FLLL12 induces apoptosis in lung cancer cells through a p53/p73-independent but death receptor 5-dependent pathway

Unlike chemotherapy drugs, the safety of natural compounds such as curcumin has been well established. However, the potential use of curcumin in cancer has been compromised by its low bioavailability, limited tissue distribution and rapid biotransformation leading to low in vivo efficacy. To circumvent these problems, more potent and bioavailable analogs have been synthesized. In the current study, we investigated the mechanism of anti-tumor effect of one such analog, FLLL12, in lung cancers. IC50 values measured by sulforhodamine B (SRB) assay at 72 h and apoptosis assays (annexin V staining, cleavage of PARP and caspase-3) suggest that FLLL12 is 5-10-fold more potent than curcumin against a panel of premalignant and malignant lung cancer cell lines, depending on the cell line. Moreover, FLLL12 induced the expression of death receptor-5 (DR5). Ablation of the expression of the components of the extrinsic apoptotic pathway (DR5, caspase-8 and Bid) by siRNA significantly protected cells from FLLL12-induced apoptosis (p < 0.05). Analysis of mRNA expression revealed that FLLL-12 had no significant effect on the expression of DR5 mRNA expression. Interestingly, inhibition of global phosphatase activity as well as protein tyrosine phosphatases (PTPs), but not of alkaline phosphatases, strongly inhibited DR5 expression and significantly inhibited apoptosis (p < 0.05), suggesting the involvement of PTPs in the regulation of DR5 expression and apoptosis. We further showed that the apoptosis is independent of p53 and p73. Taken together, our results strongly suggest that FLLL12 induces apoptosis of lung cancer cell lines by posttranscriptional regulation of DR5 through activation of protein tyrosine phosphatase(s).

Is malnutrition a risk factor of stroke?

Obesity is an established risk factor of stroke. Malnutrition in post-stroke period is common and can influence outcome. But malnutrition, though predicted, has not yet been established as a risk factor of stroke. This descriptive study was carried out in the Department of Neurology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka and Department of Neurology, Dhaka Medical College (DMC), from January 2009 to December 2010 to explore whether malnutrition is an independent risk factor of stroke. Nutritional status of 100 stroke patients and 100 healthy controls were assessed in this study. Anthropometric measurements including Body Mass Index (BMI), Triceps skin fold (TSF), Mid-arm circumference (MAC) and Arm-muscle circumference (AMC) were measured within 7 days of stroke. Haemoglobin and haematocrit percentage, serum iron and serum albumin were measured at the same time. No significant difference was observed regarding TSF thickness, MAC, AMC, mean Hb and mean albumin level between the stroke patients and the control group, although iron level was significantly lower in stroke group. Multiple logistic regressions analysis showed that increase in age, smoking and decreased serum iron level has a positive association with stroke. Malnutrition is, according to this study, not a significant risk factor of stroke and triceps skin fold (TSF) thickness, mid-arm circumference (MAC), arm-muscle circumference (AMC), hemoglobin and serum albumin are not appropriate predictor of stroke.

Abstract 2269: Combination of erlotinib and epigallocatechin-3-gallate induces apoptosis of squamous cell carcinoma of the head and neck through posttranslational regulation of Bim and Bcl-2

Purpose: Effective chemopreventive strategies could save millions of lives. We have previously reported that the combination of the EGFR-TKI erlotinib and the green tea constituent epigallocatechin-3-gallate (EGCG) exhibited synergistic chemopreventive effects in head and neck cancers by inducing the expression of Bim, p21, p27, and inhibiting the phosphorylation of ERK and AKT and expression of Bcl-2. In the current study, we further investigated the mechanism of regulation of Bim, Bcl-2, p21 and p27, and their role in apoptosis.

Methods: Well characterized and genetically validated squamous cell carcinoma of the head and neck cell lines were used throughout the study. Annexin V staining was conducted for apoptosis assay. Expression of mRNAs and proteins were measured by RT-PCR and Western blotting, respectively. Gene overexpression and knockdown strategies were used to activate or shut down the expression of specific proteins.

Results: siRNA-mediated silencing of Bim significantly inhibited apoptosis induced by the combination of erlotinib and EGCG (p=). On the other hand, overexpression of Bcl-2 significantly protected cells from apoptosis (p=), whereas overexpression of constitutively AKT had minimal effect on apoptosis (actual values). Analysis of mRNA expression by RT-PCR revealed that neither erlotinib, EGCG nor their combination had any significant effects on the mRNA expression of Bim, p21, p27 or Bcl-2, suggesting post-transcriptional regulation of Bim, p21, p27 and Bcl-2 by the combination of erlotinib and EGCG. Furthermore, we found that erlotinib or the combination of EGCG and erlotinib inhibited the phosphorylation of Bim, and that inhibition of protein translation by cycloheximide pretreatment stabilized Bim, suggesting posttranslational regulation of Bim.

Conclusion: Our results strongly suggest that the combination of erlotinib and EGCG induces apoptosis of SCCHN cells by regulating Bim and Bcl-2 at the post-translational level. Currently, a clinical trial is underway at Winship Cancer Institute of Emory University to inhibit or reverse the progression of oral premalignant lesions using this combination. (This study is supported by R03CA159369, P50CA128613 and Robbins Scholar Award of Winship Cancer Institute).

Citation Format: Abedul Haque, Mohammad A. Rahman, Zhuo G. Chen, Dong M. Shin, A.R.M. Ruhul Amin. Combination of erlotinib and epigallocatechin-3-gallate induces apoptosis of squamous cell carcinoma of the head and neck through posttranslational regulation of Bim and Bcl-2. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2269. doi:10.1158/1538-7445.AM2014-2269

An additional strip of mesh minimizes hernia recurrence after laparoscopic totally extraperitoneal (TEP) inguinal hernia repair. An analysis of 490 cases over 10 years

AIM

The laparoscopic inguinal hernia repair has gained significant interest over the years as an alternative to the conventional open technique as a result of its faster recovery time, reduced postoperative pain and numbness. However the recurrence rates are in the order of 2.3% compared to the 1.3% quoted for the equivalent open approach. Much of these recurrences occur either caudal to the fold created in the mesh once in-situ or lateral to the border of the mesh. This technique aims to address both these areas of concern using an additional strip of mesh across the centre to brace the mesh and create a bolster to maintain mesh stability.

METHODS

The technique involves cutting a 2 cm strip from the 15x15 cm mesh which is laid length-ways over the remaining 13x15 cm mesh, keeping the longest dimension in the medial to lateral plane, and loosely tacked. The strip over hangs the lateral border of the mesh to control the lateral space. Recurrence rates were evaluated from a prospectively collected data series as well as outcomes collected from a questionnaire over a 10 year period between January 2001 and October 2011. Primary outcomes were confirmed hernia recurrence requiring surgical repair.

RESULTS

Four hundred ninety-one patients underwent laparoscopic totally extraperitoneal (TEP) hernia repair with outcomes including recurrence rates were retrospectively examined through a prospectively collected database. Subsequently 400 patients were sent a validated questionnaire. 246 responded (62% response rate). One recurrence (0.3%), which occurred 4 years after the original laparoscopic repair, was described across the series.

CONCLUSION

The use of the additional mesh strip potentially reduces TEP hernia recurrence rates beyond simply the benefits of the learning curve. Although, questionnaires are notoriously inaccurate, the value and consistency between both evaluation techniques suggests that this level of reduction is significant to warrant further prospective trials.

Abstract 2283: Potent curcumin analog FLLL-12 targets both intrinsic and extrinsic signaling pathways to induce apoptosis in lung cancers

Background: Curcumin is the major bioactive compound isolated from the rhizome of Curcuma longa (turmeric). Despite its high margin of safety and efficacy against various types of cancers, the potential utility of curcumin as a chemopreventive/chemotherapeutic drug is compromised by its low bioavailability and poor selectivity. To circumvent these problems, more potent and selective curcumin analogues have been developed. In the current study, we investigated the mechanism of apoptosis of one such synthetic analogue, FLLL-12, against lung cancers. This compound was reported to exhibit potent anti-tumor activity against prostate, colon and breast cancer cell lines. However, its mechanism of growth inhibition has yet to be elucidated.

Methods: Multiple premalignant and fully transformed lung cancer cell lines were used throughout the study. SRB assay was used to measure cell growth inhibition. Annexin V staining was conducted for apoptosis assay. Expression of mRNAs and proteins were measured by RT-PCR and Western blotting, respectively. Gene overexpression and knockdown strategies were used to activate or shut down of specific proteins.

Results: IC50 values and apoptosis assay results showed that FLLL-12 was ∼10-fold more potent than the natural parent compound, curcumin, against lung cancer cells. Further mechanistic studies revealed that FLLL-12 induced the expression of DR5, inhibited the protein expression of EGFR, p-AKT, AKT and Bcl-2 and increased the expression of BIM. Analysis of mRNA expression suggested that FLLL-12 strongly inhibited the mRNA expression of EGFR and AKT, whereas the expression of Bcl-2 and Bim mRNAs remained unchanged. FLLL-12 also induced the expression of p53 and p73. However, inactivation of these proteins with their dominant negative construct or siRNA had no significant effects on apoptosis induction.

Conclusions: Our results strongly suggest that FLLL-12 is a potent curcumin analog that induces apoptosis of lung cancer cell lines by targeting: (1) intrinsic pathways via transcriptional inhibition of EGFR and AKT and induction of BIM, and (2) extrinsic pathway via induction of DR5. Future in vivo studies using appropriate animal models are warranted for further development of this promising compound for cancer prevention and/or treatment for lung cancer.

(Supported by R03CA171663, P50CA128613 and Robbins Scholar Award of Winship Cancer Institute of Emory University).

Citation Format: A.R.M. Ruhul Amin, Abedul Haque, Mohammad A. Rahman, James R. Fuchs, Zhuo G. Chen, Dong M. Shin. Potent curcumin analog FLLL-12 targets both intrinsic and extrinsic signaling pathways to induce apoptosis in lung cancers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2283. doi:10.1158/1538-7445.AM2014-2283

Lipopolysaccharide impairs insulin sensitivity via activation of phosphoinositide 3-kinase in adipocytes

The effect of lipopolysaccharide (LPS) on insulin sensitivity in adipocytes were examined by using differentiated 3T3-L1 adipocytes. Insulin-mediated activation of insulin receptor substrate (IRS) 1/2 was inhibited in LPS-pretreated adipocytes and IRS1/2-mediated Akt activation was also attenuated in those cells. LPS inhibited activation of glycogen synthase kinase 3 as a negative regulator of glycogenesis and impaired the glycogen synthesis in response to insulin. LPS-induced activation of phosphoinositide 3-kinase (PI3K) in adipocytes. Involvement of suppressor of cytokine signaling 3 (SOCS3) in LPS-induced IRS1/2 inhibition was excluded. Considering that both insulin and LPS were able to activate the PI3K/Akt signaling pathway, LPS was suggested to impair insulin sensitivity of adipocytes through down-regulating insulin-mediated PI3K/Akt activation.

Does folic acid supplementation rescue defects in ECE-1-deficient mouse embryos?

Endothelin (ET) signalling is essential for normal embryonic development. Disruption of this pathway leads to defects in the development of subsets of cranial and cephalic neural crest derivatives. Endothelin-converting enzyme 1 (ECE-1) is a ratelimiting step in the biosynthesis of ET-1. Recently, there has been considerable interest in the protective role of folic acid (FA) against congenital anomalies via increasing the expression of ET-1. We have tested whether FA supplementation can rescue craniofacial and cardiac defects observed in the ECE1-/- embryos. ECE1+/- mice were caged together to obtain litters containing embryos of all possible genotypes. The treatment group had the diet supplemented with 20 mg/kg of FA from the day of discovery of the vaginal plug. FA supplementation did not result in modified proportions of the genotypes, indicating no rescue of the embryonic mortality. There was also no effect on the litter size. Craniofacial and cardiac defects were likewise identical in the ECE1-/- embryos of both groups. There was a mild but significant reduction in the embryo size in wild-type and heterozygous FA-supplemented embryos, and there were haemorrhages in the wild-type supplemented embryos at ED14.5. Expression of ET receptor A detected by immunohistochemistry was up-regulated in the ECE1-/- embryos, but FA supplementation had no effects on the distribution of staining intensity. We conclude that FA is not able to rescue the phenotype in this model, suggesting an alternative pathway for its action. These results also caution against indiscriminate use of dietary supplements in attempts to prevent congenital anomalies.

Occurrence of virulence genes, 16S rRNA methylases, and plasmid-mediated quinolone resistance genes in CTX-M-producing Escherichia coli from Pakistan

The aim of the study was to conduct a comprehensive molecular characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli collected from Pakistan. Genetic relatedness among 98 ESBL-producing E. coli was measured by pulsed-field gel electrophoresis (PFGE). The presence of genes encoding ESBLs, virulence factors (VFs), 16S rRNA methylases, plasmid-mediated quinolone resistance (PMQR) encoding elements, plasmid replicon types, phylogenetic groups of E. coli, prevalence of the worldwide disseminated clone E. coli ST131, and phylogrouping of CTX-M enzymes was investigated by polymerase chain reaction (PCR). All isolates carried bla CTX-M genes and, except for one isolate from CTX-M phylogroup 9, they all belonged to CTX-M phylogroup 1. The isolates were genetically diverse with PFGE. Phylogenetic group D (36 %) was most abundant in this collection of E. coli, whereas isolates belonging to B2 (22 %) had the highest content of virulence genes. PMQR genes were found in 84.6 % of the isolates; among them, 93 % isolates were positive for variants of acetyltransferases (aac(6')-lb-cr), whereas qnrB, qepA, and qnrS were present in 11 %, 5 %, and 4 % of the isolates, respectively. Only 3 % of the isolates contained genes encoding 16S rRNA methylases. The most abundant replicon type was IncF (96 %), and 18 % of the isolates belonged to the ST131 clone. Out of 34 investigated VFs, 24 genes encoding different types of adhesins, protectins, toxins, siderophores, and other VFs were found. Although the isolates in this collection were highly resistant to many antimicrobials, susceptibility to amikacin and meropenem was retained.

What liver transplant outcomes can be expected in the uninsured who become insured via the Affordable Care Act?

Our study objective is to measure the survival impact of insurance status following liver transplantation in a cohort of uninsured "charity care" patients. These patients are analogous to the population who will gain insurance via the Affordable Care Act. We hypothesize there will be reduced survival in charity care compared to other insurance strata. We conducted a retrospective study of 898 liver transplants from 2000 to 2010. Insurance cohorts were classified as private (n = 640), public (n = 233) and charity care (n = 23). The 1, 3 and 5-year survival was 92%, 88% and 83% in private insurance, 89%, 80% and 73% in public insurance and 83%, 72% and 51% in charity care. Compared to private insurance, multivariable regression analyses demonstrated charity care (HR 3.11, CI 1.41-6.86) and public insurance (HR 1.58, CI 1.06-2.34) had a higher 5-year mortality hazard ratio. In contrast, other measures of socioeconomic status were not significantly associated with increased mortality. The charity care cohort demonstrated the highest incidence of acute rejection and missed clinic appointments. These data suggest factors other than demographic and socioeconomic may be associated with increased mortality. Further investigations are necessary to determine causative predictors of increased mortality in liver transplant patients without private insurance.

Lipopolysaccharide prevents valproic acid-induced apoptosis via activation of nuclear factor-κB and inhibition of p53 activation

The effect of lipopolysaccharide (LPS) on valproic acid (VPA)-induced cell death was examined by using mouse RAW 264.7 macrophage cells. LPS inhibited the activation of caspase 3 and poly (ADP-ribose) polymerase and prevented VPA-induced apoptosis. LPS inhibited VPA-induced p53 activation and pifithrin-α as a p53 inhibitor as well as LPS prevented VPA-induced apoptosis. LPS abolished the increase of Bax/Bcl-2 ratio, which is a critical indicator of p53-mediated mitochondrial damage, in response to VPA. The nuclear factor (NF)-κB inhibitors, Bay 11-7082 and parthenolide, abolished the preventive action of LPS on VPA-induced apoptosis. A series of toll-like receptor ligands, Pam3CSK4, poly I:C, and CpG DNA as well as LPS prevented VPA-induced apoptosis. Taken together, LPS was suggested to prevent VPA-induced apoptosis via activation of anti-apoptotic NF-κB and inhibition of pro-apoptotic p53 activation. The detailed inhibitory mechanism of VPA-induced apoptosis by LPS is discussed.

Mouse pyrin and HIN domain family member 1 (pyhin1) protein positively regulates LPS-induced IFN-β and NO production in macrophages

The pyrin and HIN-domain (PYHIN) family member1 (pyhin1) is a member of PYHIN proteins and involved in transcriptional regulation of genes important for cell cycle control, differentiation and apoptosis. The regulatory action of mouse pyhin1 on LPS-induced inflammatory response was examined. LPS augmented the pyhin1 mRNA expression in murine RAW 264.7 macrophage cells and peritoneal macrophages. The augmentation of pyhin1 mRNA expression was abolished by parthenolide, a NF-κB inhibitor. Silencing of pyhin1 with small interfering RNA reduced the production of IFN‐β and NO. However, pyhin1 silencing did not affect the production of TNF-α, IL-6, IL-10 and prostaglandin E2. Reduced IFN-β production by pyhin1 silencing caused inactivation of STAT1 and reduced expression of IRF1. Pyhin1 silencing inhibited the expression of TRAF6, TBK1 and TRIF, which trigger IFN-β production in the MyD88-independent pathway. However, pyhin1 silencing did not affect the expression of MyD88, IRAK4 and several mitogen-activated protein kinases in the MyD88-dependent pathway. Taken together, mouse pyhin1 was suggested to be a NF-κB-responsible gene in response to LPS and positively regulate LPS-induced IFN-β and NO production through up-regulating the MyD88-independent signaling pathway.

Pattern of cutaneous tuberculosis among children and adolescent

Cutaneous tuberculosis is one of the most subtle and difficult diagnoses for dermatologists practicing in developing countries. It has widely varied manifestations and it is important to know the spectrum of manifestations in children and adolescent. Sixty cases (age<19 years) of cutaneous tuberculosis were included in this one period study. The diagnosis was based on clinical examination, tuberculin reaction, histopathology, and response to antitubercular therapy. Histopahology revealed 38.3% had skin tuberculosis and 61.7% had diseases other than tuberculosis. Among 23 histopathologically proved cutaneous tuberculosis, 47.8% had scrofuloderma, 34.8% had lupus vulgaris and 17.4% had tuberculosis verrucosa cutis (TVC). Most common site for scrofuloderma lesions was neck and that for lupus vulgaris and TVC was lower limb. Cutaneous tuberculosis in children continues to be an important cause of morbidity, there is a high likelihood of internal involvement, especially in patients with scrofuloderma. A search is required for more sensitive, economic diagnostic tools. DOI: http://dx.doi.org/10.3329/bmrcb.v38i3.14335 Bangladesh Med Res Counc Bull 2012; 38(3): 94-97 (December)

An Uncommon Ventricular Tachycardia due to Inactive PPM Lead

Our patient had recurrent syncope due to ventricular tachycardia (VT) after one year of VVI Pacemaker implantation. He had pacemaker pocket infection for which new pacemaker was implanted on opposite side but old lead was not explanted completely. Flouroscopy showed redundant loop of old lead in right ventricular inflow which was snared out subsequently. He never had syncope or VT after that.

Comparative study of total prostate specific antigen and free to total prostate specific antigen ratio in the diagnosis of prostate cancer

This descriptive study was done to compare total Prostate Specific Antigen (tPSA) and the Free to Total Prostate Specific Antigen [(F/T) PSA] ratio measurements for prostate cancer detection. This study included a total of 43 patients with suspected prostate cancer observed over a period of 12 months. Out of 43 consecutive male patients (mean age 69±9.39 years, range 48-100 years), 32 had benign disease (74%) and 11 had prostate carcinoma patients (26%), who had histologically proven prostate cancer. The mean total PSA was 67.9 ng/ml and 12.4 ng/ml in patients with carcinoma prostate and nodular hyperplasia of prostate (NHP) respectively (p<0.05). The mean free PSA in carcinoma patients was 7.4±9.8 ng/ml and in NHP patients it was 2.3±4.1 ng/ml. The difference in mean free PSA concentration was significant (p<0.05). The free to total PSA ratio in two groups was significantly different (p<0.01) from each other. In carcinoma patients, mean F/T PSA ratio was 0.144±0.152 as compared 0.328±0.076 in patients with benign disease. The sensitivity and specificity of the test was calculated at different F/T PSA ratio cutoff. At 0.1 cut off value, sensitivity of the test was 64% and specificity was 84%. The positive predictive value (PPV) was 58% and negative predictive value (NPV) was 87%. From cutoff value of 0.12 to 0.16, sensitivity was increased from 64% to 91% but specificity was reduced from 84% to 59%. The PPV did not show much change and NPV was increased from 89% to 95%. Increasing the cut off value thereafter showed no change in sensitivity but specificity was further reduced to 41%. Therefore in this patient, F/T PSA ratio cut off of 0.15 was found to be the appropriate cutoff value. In 43 men who were biopsied, 11(26%) prostatic carcinoma were identified. Only one patient (9.1%) had F/T PSA ratio above 0.15 and diagnosed by biopsied. Out of 32 patients who were negative for malignancy, 13 patients had F/T PSA ratio more than 0.15 and 19 patients had F/T PSA ratio less than 0.15. The validity of tPSA and F/T PSA ratio in the diagnosis of prostate cancer was identified by calculating their sensitivity, specificity, PPV and NPV. In case of F/T PSA ratio the sensitivity was 91% and in conventional tPSA the sensitivity was 82%. Specificity was low in both the cases. But in tPSA the specificity was only 13% compare to 59% in F/T PSA. Positive predictive value (PPV) for tPSA was 25% and in F/T PSA it was 44%. Negative predictive value (NPV) for t PSA was 67% and for F/T PSA was 95% which was very high. The effectiveness of F/T PSA ratio at 0.15 cut off value with corresponding tPSA>10ng/ml shows sensitivity 83% in prostate cancer and 50% in NHP patient.