Propolin G-Suppressed Epithelial-to-Mesenchymal Transition in Triple-Negative Breast Cancer Cells via Glycogen Synthase Kinase 3β-Mediated Snail and HDAC6-Regulated Vimentin Degradation

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer with a poor prognosis. The incidence and mortality rate of TNBC are frequently found in younger women. Due to the absence of a good therapeutic strategy, effective remedies for inhibiting TNBC have been developed for improving the cure rate. Epithelial-to-mesenchymal transition (EMT) is a critical mechanism to regulate cancer cell motility and invasion. Furthermore, ectopic expression of EMT molecules correlates with the metastasis and poor prognosis of TNBC. Targeting EMT might be a strategy for the therapy and prevention of TNBC. Propolin G, an active c-prenylflavanone in Taiwanese propolis, has been shown to possess anti-cancer activity in many cancers. However, the anti-metastasis activity of propolin G on TNBC is still unclear. The present study showed that the migration and invasion activities of TNBC cells was suppressed by propolin G. Down-regulated expression of Snail and vimentin and up-regulated expression of E-cadherin were dose- and time-dependently observed in propolin G-treated MDA-MB-231 cells. Propolin G inhibited Snail and vimentin expressions via the signaling pathways associated with post-translational modification. The activation of glycogen synthase kinase 3β (GSK-3β) by propolin G resulted in increasing GSK-3β interaction with Snail. Consequently, the nuclear localization and stability of Snail was disrupted resulting in promoting the degradation. Propolin G-inhibited Snail expression and the activities of migration and invasion were reversed by GSK-3β inhibitor pretreatment. Meanwhile, the outcomes also revealed that histone deacetylase 6 (HDAC6) activity was dose-dependently suppressed by propolin G. Correspondently, the amounts of acetyl-α-tubulin, a down-stream substrate of HDAC6, were increased. Dissociation of HDAC6/Hsp90 with vimentin leading to increased vimentin acetylation and degradation was perceived in the cells with the addition of propolin G. Moreover, up-regulated expression of acetyl-α-tubulin by propolin G was attenuated by HDAC6 overexpression. On the contrary, down-regulated expression of vimentin, cell migration and invasion by propolin G were overturned by HDAC6 overexpression. Conclusively, restraint cell migration and invasion of TNBC by propolin G were activated by the expression of GSK-3β-suppressed Snail and the interruption of HDAC6-mediated vimentin protein stability. Aiming at EMT, propolin G might be a potential candidate for TNBC therapy.

Suppressing migration and invasion of H1299 lung cancer cells by honokiol through disrupting expression of an HDAC6-mediated matrix metalloproteinase 9

Metastasis is the crucial mechanism to cause high mortality in lung cancer. Degradation of extracellular matrix (ECM) by proteolytic enzymes, especially matrix metalloproteinases (MMPs), is a key process for promoting cancer cell migration and invasion. Therefore, targeting MMPs might be a strategy for lung cancer metastasis suppression. Honokiol, a biological active component of Magnolia officinalis, has been indicated to suppress lung cancer tumorigenesis through epigenetic regulation. However, the regulation of MMPs‐mediated migration and invasion by honokiol through epigenetic regulation in lung cancer is still a mystery. In the present study, the migration and invasion ability of H1299 lung cancer was suppressed by noncytotoxic concentrations of honokiol treatment. The proteolytic activity of MMP‐9, rather than MMP‐2, was inhibited in honokiol‐treated H1299 cells. Honokiol‐inhibited MMP‐9 expression was through promoting MMP‐9 protein degradation rather than suppressing transcription mechanism. Furthermore, the expression of specific histone deacetylases 6 (HDAC6) substrate, acetyl‐α‐tubulin, was accumulated after honokiol incubation. The disassociation of MMP‐9 with hyper‐acetylated heat shock protein 90 (Hsp90) was observed resulting in MMP‐9 degradation after honokiol treatment. Meanwhile, honokiol‐suppressed MMP‐9 expression and invasion ability of H1299 lung cancer cells was rescued by HDAC6 overexpression. Accordingly, the results suggested that the suppression of migration and invasion activities by honokiol was through inhibiting HDAC6‐mediated Hsp90/MMP‐9 interaction and followed by MMP‐9 degradation in lung cancer.

Emergency visits among end-of-life cancer patients in Taiwan: a nationwide population-based study

BACKGROUND

An increased number of emergency visits at the end of life may indicate poor-quality cancer care. The study aimed to investigate the prevalence and utilization of emergency visits and to explore the reasons for emergency department (ED) visits among cancer patients at the end of life.

METHODS

A retrospective cohort study was performed by tracking one year of ambulatory medical service records before death. Data were collected from the cancer dataset of Taiwan's National Health Insurance Research Database (NHIRD).

RESULTS

A total of 32,772 (19.2%) patients with malignant cancer visited EDs, and 23,883 patients died during the study period. Of these, the prevalence of emergency visits in the mortality group was 81.5%, and their ED utilization was significantly increased monthly to the end of life. The most frequent types of cancer were digestive and peritoneum cancers (34.8%), followed by breast cancer (17.7%) and head and neck cancers (13.3%). Older patients, males, and those diagnosed with metastases, respiratory or digestive cancer were more likely to use ED services at the end of life. Use of an ED service in the nearest community hospital to replace medical centers for dying cancer patients would be more acceptable in emergency situations.

CONCLUSIONS

Our study provided population-based evidence related to ED utilization. An understanding of the reasons for such visits could be useful in preventing overuse of ED visits to improve the quality of end-of-life care.

Leukocytosis in polycythemia vera and splenomegaly in essential thrombocythemia are independent risk factors for hemorrhage

BACKGROUND

Long-term outcomes are favorable for patients with polycythemia vera (PV) and for patients with essential thrombocythemia (ET). However, hemorrhage is a significant cause of morbidity and mortality in those patients.

METHODS

We retrospectively recruited 247 patients who had received a diagnosis of PV (n = 101) or ET (n = 146) during the period 2001-2010.

RESULTS

After a median follow-up period of 36.2 months, the cumulative incidence of hemorrhage was 39.6% in patients with PV (6.2% per person-year) and 29.7% in patients with ET (5.9% person-years). Episodes of major bleeding occurred in 9.9% of patients with PV and in 14.4% of patients with ET. Overall survival was significantly shorter among patients with hemorrhage than among those without said complication (P < 0.001 for overall patients; P = 0.002 for patients with PV; P = 0.026 for patients with ET). In the univariate analysis, age ≥ 60 yr (OR: 4.77, P = 0.046) and WBC ≥ 16 × 10(9) /L (OR: 4.15, P = 0.010) were predictors of hemorrhage in patients with PV, and age ≥ 60 yr (OR: 3.25, P = 0.040), WBC ≥ 16 × 10(9) /L (OR: 2.89, P = 0.024), albumin <4.0 g/dL (OR: 4.10, P = 0.002), and splenomegaly (OR: 5.19, P = 0.002) were predictors of hemorrhage in patients with ET. Multivariate analysis showed that WBC ≥ 16 × 10(9) /L was the only significant risk factor for hemorrhage in patients with PV (OR: 3.51, P = 0.026) and that splenomegaly was the only risk factor for hemorrhage in patients with ET (OR: 3.00, P = 0.048).

CONCLUSION

Leukocytosis in PV and splenomegaly in ET are independent risk factors for hemorrhage.

Comparison of surgical resection and transarterial chemoembolization for hepatocellular carcinoma beyond the Milan criteria: a propensity score analysis

BACKGROUND

Treatment for patients with intermediate-stage hepatocellular carcinoma (HCC) is controversial. This study compared the long-term survival of patients beyond the Milan criteria who received surgical resection (SR) or transarterial chemoembolization (TACE).

METHODS

A total of 268 and 455 HCC patients beyond the Milan criteria undergoing SR and TACE, respectively, were retrospectively evaluated. After propensity score analysis to adjust for baseline differences, 146 pairs of matched patients were selected from each treatment arm. Long-term survival was compared by the Kaplan-Meier method. Independent prognostic predictors were determined by the Cox proportional hazards model.

RESULTS

Long-term survival was significantly better for the SR group by univariate survival analysis (P < .001). In the Cox model, SR was identified as an independent predictor of better prognosis (hazard ratio = 0.3, 95% confidence interval [95% CI]: 0.23-0.4; P < .001). Despite similar baseline characteristics in the propensity score model, patients who underwent SR had significantly better survival than patients who underwent TACE (P < .001). Patients receiving TACE had 2.56-fold increased risk of long-term mortality in the propensity model (95% CI: 1.73-3.78). The SR and TACE groups had comparable 30- and 90-day posttreatment mortality. The Cox model consistently disclosed the significant superiority of SR in terms of long-term survival in the propensity score model (P < .001).

CONCLUSIONS

For HCC patients beyond the Milan criteria, SR is considered equally safe as TACE and provides better long-term survival. SR may be regarded as the priority treatment for these patients.

Chronic hepatitis virus infection in patients with multiple myeloma: clinical characteristics and outcomes

OBJECTIVES

Cytotoxic agents and steroids are used to treat lymphoid malignancies, but these compounds may exacerbate chronic viral hepatitis. For patients with multiple myeloma, the impact of preexisting hepatitis virus infection is unclear. The aim of this study is to explore the characteristics and outcomes of myeloma patients with chronic hepatitis virus infection.

METHODS

From 2003 to 2008, 155 myeloma patients were examined to determine their chronic hepatitis virus infection statuses using serologic tests for the hepatitis B (HBV) and C viruses (HCV). Clinical parameters and outcome variables were retrieved via a medical chart review.

RESULTS

The estimated prevalences of chronic HBV and HCV infections were 11.0% (n = 17) and 9.0% (n = 14), respectively. The characteristics of patients who were hepatitis virus carriers and those who were not were similar. However, carrier patients had a higher prevalence of conventional cytogenetic abnormalities (64.3% vs. 25.0%). The cumulative incidences of grade 3-4 elevation of the level of alanine transaminase, 30.0% vs. 12.0%, and hyperbilirubinemia, 20.0% vs. 1.6%, were higher in carriers as well. In a Kaplan-Meier analysis, carrier patients had worse overall survival (median: 16.0 vs. 42.4 months). The prognostic value of carrier status was not statistically significant in the multivariate analysis, but an age of more than 65 years old, the presence of cytogenetic abnormalities, a beta-2-microglobulin level of more than 3.5 mg/L, and a serum creatinine level of more than 2 mg/ dL were independent factors associated with poor prognosis.

CONCLUSION

Myeloma patients with chronic hepatitis virus infections might be a distinct subgroup, and close monitoring of hepatic adverse events should be mandatory.

Clinical features and prognostic factors of angioimmunoblastic T-cell lymphoma in Taiwan: a single-institution experience

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of peripheral T-cell lymphoma that carries a poor prognosis. This study retrospectively analyzed patients with AITL from a single institution in Taiwan, aiming to define the clinical features and prognostic factors. Patients with AITL treated at our institution from February 1988 through January 2010 were enrolled. Factors associated with overall survival (OS) were determined by statistical methods. A total of 31 Taiwanese patients (21 males) were identified. The median age was 74 years (range, 27-90). Among all patients, 67.7% were Ann Arbor stage III or IV, 58.1% presented with B symptoms, 48.4% had hypoalbuminenia (<35 g/L), and 63.3% had elevated lactate dehydrogenase (LDH) at diagnosis. First-line chemotherapy was mostly CHOP (cyclophosphamide, vincristine, doxorubicin, and prednisolone)-based and complete response (CR) was achieved in 25% of patients. The actuarial 2-year survival rate was 38.7%, and the median OS was 14.9 months. In multivariate analysis, initial presentation with fever (p = 0.035), advanced stage (p = 0.024), and failure to achieve CR (p = 0.029) were independent adverse factors associated with poorer OS. Interestingly, OS did not differ whether chemotherapy regimens contained anthracycline or not. Taiwanese patients with AITL were usually elderly. Despite the prognosis being generally poor, patients with AITL should be treated with the goal of achieving CR, regardless of anthracycline- or non-anthracycline-based chemotherapy.

Identification of endothelial genes up-regulated in vivo

We have used microarrays to identify genes that are selectively expressed in endothelial cells in vivo. Analysis of freshly isolated endothelial cells from the lungs and kidneys reveals that 350 out of the 10,000 genes represented on the microarrays were expressed at higher levels than by the corresponding parenchymal cells. Thirteen of these genes were identified both in the lung and kidney screens from a subset of about 5000 genes. Many of these genes are known to be specifically expressed in endothelial cells, but about 200 genes were potentially novel endothelial genes. The preferential endothelial expression of a selected group of these genes was confirmed by quantitative polymerase chain reaction or in situ mRNA hybridization. Comparison of the genes expressed in lung and kidney endothelia revealed numerous differences. Notably, genes encoding components of an ephrin signaling pathway were highly expressed in lung endothelial cells. In summary, the genes we have identified represent potentially new pan-endothelial and tissue-specific endothelial markers.

Differential stimulation of cholesterol and unsaturated fatty acid biosynthesis in cells expressing individual nuclear sterol regulatory element-binding proteins

Three sterol regulatory element-binding proteins (SREBP-1a, -1c, and -2) stimulate transcription of genes involved in synthesis and receptor-mediated uptake of cholesterol and fatty acids. Here, we explore the individual roles of each SREBP by preparing lines of Chinese hamster ovary (CHO) cells that express graded amounts of nuclear forms of each SREBP (designated nSREBPs) under control of a muristerone-inducible nuclear receptor system. The parental hamster cell line (M19 cells) lacks its own nSREBPs, owing to a deletion in the gene encoding the Site-2 protease, which releases nSREBPs from cell membranes. By varying the concentration of muristerone, we obtained graded expression of individual nSREBPs in the range that restored lipid synthesis to near physiologic levels. The results show that nSREBP-2 produces a higher ratio of synthesis of cholesterol over fatty acids than does nSREBP-1a. This is due in part to a selective ability of low levels of nSREBP-2, but not nSREBP-1a, to activate the promoter for squalene synthase. nSREBP-1a and -2 both activate transcription of the genes encoding stearoyl-CoA desaturase-1 and -2, thereby markedly enhancing the production of monounsaturated fatty acids. nSREBP-1c was inactive in stimulating any transcription at the concentrations achieved in these studies. The current data support the emerging view that the nSREBPs act in complementary ways to modulate the lipid composition of cell membranes.

Purification and cDNA cloning of a second apoptosis-related cysteine protease that cleaves and activates sterol regulatory element binding proteins

We have purified from hamster liver a second cysteine protease that cleaves and activates sterol regulatory element binding proteins (SREBPs). cDNA cloning revealed that this enzyme is the hamster equivalent of Mch3, a human enzyme that is related to the interleukin 1beta converting enzyme. We call this enzyme Mch3/SCA-2. It is 54% identical to hamster CPP32/SCA-1, a cysteine protease that was earlier shown to cleave SREBPs at a conserved Asp between the basic helix-loop-helix leucine zipper domain and the membrane attachment domain. This cleavage liberates an NH2-terminal fragment of approximately 460 amino acids that activates transcription of genes encoding the low density lipoprotein receptor and enzymes of cholesterol synthesis. Mch3/SCA-2 and CPP32/SCA-I are synthesized as inactive 30-35 kDa precursors that are thought to be cleaved during apoptosis to generate active fragments of approximately 20 and approximately 10 kDa. The current data lend further support to the notion that SREBPs are cleaved and activated as part of the program in programmed cell death.

Purification of an interleukin-1 beta converting enzyme-related cysteine protease that cleaves sterol regulatory element-binding proteins between the leucine zipper and transmembrane domains

We describe the characterization and purification of a protease that cleaves sterol regulatory element-binding protein-1 (SREBP-1) and SREBP-2 in vitro. Cleavage occurs between the basic helix-loop-helix-leucine zipper and the first transmembrane domain of each SREBP. This is the region in which the SREBPs are cleaved physiologically by a sterol-regulated protease that releases an NH2-terminal fragment that activates transcription of the genes for the low density lipoprotein receptor and 3-hydroxy-3-methylglutaryl CoA synthase. The cleavage enzyme, designated SREBP cleavage activity (SCA), belongs to a new class of cysteine proteases of the interleukin-1 beta-converting enzyme (ICE) family, all of which cleave at aspartic acid residues. Like ICE, SCA was inactive in cytosol, and it was activated in vitro by incubation at 30 degrees C. SCA was resistant to inhibitors of serine, aspartyl, and metalloproteases, but it was sensitive to N-ethylmaleimide. The enzyme cleaved SREBP-1 and SREBP-2 between the Asp and Ser of a conserved sequence (S/DEPDSP). The activity was blocked by a tetrapeptide aldehyde, Ac-Asp-Glu-Ala-Asp-aldehyde (Ac-DEAD-CHO). A purified preparation of SCA from hamster liver contained a prominent 20-kDa polypeptide that could be labeled with [14C]iodoacetic acid. Labeling was blocked by Ac-DEAD-CHO. Partial amino acid sequence of this polypeptide revealed that it was the hamster equivalent of human CPP32, a putative protease whose cDNA was recently identified by virtue of sequence homology to ICE. CPP32 and ICE have been implicated in apoptosis in animal cells. Whether SCA/CPP32 participates in vivo in the sterol-regulated activation of SREBP, or whether it activates SREBPs during apoptosis, remains to be determined.

Absence of FMR-1 gene expression can be detected with RNA extracted from dried blood specimens

Fragile X syndrome is a genetic disorder caused by abnormal function of the FMR-1 gene. The majority of fragile X syndrome patients carry an expansion of the CGG tri-nucleotide repeat in the FMR-1 gene, whereas others have a deletion or a point mutation in the FMR-1 structural gene. In this report, we analyzed a typical family with three male patients. RNA from Epstein-Barr virus transformed lymphoblastoid cells was used for RNase protection assay and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Five normal individuals and one asymptomatic heterozygote from this family expressed detectable FMR-1 transcripts, whereas three fragile X patients showed no sign of expression with either assay. To extend the application of this PCR-based assay to laboratory diagnosis of fragile X syndrome, we confirmed that dried blood samples collected on screening filter papers for newborns are an adequate source of RNA for RT-PCR. Moreover, fragile X patients from the study family and another family were reliably identified by the absence of the FMR-1-specific PCR product from the dried blood specimens. Our studies indicate that this simple assay can be used to diagnose the fragile X syndrome for the majority of male patients.