Ker Y. Cheah
Boston Children's Hospital
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Featured researches published by Ker Y. Cheah.
Cancer Biology & Therapy | 2009
Ker Y. Cheah; Gordon S. Howarth; Roger Yazbeck; Tessa H. Wright; Eleanor J. Whitford; Caroline Payne; Ross N. Butler; Susan E.P. Bastian
Mucositis is a common side-effect of high-dose chemotherapy regimens. Grape seed extract (GSE) represents a rich source of proanthocyanidins with the potential to decrease oxidative damage and inflammation within the gastrointestinal tract. We evaluated GSE for its capacity to decrease the severity of chemotherapy-induced mucositis in vitro and in vivo. In vitro: GSE was administered to IEC-6 intestinal epithelial cells prior to damage induced by 5-Fluorouracil (5-FU). Cell viability was determined by neutral red assay. In vivo: Female Dark Agouti rats (130-180g) were gavaged with 1ml GSE (400mg/kg) daily (day 3-11) and received 5-FU (150mg/kg) by intraperitoneal (i.p.) injection on day 9 to induce mucositis. Rats were sacrificed at day 12 and intestinal tissues collected for myeloperoxidase and sucrase activity assays and histological analyses. Statistical analysis was performed by one-way ANOVA. GSE prevented the decrease in IEC-6 cell viability induced by 5-FU (p
Cancer Biology & Therapy | 2009
Tessa H. Wright; Roger Yazbeck; Kerry A. Lymn; Eleanor J. Whitford; Ker Y. Cheah; Ross N. Butler; Christine Feinle-Bisset; Amelia N. Pilichiewicz; Suzanne Mashtoub; Gordon S. Howarth
There is an acute need for the development of effective therapies for mucositis, a debilitating side effect of cancer chemotherapy. Iberogast® is a herbal extract reported to possess anti- inflammatory properties. We investigated Iberogast® for its potential to reduce the severity of 5-Fluorouracil (FU)-induced mucositis in rats. Rats were allocated to 3 treatment groups (n=8) and gavaged daily with a 10% solution of Iberogast® or water from day-0 to day-8. Rats were injected intraperitoneally with 5-FU (150mg/kg) or saline on day-6, and killed after 72hrs. In vivo and in vitro sucrase activity was assessed by 13C-sucrose breath test (SBT) and sucrase assay respectively. Intestinal disease severity was determined by histological assessment of villus height and crypt depth. Significant increases in villus height (277±9µm) and crypt depth (67±3µm) were observed in 5-FU+Iberogast®-treated rats compared with 5- FU+Water (224±13µm and 48±2µm respectively; p
Cancer Biology & Therapy | 2009
Eleanor J. Whitford; Adrian G. Cummins; Ross N. Butler; Luca D. Prisciandaro; Jane K. Fauser; Roger Yazbeck; Andrew J. Lawrence; Ker Y. Cheah; Tessa H. Wright; Kerry A. Lymn; Gordon S. Howarth
Beneficial bacteria (probiotics) and probiotic-derived factors have the potential to ameliorate disorders of the intestine. The aim of this study was to compare live Streptococcus thermophilus TH-4 (TH-4), dead TH-4 and TH-4 supernatant in rats treated with 5-Fluorouracil. Rats were randomly allocated to five treatment groups (n=8-10): Saline+Water; 5-FU+Skim Milk; 5-FU+Live TH-4; 5-FU+Supernatant TH-4; and 5-FU+Dead TH-4. 5-FU (150mg.kg-1) was administered by a single intraperitoneal injection on day 0; animals were killed on day 4. Treatments were administered daily from days -2 to 3 via oro-gastric gavage. Metabolic parameters were measured daily. Blood was obtained by cardiac puncture, and intestinal tissues removed for quantitative and qualitative histological assessment, including: villous height and area; crypt depth and area, mitotic count and crypt fission; biochemical determination of sucrase and myeloperoxidase (MPO) activity; and disease severity scoring. One-way ANOVA statistical analyses were conducted for the majority of outcome measures. Live TH-4 significantly reduced disease severity score by 13% (p
PLOS ONE | 2014
Ker Y. Cheah; Gordon S. Howarth; Keren A. Bindon; James A. Kennedy; Susan E.P. Bastian
Objective Grape seed procyanidins (PC) are flavan-3-ol oligomers and polymers known for their biological activity in the gut. Grape seed extract (GSE) have been reported to reduce intestinal injury in a rat model of mucositis. We sought to investigate effects of purified PC fractions differing in mean degree of polymerization (mDP) combined with 5-Fluorouracil (5-FU) chemotherapy on the viability of colon cancer cells (Caco-2). Design SixPC fractions (F1-F6) were isolated from Cabernet Sauvignon seeds at two ripeness stages: pre-veraison unripe (immature) and ripe (mature), utilizing step gradient, low-pressure chromatography on a Sephadex LH-20 resin. Fractions were tested on Caco-2 cells, alone and in combination with 5-FU. Eluted fractions were characterized by phloroglucinolysis and gel permeation chromatography. Cell viability was determined by the 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide) (MTT) assay. Results All isolated fractions significantly reduced Caco-2 cell viability compared to the control (P<0.05), but F2 and F3 (mDP 2–6) were the most active fractions (immature F2 = 32% mDP 2.4, F3 = 35% mDP 5.8 and mature F2 = 13% mDP 3.6 and F3 = 17% mDP 5.9; percentage of viable cells remaining) on Caco-2 cells. When combined with 5-FU, immature fractions F1-F3 enhanced the cell toxicity effects of 5-FU by 27–73% (P<0.05). Mature seed PC fractions (F1–F4) significantly enhanced the toxicity of 5-FU by 60–83% against Caco-2 cells (P<0.05). Moreover, some fractions alone were more potent at decreasing viability in Caco-2 cells (P<0.05; immature fractions = 65–68% and mature fractions = 83–87%) compared to 5-FU alone (37%). Conclusions PCs of mDP 2–6 (immature F1-F3 and mature F1 and F4)not only enhanced the impact of 5-FU in killing Caco-2 cells, but also surpassed standard 5-FU chemotherapy as an anti-cancer agent.The bioactivity of PC is therefore attributed primarily to lower molecular weight PCs.
Cancer Biology & Therapy | 2014
Hanru Wang; Susan E.P. Bastian; Ker Y. Cheah; Andrew J. Lawrence; Gordon S. Howarth
We evaluated the capacity for supernatants (SNs) derived from Escherichia coli Nissle 1917 (EcN), cultured under different growth conditions, to prevent 5-fluorouracil (5-FU)-induced intestinal epithelial cell damage. EcN was cultured in: Luria Bertani (LB) broth, tryptone soya broth (TSB), de Man Rogosa Sharpe (MRS) broth, and M17 broth supplemented with 10% (v/v) lactose solution (M17). Intestinal epithelial cells (IEC-6) were treated with the following EcN SNs: LB+, TSB+, MRS+, and M17+ in the presence and absence of 5-FU (1.5 or 5 μM). Cell viability, apoptotic activity and cell monolayer permeability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, and transepithelial electrical resistance (TER) assays, respectively. 5-FU significantly reduced cell viability (P < 0.05) at both 24 and 48 h. However, only EcN SN produced from LB and M17 growth media significantly decreased cell death induced by 5-FU (by approximately 10% after 24 and 48 h; and 10% after 24 h, respectively [P < 0.05]). When measured by flow cytometry all EcN SNs in the presence of 5-FU increased the proportion of viable cells (by 3–5% for 24 h, 3–7% for 48 h, P < 0.05) and reduced late-apoptotic cells after 24 and 48 h, compared with 5-FU control. Moreover, all EcN SNs significantly reduced the disruption of IEC-6 cell barrier function induced by 5-FU by 7–10% (P < 0.05), compared with DMEM control. We conclude that EcN derived factors could potentially reduce the severity of intestinal mucositis.
World Journal of Gastroenterology | 2016
Juliana E. Bajic; Georgina L Eden; Lorrinne S Lampton; Ker Y. Cheah; Kerry A. Lymn; Jinxin Pei; Andrea J. Yool; Gordon S. Howarth
AIM To investigate the effects of orally gavaged aqueous rhubarb extract (RE) on 5-fluorouracil (5-FU)-induced intestinal mucositis in rats. METHODS Female Dark Agouti rats (n = 8/group) were gavaged daily (1 mL) with water, high-dose RE (HDR; 200 mg/kg) or low-dose RE (LDR; 20mg/kg) for eight days. Intestinal mucositis was induced (day 5) with 5-FU (150 mg/kg) via intraperitoneal injection. Intestinal tissue samples were collected for myeloperoxidase (MPO) activity and histological examination. Xenopus oocytes expressing aquaporin 4 water channels were prepared to examine the effect of aqueous RE on cell volume, indicating a potential mechanism responsible for modulating net fluid absorption and secretion in the gastrointestinal tract. Statistical significance was assumed at P < 0.05 by one-way ANOVA. RESULTS Bodyweight was significantly reduced in rats administered 5-FU compared to healthy controls (P < 0.01). Rats administered 5-FU significantly increased intestinal MPO levels (≥ 307%; P < 0.001), compared to healthy controls. However, LDR attenuated this effect in 5-FU treated rats, significantly decreasing ileal MPO activity (by 45%; P < 0.05), as compared to 5-FU controls. 5-FU significantly reduced intestinal mucosal thickness (by ≥ 29% P < 0.001) as compared to healthy controls. LDR significantly increased ileal mucosal thickness in 5-FU treated rats (19%; P < 0.05) relative to 5-FU controls. In xenopus oocytes expressing AQP4 water channels, RE selectively blocked water influx into the cell, induced by a decrease in external osmotic pressure. As water efflux was unaltered by the presence of extracellular RE, the directional flow of water across the epithelial barrier, in the presence of extracellular RE, indicated that RE may alleviate water loss across the epithelial barrier and promote intestinal health in chemotherapy-induced intestinal mucositis. CONCLUSION In summary, low dose RE improves selected parameters of mucosal integrity and reduces ileal inflammation, manifesting from 5-FU-induced intestinal mucositis.
Nutrition and Cancer | 2016
Suzanne Mashtoub; Lorrinne S Lampton; Georgina L Eden; Ker Y. Cheah; Kerry A. Lymn; Juliana E. Bajic; Gordon S. Howarth
ABSTRACT Chemotherapy-induced mucositis is characterized by inflammation and ulcerating lesions lining the alimentary tract. Emu Oil and Lyprinol™ have independently demonstrated their therapeutic potential in intestinal inflammatory disorders, including mucositis. We investigated Emu Oil and Lyprinol™ in combination for their further potential to alleviate chemotherapy-induced mucositis in rats. Rats were gavaged with (1 ml) water, Olive Oil, Emu Oil + Olive Oil, Lyprinol™ + Olive Oil or Emu Oil + Lyprinol™ from Days 0 to 7, injected with saline (control) or 5-Fluorouracil (5-FU) on Day 5 and euthanized on Day 8. Myeloperoxidase (MPO) activity (indicative of acute inflammation), histological severity scores, and intestinal architecture were quantified. Myeloperoxidase activity was significantly increased in the jejunum and ileum following 5-FU, compared to saline controls. Both Olive Oil and Emu Oil + Lyprinol™ significantly reduced jejunal MPO levels (1.8-fold and 1.7-fold, respectively), whereas only Emu Oil + Lyprinol™ significantly decreased ileal MPO levels, relative to 5-FU controls. All oil treatments decreased histological severity scores in the jejunum and ileum, and normalized crypt depth in the mid small intestine, relative to 5-FU controls. Emu Oil combined with Lyprinol™ partially reduced acute small intestinal inflammation. Isolating bioactive constituents of these naturally sourced oils could provide a more targeted strategy to protect against intestinal mucositis.
Gastroenterology | 2014
Ker Y. Cheah; Gordon S. Howarth; Keren A. Bindon; James A. Kennedy; Suzanne Mashtoub; Susan E.P. Bastian
ESR2 physical interactions. Surprisingly, our preliminary results showed an upregulation in EGFR signals in ERB041 treated ESR2 transfectants. Summary: In AA with adenomas, reductions in ESR2 expression might contribute to higher colon cancer incidence and worse prognosis. The in vitro studies confirmed that ESR2 suppresses colon cancer cell proliferation. We postulate that the antiproliferative effects of ESR2 involve miR-145 dependent, EGFRindependent pathways. Our study suggests that ESR2 down-regulation might play an important role in colon cancer risk and contribute to racial differences in cancer progression.
Experimental Biology and Medicine | 2018
Suzanne Mashtoub; Ker Y. Cheah; Kerry A. Lymn; Gordon S. Howarth
Previously, we reported that orally administered Emu Oil (EO) increases mucosal thickness in the small intestine and colon in rodent models of chemotherapy-induced mucositis and colitis. However, it remains unclear whether mucosal thickening (crypt and villus lengthening) represents a process of normal or aberrant growth. We sought to determine if villus height (VH) and crypt depth (CD) measurements returned to normal in EO-treated rats following withdrawal of EO therapy. Dark agouti rats (n = 8/group) were gavaged daily for 10 days with water, olive oil (OO), or EO (0.5 mL or 1 mL). Groups of rats were euthanized on days 10 and 17. Intestinal weights, lengths, VH, and CD were quantified. P < 0.05 was considered significant. On day 10, jejuno–ileum weight was increased by OO (26%) and EO (0.5 mL: 15%; 1 mL: 29%) compared to water controls (P < 0.01), which was normalized by day 17. On days 10 and 17, jejuno-ileum length was greater in OO- (12%) and EO-treated rats (0.5 mL: 8%; 1 mL: 12%; P < 0.05), relative to water controls. On day 10, OO and EO increased ileal VH (OO: 32%; 0.5 EO: 22%; EO: 35%; P < 0.01) and CD (OO: 17%; 0.5 EO: 13%; EO: 22%) compared to water controls. Importantly, however, after withdrawal of all oils, VH and CD measurements returned to normal control values. Moreover, the VH:CD ratio (potential indicator of dysplasia) remained unchanged in all experimental groups on days 10 and 17. The restoration of normal intestinal architecture following cessation of Emu Oil therapy supports its safety for application in intestinal disorders. Impact statement Uncontrolled inflammation and intestinal proliferation can predispose to the development of colorectal cancer. In previous pre-clinical studies, we demonstrated that oral administration of Emu Oil promotes intestinal repair via stimulation of the mucosa in response to tissue injury and inflammation. Therefore, it was important to determine if Emu Oil administration did not promote the precocious development of colorectal cancer. The current study revealed that Emu Oil returned indicators of intestinal proliferation back to normal values after a period of seven days. These data strongly support the safety of Emu Oil for further studies in the context of bowel inflammation.
Archive | 2011
Ker Y. Cheah; Gordon S. Howarth; Susan E.P. Bastian
Aims To compare the incidence of gastrostomy complications with a primary gastrostomy versus gastrostomy with concurrent fundoplication and neurologically impaired versus neurologically normal children. Additionally two low profi le devices (LPD) one with balloon retention the other with silicone bolster retention were compared for their longevity. Methods Ninety eight patients (58 males, mean age 4.66 years) with 107 gastrostomies inserted between April 2004 and May 2008 were included in this retrospective, single institution audit. Follow up data was obtained up to June 2009, enabling a minimum follow up period of one year. The specifi c complications reviewed were tube related (malinsertion and malposition post LPD placement), site related (wound infection/breakdown confi rmed with swab, hypergranulation requiring treatment and skin excoriation requiring dressings). Logistic regression analysis was used with a statistical signifi cance defi ned as p value < 0.05. Results There were 63 primary gastrostomies and 44 with concurrent fundoplication, 71 children were neurologically impaired and 36 were neurologically normal. The mean follow up time was 35.6 ± 1.41 months. There were 4 malinsertions and 5 malpositions post low profi le device insertion with no association between primary gastrostomy and concurrent fundoplication or neurological status. While hypergranulation was a problem with 71–91% in all groups there was no statistical signifi cance between the groups. The odds of an infection with gastrostomy plus concurrent fundoplication are 2.38 times greater than for gastrostomy alone (95% CI, 1.02, 5.56; p = 0.02). The odds of excoriation are 2.50 times greater in patients receiving gastrostomy plus concurrent fundoplication than for gastrostomy alone (95% CI 1.09–5.71; p = 0.015). There was no statistical association with neurological impaired or neurological normal children. Low profi le device replacement rates were signifi cantly higher for those with balloon retention (1.77 per year) compared with silicone bolster retention (0.56 per year). Conclusion There is a higher incidence of site infection and skin excoriation for gastrostomy placement with concurrent fundoplication. There was no signifi cant difference between neurologically impaired compared with neurologically normal children. Low profi le balloon devices were changed three times more often than those with silicone bolster retention.