablative allogeneic hematopoietic stem cell transplantation.

Pulmonary function tests were performed in 20 patients with chronic myeloid leukemia before and after human leukocyte antigen-matched allogeneic sibling hematopoietic stem cell transplantation (HSCT) to identify any conditioning treatment effects on post-transplant function from January 1995 to December 2002. Of 20 patients, eight received non-myeloablative conditioning treatment and 12 received conventional myeloablative conditioning treatment. Pulmonary function tests including forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and diffusion capacity for carbon monoxide (DLCO) were performed pretransplant, 6 and 12 months post-transplant. Possible pre-HSCT and post-HSCT risk factors were evaluated for association with pulmonary function. The results showed that myeloablative conditioning treatment had greater negative impact on FEV1, FVC, and DLCO than non-myeloablative conditioning therapy. We conclude that non-myeloablative allogeneic HSCT may apply a better transplant choice in patients who need special concern with post-transplant pulmonary function changes.

Comparative proteomic analysis of extracellular proteins of enterohemorrhagic and enteropathogenic Escherichia coli strains and their ihf and ler mutants.

Enterohemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC, respectively) strains are closely related human pathogens that are responsible for food-borne epidemics in many countries. Integration host factor (IHF) and the locus of enterocyte effacement-encoded regulator (Ler) are needed for the expression of virulence genes in EHEC and EPEC, including the elicitation of actin rearrangements for attaching and effacing lesions. We applied a proteomic approach, using two-dimensional polyacrylamide gel electrophoresis in combination with matrix-assisted laser desorption ionization-time of flight mass spectrometry and a protein database search, to analyze the extracellular protein profiles of EHEC EDL933, EPEC E2348/69, and their ihf and ler mutants. Fifty-nine major protein spots from the extracellular proteomes were identified, including six proteins of unknown function. Twenty-six of them were conserved between EHEC EDL933 and EPEC E2348/69, while some of them were strain-specific proteins. Four common extracellular proteins (EspA, EspB, EspD, and Tir) were regulated by both IHF and Ler in EHEC EDL933 and EPEC E2348/69. TagA in EHEC EDL933 and EspC and EspF in EPEC E2348/69 were present in the wild-type strains but absent from their respective ler and ihf mutants, while FliC was overexpressed in the ihf mutant of EPEC E2348/69. Two dominant forms of EspB were found in EHEC EDL933 and EPEC E2348/69, but the significance of this is unknown. These results show that proteomics is a powerful platform technology for accelerating the understanding of EPEC and EHEC pathogenesis and identifying markers for laboratory diagnoses of these pathogens.

ESHAP as salvage therapy for refractory non-Hodgkin's lymphoma: Taiwan experience.

BACKGROUND: The ESHAP regimen, a combination of the chemotherapeutic drugs etoposide, methylprednisolone (solumedrol), high-dose cytarabine (ara-C) and cisplatin, has been shown to be active against refractory non-Hodgkin's lymphoma in therapeutic trials. We were interested in determining whether this regimen would be effective and tolerable for Chinese patients. METHODS: Thirty-two patients with refractory/relapsed non-Hodgkins lymphoma (23 intermediate-grade and nine high-grade) were enrolled in this study. Etoposide was administered at a dose of 40 mg/m2/day as a 1 h intravenous infusion from day 1 to day 4, solumedrol 500 mg/day was given as a 15 min intravenous infusion from day 1 to day 5, ara-C 2 g/m2 was given as a 2 h intravenous infusion on day 5 and cisplatin was given at a dose of 25 mg/m2/day as a continuous infusion from day 1 to day 4. Clinical efficacy and toxicity were assessed on the basis of the WHO criteria. RESULTS: Ten patients (31.3%, 95% Cl 15.2-47.4%) attained complete remission (CR) and seven had partial remission (PR). The overall response rate was 53.1% (95% Cl 35.8-70.4%). In eight of the 10 CR patients, the remission lasted for more than 8 months. The remaining two patients had CR of 5 and 6 months. The median duration of CR was 12.2 months (range 5-22 months). Myelosuppression with subsequent infections was the major toxicity. Severe leukopenia (WBC < 1000/microliter) lasted for an average of 12 days and thrombocytopenia (< 25,000/microliter) 18 days. One patient (3.1%) died of neutropenia-associated sepsis within 4 weeks after treatment. Non-myeloid toxicities included alopecia in 66% (28% grade 2, 22% grade 3), stomatitis in 72% (25% grade 2, 28% grade 3, 13% grade 4), hepatotoxicity in 9% (3% grade 2), renal toxicity in 13% (6% grade 2, 3% grade 3) and infection in 56% (18% grade 2, 25% grade 3, 13% grade 4). The majority of the responders relapsed within 2 years after ESHAP treatment. Median survival for all patients was 8.6 months. CONCLUSIONS: ESHAP is an active and tolerable regimen in Chinese patients with relapsed/refractory lymphoma, but the duration of remission is brief and without significant impact on survival.

Toxic cardiogenic shock in a patient receiving weekly 24-h infusion of high-dose 5-fluorouracil and leucovorin.

A 54-year-old man was treated with weekly 24-h infusion of high-dose 5-fluorouracil (2600 mg/m2) and leucovorin (100 mg/m2) for metastatic colon cancer. At first, he tolerated the treatment well and no significant toxicity was identified. After a total of eight courses of treatment, a stable disease was observed, but mild shortness of breath was found on occasion. The patient had no previous history of cardiac disease and the heart performance assessed by left ventricular ejection fraction before treatment was normal. Unfortunately, acute pulmonary edema with lethal cardiogenic shock occurred during the ninth course of treatment, in spite of intensive medical treatment. The chest X-ray showed extreme cardiomegaly. Repeated assessment of his heart function by echocardiogram and ventricular ejection fraction revealed a very poor cardiac performance. Toxic cardiogenic shock during weekly 24-h infusion of high-dose 5-fluorouracil and leucovorin is extremely rare. To the best of our knowledge, no case has been reported in the English literature. We report a case and the relevant literature about the incidence, clinical picture and possible pathophysiology on 5-fluorouracil-related cardioxicity is reviewed.

Phase II study of the modified regimen of etoposide, leucovorin and 5-fluorouracil for patients with advanced gastric cancer.

BACKGROUND: The efficacy of the treatment of advanced gastric cancer is not very good. The response rate to the original etoposide--leucovorin--5-fluorouracil (ELF) treatment is 53% with tolerable side effects. Whether increasing the dose intensity by prolonging the duration of infusion with 5-fluorouracil (5-FU) and leucovorin (LV) from 3 to 5 days for advanced or metastatic gastric cancer patients would enhance the efficacy but not increase side effects is still unknown. METHODS: Thirty-six advanced or metastatic gastric cancer and chemotherapy-naïve patients with measurable or evaluable diseases were scheduled to receive intravenous etoposide 100 mg/m2/day on days 2-4, LV 300 mg/m2/day intravenously and 5-FU 500 mg/m2/day intravenously on days 1-5, every 4 weeks. All patients who received at least two courses of chemotherapy were evaluated for tumor response, survival and response duration and toxicity according to the WHO criteria. RESULTS: Thirteen patients showed a response, including five with complete response (CR). The overall response rate was 36% (95% confidence interval, CI, 20-52%) in the whole group and 46% (95% CI 28-66%) in the 28 patients with measurable disease. The median progression-free interval and overall median survival time were 5 and 7 months, respectively. The most frequent toxicity was alopecia (grade I/II 56.3%). The incidence of grade III or greater myelosuppression was 5.9%. No treatment-related death occurred. CONCLUSIONS: The efficacy of the modified ELF by increasing the dosages of 5-FU and LV is not superior to the results of the original regimen, yet it is a relatively safe and tolerable combination regimen for advanced gastric cancer.

Navoban (tropisetron, ICS 205-930) and dexamethasone combination in the prevention of vomiting for patients receiving preconditioning high-dose chemotherapy before marrow transplantation.

The anti-emetic efficacy of a combination of tropisetron and dexamethasone was studied in 33 patients who underwent bone marrow transplantation. Another 50 patients receiving conventional anti-emetic therapies in bone marrow transplantation served as control. On the first and second days of preconditioning chemotherapy, 51% and 36% respectively of patients in the tropisetron and dexamethasone group did not experience vomiting, compared with only 12% and 10% of control group patients (P < 0.001). The mean number of episodes of vomiting in the tropisetron and dexamethasone group was also significantly lower than in the control group (0.97+/-1.65 vs 3.50+/-2.45 and 1.30+/-1.40 vs 4.44+/-2.91 respectively, both P < 0.001). Control of vomiting in the two groups was not significantly different during days 3-6. Analysis of patients receiving busulfan and cyclophosphamide as the preconditioning regimen still showed better anti-emetic control in the tropisetron and dexamethasone group than in the control group on the first two days of treatment (total control rate 33.3% vs 6.5% and 44.4% vs 12.9% respectively, P < 0.001). Patients given tropisetron and dexamethasone combination more frequently suffered from dizziness and burning sensation of the chest. However, diarrhea and extrapyramidal symptoms were the most frequent adverse effects seen after using conventional anti-emetic combination. The combination of tropisetron and dexamethasone was thus superior to conventional anti-emetic combinations in preventing vomiting during preconditioning period of bone marrow transplantation. The adverse effects of this combination were minimal and well tolerated by patients.

Treatment of previously treated metastatic breast cancer by mitoxantrone and 48-hour continuous infusion of high-dose 5-FU and leucovorin (MFL): low palliative benefit and high treatment-related toxicity.

For previously treated advanced breast cancer, there is no standard second-line therapy. Combination chemotherapy with mitoxantrone, high-dose 5-fluorouracil (5-FU) and leucovorin (MFL regimen) had been reported as an effective and well tolerated regimen. From October 1993 to November 1995, we treated 13 patients with previously chemotherapy-treated metastatic breast cancer by mitoxantrone, 12 mg/m2, on day 1 and continuous infusion of 5-FU, 3000 mg/m2, together with leucovorin, 300 mg/m2, for 48 h from day 1 to 2. Each course of chemotherapy was given every 4 weeks. Most of these patients had more than two metastatic sites, with lung metastasis predominant. Seven patients had been treated with anthracycline. Seven patients had previously received radiotherapy and seven had received hormone therapy. Median number of courses of MFL regimen given was six and the median cumulative dose of mitoxantrone was 68.35 mg/m2. One patient had complete response, seven had stable disease, none had partial response and five had progressive disease. The overall objective response rate was 7.6%. The median follow-up period was 14 months. Median survival was 16 months. Median progression-free survival was 5 months. A complete responder had relapse-free survival up to 17 months. Major toxicities were cardiotoxicity and leukopenia. Eight patients were dead in the last follow-up; two of them died of treatment-related toxicity. The MFL regimen achieves little palliative benefit and induces severe toxicity at a fairly high rate. Administration of this regimen to breast cancer patients who have been treated by chemotherapy and those with impaired heart function requires careful attention.

Unusual electroencephalographic findings in subacute sclerosing panencephalitis: a case report.

Subacute sclerosing panencephalitis (SSPE) is a rare infectious central nervous system (CNS) disease with a poor prognosis. We reported on the case of an adolescent girl with SSPE and characteristic periodic electroencephalographic (EEG) complexes. Her neurological deficits including generalized myoclonic seizures improved after intraventricular interferon (IFN) treatment. However, unusual EEG patterns consisting of bisynchronous occipital spikes preceding periodic complexes developed in follow-up EEGs.

Bone marrow transplantation with HLA partially matched related donors.

BACKGROUND: Approximately one-fourth of patients who could benefit from bone marrow transplantation (BMT) are served by a genotypically identical sibling donor. When patients do not have an HLA-matched donor, alternative marrow sources should be explored. The way to allow survival in some patients is to perform two- or three loci HLA mismatched BMT. Preliminary results with BMT in partially-matched, related donors performed at Veterans General Hospital-Taipei are reported. METHODS: Between 1985 and 1994, a total of 121 patients were enrolled in this study. Ten patients received BMT with HLA partially-matched, related donor, including 2 acute nonlymphocytic leukemia (ANLL), 5 chronic myelocytic leukemia (CML) and 3 severe aplastic anemia (SAA). Three and four hematologically malignant patients received cyclophosphamide (Cy) + radiotherapy (RT) and Cy + Busulfan(Bu) preconditioning regimens, respectively; three SAA patients received standard Cy + RT regimen. Additional prophylaxis against graft-versus-host disease (GVHD) consisted of methotrexate (MTX) and cyclosporin-A (CSA). The median follow up was 36 months. Seven were 2-loci disparate and 3 were 3-loci. RESULTS: Engraftment developed with a mean of 20.9 days after transplant. Nonengraftment rate was 1/10 (10%), delayed graft failure 2/10(20%) and venoocculsive disease (VOD) 1/10(10%). The percentage of patients who developed grade II to IV acute GVHD was low (13.6% of those mismatched at 0 locus, 31.6% mismatched at 1 loci and 14.3% at > or = 2 loci. p = 0.181). Extensive chronic GVHD occurred in 16.7% (34.1% of those mismatched at 0 locus, 41.2% mismatched at 1 loci and 16.7% at 2 loci. p = 0.492). There were five deaths. The other 5 still survived at 36 months of follow-up. Log-rank analysis revealed no statistical significance between those mismatched at > or = 2 vs at 1 (p = 0.146) but the difference between those mismatched at > or = 2 and at 0 (p = 0.0359) was statistically significant. CONCLUSIONS: When patients requiring BMT without an HLA identical sibling donor, an alternative transplant from haploidentical family members remains a viable option, especially when a patient has CML, SAA or other refractory hematologic malignancies.

An econometric analysis of the effects of population change on economic growth: a study of Taiwan.

PIP: This study used an econometric model, estimated from time series data, to evaluate the effects of demographic factors on the T aiwanese economy. The simulation results suggest that, in the short run, a stationary population produces significantly higher income per capita than rapid population growth; in the long run, however, rapid population growth produces a slightly higher income per capita. Under assumptions of very low fertility trends, the population size, equivalent adult consumers, and labor force can be expected to grow by no more than 50% in a century, whereas under the very high fertility trend assumptions, they would more than double. The reason that lower fertility populations produce a smaller gross domestic product per capita in the long run than the normal fertility population is that the negative effects of a slower growing labor force dominate the positive effects of a faster growing capital formation. In terms of the present values of annual income per capita, the slow growing population shows considerably better economic performance. Given the immediate economic advantages of lower fertility, it is important for developing countries with high birth rates to reduce fertility in order to produce higher per capita income effects and break out of poverty. It is considered of little importance that the slow growing populations eventually produce slightly smaller per capita.^ieng

The rapid fertility decline in Guam natives.

PIP: Since the end of World War II, the Guam native population, who are mostly Roman Catholics, has undergone 1 of the most dramatic socioeconomic developments ever recorded, turning completely from a subsistence to a wage economy within a few decades. They have rapidly become incorporated into the dominant American culture and economy. This accelerated process of modernization has been accompanied by a very sharp fertility decline. Surprisingly, from 1950 to 1960, fertility declined dramatically in the absence of a family planning program. The estimated fertility rates for Guam natives in 1950, 1960, 1970 and 1977, illustrate this decline. The TFR for Guam natives declined 12% from 7282 children/1000 women of reproductive age in 1950, to 6414 in 1960. By 1977, it was only 1/2 of the 1950 rate. The general fertility rate followed a similar pattern, dropping 48%, from 219 to 113, over the period 1950-77. The family planning program, inaugurated in 1968, probably facilitated the rapid fertility decline since 1970. Although nearly 1/2 the decline in the crude birth rate from 1950 to 1960 is attributable to changes in the age structure, this is not thought to be the explanation for the 43% decline from 1950-77, as shown by the age-standardized crude birth rate using the 1950 population as the standard. The trend of fertility decline for Guam natives was similar to that for developing countries with dramatic fertility reduction during the modernization process, e.g., South Korea, Taiwan and Hong Kong. The fertility trend of Guam natives is a good example of other findings that fertility declines often occur at points of intersection of major cultures as well as on islands, which are maybe more readily susceptible to outside influence. Many conditions favorable to a fertility decline on Guam are present, namely those arising from contact with mainstream American culture. They include a rising age at marriage as women increasingly participate in the labor force and achieve higher educational levels. A KAP study relative to family planning among native Guam women, found increasing use of contraceptive devices among them, regardless of their Church's opposition. It is suggested that the increasing defection of Guam Roman Catholic women from the teachings of their Church on the subject of birth control has been 1 main reason for the observed fertility decline.^ieng