Implementation of an interprofessional team-based learning program involving seven undergraduate health and social care programs from two universities, and students' evaluation of their readiness for interprofessional learning.

BACKGROUND: Interprofessional learning is gaining momentum in revolutionizing healthcare education. During the academic year 2015/16, seven undergraduate-entry health and social care programs from two universities in Hong Kong took part in an interprofessional education program. Based on considerations such as the large number of students involved and the need to incorporate adult learning principles, team-based learning was adopted as the pedagogy for the program, which was therefore called the interprofessional team-based learning program (IPTBL). The authors describe the development and implementation of the IPTBL program and evaluate the effectiveness of the program implementation. METHODS: Eight hundred and one students, who are predominantly Chinese, participated in the IPTBL. The quantitative design (a pretest-posttest experimental design) was utilized to examine the students' gains on their readiness to engage in interprofessional education (IPE). RESULTS: Three instructional units (IUs) were implemented, each around a clinical area which could engage students from complementary health and social care disciplines. Each IU followed a team-based learning (TBL) process: pre-class study, individual readiness assurance test, team readiness assurance test, appeal, feedback, and application exercise. An electronic platform was developed and was progressively introduced in the three IUs. The students' self-perceived attainment of the IPE learning outcomes was high. Across all four subscales of RIPLS, there was significant improvement in student's readiness to engage in interprofessional learning after the IPTBL. A number of challenges were identified: significant time involvement of the teachers, difficulty in matching students from different programs, difficulty in making IPTBL count towards a summative assessment score, difficulty in developing the LAMS platform, logistics difficulty in managing paper TBL, and inappropriateness of the venue. CONCLUSIONS: Despite some challenges in developing and implementing the IPTBL program, our experience showed that TBL is a viable pedagogy to be used in interprofessional education involving hundreds of students. The significant improvement in all four subscales of RIPLS showed the effects of the IPTBL program in preparing students for collaborative practice. Factors that contributed to the success of the use of TBL for IPE are discussed.

EM23, a natural sesquiterpene lactone, targets thioredoxin reductase to activate JNK and cell death pathways in human cervical cancer cells.

Sesquiterpene lactones (SLs) are the active constituents of a variety of medicinal plants and found to have potential anticancer activities. However, the intracellular molecular targets of SLs and the underlying molecular mechanisms have not been well elucidated. In this study, we observed that EM23, a natural SL, exhibited anti-cancer activity in human cervical cancer cell lines by inducing apoptosis as indicated by caspase 3 activation, XIAP downregulation and mitochondrial dysfunction. Mechanistic studies indicated that EM23-induced apoptosis was mediated by reactive oxygen species (ROS) and the knockdown of thioredoxin (Trx) or thioredoxin reductase (TrxR) resulted in a reduction in apoptosis. EM23 attenuated TrxR activity by alkylation of C-terminal redox-active site Sec498 of TrxR and inhibited the expression levels of Trx/TrxR to facilitate ROS accumulation. Furthermore, inhibition of Trx/TrxR system resulted in the dissociation of ASK1 from Trx and the downstream activation of JNK. Pretreatment with ASK1/JNK inhibitors partially rescued cells from EM23-induced apoptosis. Additionally, EM23 inhibited Akt/mTOR pathway and induced autophagy, which was observed to be proapoptotic and mediated by ROS. Together, these results reveal a potential molecular mechanism for the apoptotic induction observed with SL compound EM23, and emphasize its putative role as a therapeutic agent for human cervical cancer.

B5, a thioredoxin reductase inhibitor, induces apoptosis in human cervical cancer cells by suppressing the thioredoxin system, disrupting mitochondrion-dependent pathways and triggering autophagy.

The synthetic curcumin analog B5 is a potent inhibitor of thioredoxin reductase (TrxR) that has potential anticancer effects. The molecular mechanism underlying B5 as an anticancer agent is not yet fully understood. In this study, we report that B5 induces apoptosis in two human cervical cancer cell lines, CaSki and SiHa, as evidenced by the downregulation of XIAP, activation of caspases and cleavage of PARP. The involvement of the mitochondrial pathway in B5-induced apoptosis was suggested by the dissipation of mitochondrial membrane potential and increased expression of pro-apoptotic Bcl-2 family proteins. In B5-treated cells, TrxR activity was markedly inhibited with concomitant accumulation of oxidized thioredoxin, increased formation of reactive oxygen species (ROS), and activation of ASK1 and its downstream regulatory target p38/JNK. B5-induced apoptosis was significantly inhibited in the presence of N-acetyl-l-cysteine. Microscopic examination of B5-treated cells revealed increased presence of cytoplasmic vacuoles. The ability of B5 to activate autophagy in cells was subsequently confirmed by cell staining with acridine orange, accumulation of LC3-II, and measurement of autophagic flux. Unlike B5-induced apoptosis, autophagy induced by B5 is not ROS-mediated but a role for the AKT and AMPK signaling pathways is implied. In SiHa cells but not CaSki cells, B5-induced apoptosis was promoted by autophagy. These data suggest that the anticarcinogenic effects of B5 is mediated by complex interplay between cellular mechanisms governing redox homeostasis, apoptosis and autophagy.

Cholesterol-induced mammary tumorigenesis is enhanced by adiponectin deficiency: role of LDL receptor upregulation.

Adiponectin is an adipokine that can suppress the proliferation of various human carcinoma cells. Although its anti-tumor activities have been suggested by many clinical investigations and animal studies, the underlying mechanisms are not fully characterized. In MMTV-polyomavirus middle T antigen (MMTV-PyVT) transgenic mice models, reduced- or complete loss-of-adiponectin expression promotes mammary tumor development. The present study demonstrated that while tumor development in control MMTV-PyVT mice is associated with a progressively decreased circulating cholesterol concentration, adiponectin deficient MMTV-PyVT mice showed significantly elevated total- and low density lipoprotein (LDL)-cholesterol levels. Cholesterol contents in tumors derived from adiponectin deficient mice were dramatically augmented. High fat high cholesterol diet further accelerated the tumor development in adiponectin deficient PyVT mice. The protein levels of LDL receptor (LDLR) were found to be upregulated in adiponectin-deficient tumor cells. In human breast carcinoma cells, treatment with LDL-cholesterol or overexpressing LDLR elevates nuclear beta-catenin activity and facilitates tumor cell proliferation. On the other hand, adiponectin decreased LDLR protein expression in breast cancer cells and inhibited LDL-cholesterol-induced tumor cell proliferation. Both in vivo and in vitro evidence demonstrated a stimulatory effect of adiponectin on autophagy process, which mediated the down-regulation of LDLR. Adiponectin-induced reduction of LDLR was blocked by treatment with a specific inhibitor of autophagy, 3-methyladenine. In conclusion, the study demonstrates that adiponectin elicits tumor suppressive effects by modulating cholesterol homeostasis and LDLR expression in breast cancer cells, which is at least in part attributed to its role in promoting autophagic flux.

ProteoMirExpress: inferring microRNA and protein-centered regulatory networks from high-throughput proteomic and mRNA expression data.

MicroRNAs (miRNAs) regulate gene expression through translational repression and RNA degradation. Recently developed high-throughput proteomic methods measure gene expression changes at protein level and therefore can reveal the direct effects of miRNAs' translational repression. Here, we present a web server, ProteoMirExpress, that integrates proteomic and mRNA expression data together to infer miRNA-centered regulatory networks. With both types of high-throughput data from the users, ProteoMirExpress is able to discover not only miRNA targets that have decreased mRNA, but also subgroups of targets with suppressed proteins whose mRNAs are not significantly changed or with decreased mRNA whose proteins are not significantly changed, which are usually ignored by most current methods. Furthermore, both direct and indirect targets of miRNAs can be detected. Therefore, ProteoMirExpress provides more comprehensive miRNA-centered regulatory networks. We used several published data to assess the quality of our inferred networks and prove the value of our server. ProteoMirExpress is available online, with free access to academic users.

Adiponectin haploinsufficiency promotes mammary tumor development in MMTV-PyVT mice by modulation of phosphatase and tensin homolog activities.

BACKGROUND: Adiponectin is an adipokine possessing beneficial effects on obesity-related medical complications. A negative association of adiponectin levels with breast cancer development has been demonstrated. However, the precise role of adiponectin deficiency in mammary carcinogenesis remains elusive. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, MMTV-polyomavirus middle T antigen (MMTV-PyVT) transgenic mice with reduced adiponectin expressions were established and the stromal effects of adiponectin haploinsufficiency on mammary tumor development evaluated. In mice from both FVB/N and C57BL/6J backgrounds, insufficient adiponectin production promoted mammary tumor onset and development. A distinctive basal-like subtype of tumors, with a more aggressive phenotype, was derived from adiponectin haplodeficient MMTV-PyVT mice. Comparing with those from control MMTV-PyVT mice, the isolated mammary tumor cells showed enhanced tumor progression in re-implanted nude mice, accelerated proliferation in primary cultures, and hyperactivated phosphatidylinositol-3-kinase (PI3K)/Akt/beta-catenin signaling, which at least partly attributed to the decreased phosphatase and tensin homolog (PTEN) activities. Further analysis revealed that PTEN was inactivated by a redox-regulated mechanism. Increased association of PTEN-thioredoxin complexes was detected in tumors derived from mice with reduced adiponectin levels. The activities of thioredoxin (Trx1) and thioredoxin reductase (TrxR1) were significantly elevated, whereas treatment with either curcumin, an irreversible inhibitor of TrxR1, or adiponectin largely attenuated their activities and resulted in the re-activation of PTEN in these tumor cells. Moreover, adiponectin could inhibit TrxR1 promoter-mediated transcription and restore the mRNA expressions of TrxR1. CONCLUSION: Adiponectin haploinsufficiency facilitated mammary tumorigenesis by down-regulation of PTEN activity and activation of PI3K/Akt signalling pathway through a mechanism involving Trx1/TrxR1 redox regulations.

The PERK/eIF2 alpha signaling pathway of Unfolded Protein Response is essential for N-(4-hydroxyphenyl)retinamide (4HPR)-induced cytotoxicity in cancer cells.

N-(4-hydroxyphenyl)retinamide (4HPR) is a synthetic retinoid that has been tested in clinical trials as a cancer chemopreventive drug. 4HPR is cytotoxic to cancer cells but the underlying molecular mechanisms are at present only partially understood. Here we demonstrate that in the human cervical cancer cell line HeLa and the human leukemia cell line HL-60, 4HPR caused rapid, Reactive Oxygen Species (ROS)-dependent activation of the Unfolded Protein Response (UPR). In HeLa cells, 4HPR was shown to induce cell death and activation of procaspases. These effects of 4HPR could be abolished by the over-expression of dominant negative mutants of PERK or eIF2 alpha. HeLa cells incubated with 4HPR were found to form autophagosomes that were also mediated by the PERK/eIF2 alpha pathway. While 4HPR-induced cell death could be significantly prevented by the presence of specific caspase inhibitors, 3-methyladenine (3-MA) that inhibits autophagosome formation enhanced 4HPR-induced cell death. Examination of individual 4HPR-treated HeLa cells revealed that those without the development of autophagosomes hence exhibiting an incomplete UPR were caspase-active and were not viable, while those with autophagosomes were caspase-inactive and retained cell viability. Our data suggest that the PERK/eIF2 alpha pathway is essential for the cytotoxicity of 4HPR that targets on cancer cells with malfunctional UPR.

ROS mediates 4HPR-induced posttranscriptional expression of the Gadd153 gene.

All-trans-N-(4-hydroxyphenyl)retinamide (4HPR) is a synthetic retinoid that can induce apoptosis in many cancer cell lines. The cytotoxicity of 4HPR is dependent on the production of ROS but the underlying reasons are not entirely certain. We have investigated the role of 4HPR-induced production of ROS in mediating the expression of the recently identified 4HPR-responsive gene Gadd153. In 4HPR-treated cells, the elevation of Gadd153 protein level was prevented by vitamin C, which had no effect on the activation of the Gadd153 gene promoter. The 4HPR-induced elevation of Gadd153 mRNA level persisted even after transcription was blocked with actinomycin D, but declined rapidly upon the addition of antioxidants to the transcription-arrested cells. The mRNA expressed from the full-length Gadd153 cDNA was degraded constitutively in cells in the absence but not in the presence of 4HPR. Such an inhibitory effect of 4HPR was abolished by antioxidants and by inhibitors of 12-lipoxygenase, baicalein (specific) and esculetin (panspecific). The inhibition of 4HPR-induced expression of Gadd153 protein by vitamin C was independent of intracellular proteasome activity and vitamin C had no effect on the intracellular decay of Gadd153 protein. Our data provide the first evidence that the posttranscriptional expression of the Gadd153 gene can be regulated by ROS produced by 4HPR.

Upregulation of GADD153 expression in the apoptotic signaling of N-(4-hydroxyphenyl)retinamide (4HPR).

The molecular basis for the pharmacologic effects of N-(4-hydroxyphenyl)retinamide (4HPR) was investigated by studying the gene(s) that this compound may upregulate in cultured human epithelial tumor cells. Treatment of the cultured human nasopharyngeal carcinoma-derived cells (CNE3) with 4HPR caused modest cell-cycle arrest at G(1) and apoptosis. The mRNA levels of a total of 20 genes were downregulated with the majority of them involved in cell cycle-related functions. Only the mRNA level of the growth arrest and DNA-damage inducible gene (gadd153) was upregulated by approximately 7-fold, with a concomitant increase in intracellular protein level. Similar upregulation of gadd153 by 4HPR was observed in HeLa and 2 other tumor cell lines. The 4HPR-induced apoptosis was markedly enhanced in the CNE3 cells that transiently overexpressed the gadd153 protein. Unlike 4HPR, all-trans-retinoic acid (ATRA) had no effect on the mRNA or protein level of gadd153. The ability of 4HPR and ATRA to stimulate the promoter activity of gadd153 was then examined. In the HeLa cells, both 4HPR and ATRA caused a 2- to 4-fold stimulation of the promoter activity of gadd153, but similar to the CNE3 cells, ATRA was incapable of upregulating the protein level of gadd153. This is the first demonstration that gadd153 is a 4HPR-responsive gene in tumor cells and may have a functional role to play in 4HPR-induced apoptosis. Furthermore, our data suggest that the expression of gadd153 can be regulated by 4HPR at the transcriptional level.