A Ketogenic Diet in Combination with Gemcitabine Mitigates Pancreatic Cancer-Associated Cachexia in Male and Female KPC Mice.

Cancer-associated cachexia (CAC) is a critical contributor to pancreatic ductal adenocarcinoma (PDAC) mortality. Thus, there is an urgent need for new strategies to mitigate PDAC-associated cachexia; and the exploration of dietary interventions is a critical component. We previously observed that a ketogenic diet (KD) combined with gemcitabine enhances overall survival in the autochthonous LSL-KrasG12D/+; LSL-Trp53 R172H/+; Pdx1-Cre (KPC) mouse model. In this study, we investigated the effect and cellular mechanisms of a KD in combination with gemcitabine on the maintenance of skeletal muscle mass in KPC mice. For this purpose, male and female pancreatic tumor-bearing KPC mice were allocated to a control diet (CD), a KD, a CD + gemcitabine (CG), or a KD + gemcitabine (KG) group. We observed that a KD or a KG-mitigated muscle strength declined over time and presented higher gastrocnemius weights compared CD-fed mice. Mechanistically, we observed sex-dependent effects of KG treatment, including the inhibition of autophagy, and increased phosphorylation levels of eIF2α in KG-treated KPC mice when compared to CG-treated mice. Our data suggest that a KG results in preservation of skeletal muscle mass. Additional research is warranted to explore whether this diet-treatment combination can be clinically effective in combating CAC in PDAC patients.

Phospho-valproic acid (MDC-1112) reduces pancreatic cancer growth in patient-derived tumor xenografts and KPC mice: enhanced efficacy when combined with gemcitabine.

New chemotherapeutic agents are needed for pancreatic cancer (PC). We have previously shown that phospho-valproic acid (MDC-1112) is effective in cell-line xenografts of PC. Here, we explored whether MDC-1112 is effective in additional clinically relevant animal models of PC and whether MDC-1112 enhances the anticancer effect of clinically used chemotherapeutic agents. MDC-1112 alone strongly reduced patient-derived pancreatic tumor xenograft growth, and extended survival of LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) mice. In both models, MDC-1112 inhibited STAT3 activation and its downstream signals, including Bcl-xL and cyclin D1. In human PC cell lines, P-V enhanced the growth inhibitory effect of gemcitabine (GEM), Abraxane and 5-FU, but not that of irinotecan. Normal human pancreatic epithelial cells were more resistant to the cytotoxic effects of MDC-1112/GEM combination. Furthermore, MDC-1112 enhanced GEM's effect on colony formation, apoptosis, cell migration, and cell invasion. In vivo, MDC-1112 and GEM, given alone, reduced patient-derived pancreatic tumor xenograft growth by 58% and 87%, respectively; whereas MDC-1112/GEM combination reduced tumor growth by 94%, inducing tumor stasis. In conclusion, MDC-1112 should be further explored as a potential agent to be used in combination with GEM for treating PC.

EGCG sensitizes chemotherapeutic-induced cytotoxicity by targeting the ERK pathway in multiple cancer cell lines.

Epigallocatechin-3-gallate (EGCG), a major polyphenol component of green tea, presents anticancer efficacy. However, its exact mechanism of action is not known. In this study, we evaluated the effect of EGCG alone or in combination with current chemotherapeutics [gemcitabine, 5-flourouracil (5-FU), and doxorubicin] on pancreatic, colon, and lung cancer cell growth, as well as the mechanisms involved in the combined action. EGCG reduced pancreatic, colon, and lung cancer cell growth in a concentration and time-dependent manner. EGCG strongly induced apoptosis and blocked cell cycle progression. Moreover, EGCG enhanced the growth inhibitory effect of 5-FU and doxorubicin. Of note, EGCG enhanced 5-FU's and doxorubicin's effect on apoptosis, but not on cell cycle. Mechanistically, EGCG reduced ERK phosphorylation concentration-dependently, and sensitized gemcitabine, 5-FU, and doxorubicin to further suppress ERK phosphorylation in multiple cancer cell lines. In conclusion, EGCG presents a strong anticancer effect in pancreatic, colon, and lung cancer cells and is a robust combination partner for multiple chemotherapeutics as evidenced by reducing cancer cell growth, in part, by inhibiting the ERK pathway.

Phospho-valproic acid (MDC-1112) suppresses glioblastoma growth in preclinical models through the inhibition of STAT3 phosphorylation.

New therapeutic strategies against glioblastoma multiforme (GBM) are urgently needed. Signal transducer and activator of transcription 3 (STAT3), constitutively active in many GBM tumors, plays a major role in GBM tumor growth and represents a potential therapeutic target. We have documented previously that phospho-valproic acid (MDC-1112), which inhibits STAT3 activation, possesses strong anticancer properties in multiple cancer types. In this study, we explored the anticancer efficacy of MDC-1112 in preclinical models of GBM, and evaluated its mode of action. MDC-1112 inhibited the growth of multiple human GBM cell lines in a concentration- and time-dependent manner. Normal human astrocytes were resistant to MDC-1112, indicating selectivity. In vivo, MDC-1112 reduced the growth of subcutaneous GBM xenografts in mice by up to 78.2% (P < 0.01), compared with the controls. Moreover, MDC-1112 extended survival in an intracranial xenograft model. Although all vehicle-treated mice died by 19 days of treatment, 7 of 11 MDC-1112-treated mice were alive and healthy by the end of 5 weeks, with many showing tumor regression. Mechanistically, MDC-1112 inhibited STAT3 phosphorylation at the serine 727 residue, but not at tyrosine 705, in vitro and in vivo. STAT3 overexpression rescued GBM cells from the cell growth inhibition by MDC-1112. In addition, MDC-1112 reduced STAT3 levels in the mitochondria and enhanced mitochondrial levels of reactive oxygen species, which triggered apoptosis. In conclusion, MDC-1112 displays strong efficacy in preclinical models of GBM, with the serine 727 residue of STAT3 being its key molecular target. MDC-1112 merits further evaluation as a drug candidate for GBM. New therapeutic options are needed for glioblastoma. The novel agent MDC-1112 is an effective anticancer agent in multiple animal models of glioblastoma, and its mechanism of action involves the inhibition of STAT3 phosphorylation, primarily at its Serine 727 residue.

A novel tricarbonylmethane agent (CMC2.24) reduces human pancreatic tumor growth in mice by targeting Ras.

Pancreatic Cancer (PC) is a deadly disease in need of new therapeutic options. We recently developed a novel tricarbonylmethane agent (CMC2.24) as a therapeutic agent for PC, and evaluated its efficacy in preclinical models of PC. CMC2.24 inhibited the growth of various human PC cell lines in a concentration and time-dependent manner. Normal human pancreatic epithelial cells were resistant to CMC2.24, indicating selectivity. CMC2.24 reduced the growth of subcutaneous and orthotopic PC xenografts in mice by up to 65% (P < 0.02), and the growth of a human patient-derived tumor xenograft by 47.5% (P < 0.03 vs vehicle control). Mechanistically, CMC2.24 inhibited the Ras-RAF-MEK-ERK pathway. Based on Ras Pull-Down Assays, CMC2.24 inhibited Ras-GTP, the active form of Ras, in MIA PaCa-2 cells and in pancreatic acinar explants isolated from Kras mutant mice, by 90.3% and 89.1%, respectively (P < 0.01, for both). The inhibition of active Ras led to an inhibition of c-RAF, MEK, and ERK phosphorylation by 93%, 91%, and 87%, respectively (P < 0.02, for all) in PC xenografts. Furthermore, c-RAF overexpression partially rescued MIA PaCa-2 cells from the cell growth inhibition by CMC2.24. In addition, downstream of ERK, CMC2.24 inhibited STAT3 phosphorylation levels at the serine 727 residue, enhanced the levels of superoxide anion in mitochondria, and induced intrinsic apoptosis as shown by the release of cytochrome c from the mitochondria to the cytosol and the further cleavage of caspase 9 in PC cells. In conclusion, CMC2.24, a potential Ras inhibitor, is an efficacious agent for PC treatment in preclinical models, deserving further evaluation.

Curcumin formulated in solid lipid nanoparticles has enhanced efficacy in Hodgkin's lymphoma in mice.

Curcumin reduces Hodgkin's lymphoma (HL) cell growth in vitro, but its unfavorable pharmacokinetics highlight the need for novel in vivo delivery systems. Thus, we explored whether formulation of curcumin in solid lipid nanoparticles (SLN-curc) or d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (TPGS-curc) could enhance its efficacy in mice. Curcumin formulated in SLN and in TPGS resulted in higher curcumin plasma levels in mice. Compared to vehicle-treated controls, SLN-curc and TPGS-curc reduced HL xenograft growth by 50.5% (p < 0.02) and 43.0% (p < 0.04), respectively, while curcumin reduced it by 35.8% (p < 0.05). In addition, SLN-curc reduced the expression of proteins involved in cell proliferation and apoptosis (XIAP and Mcl-1) in HL tumor extracts. In HL cells in culture, curcumin decreased the expression of relevant anti-inflammatory cytokines (IL-6 and TNF-α) in a concentration-dependent manner. Moreover, when given in combination with bleomycin, doxorubicin and vinblastine, curcumin showed an additive growth inhibitory effect. In conclusion, SLNs appear as an appropriate and effective drug delivery system for curcumin. Given the efficacy of SLN-curc and the enhanced growth inhibitory effect when combined with chemotherapeutic drugs, we speculate that curcumin, when appropriately formulated, is a promising adjuvant agent for the treatment of HL and merits further evaluation.

Aldosterone activates the oncogenic signals ERK1/2 and STAT3 via redox-regulated mechanisms.

Epidemiological studies found an increased risk for kidney cancer in hypertensive patients, of which a subgroup has high aldosterone (Ald) levels. We recently showed that Ald is genotoxic both in kidney tubular cells and in rats with mineralocorticoid-mediated hypertension. The present work investigated in vitro and in vivo, if the oxidative stress-mediated activation of the ERK1/2 pathway, and its downstream target STAT3, could be one mechanism involved in the potential oncogenic capability of excess Ald exposure. The effects of excess Ald were investigated in LLC-PK1 cells and in Ald-induced hypertensive rats. Ald caused cRaf, MEK1/2, and ERK1/2 phosphorylation both in LLC-PK1 cells and in rat kidneys. ERK1/2 activation led to an increased phosphorylation of MSK1, p90RSK, and STAT3. The involvement of ERK1/2 in the activation of STAT3 was evidenced by the capacity of the MEK inhibitor U0126 to prevent Ald-mediated ERK1/2 and STAT3 phosphorylation. Both in vitro and in vivo, the activation of ERK1/2 and STAT3 by Ald was dependent on the mineralocorticoid receptor and was triggered by an increase in cellular oxidants. Ald-mediated oxidant increase was in part due to the activation of the enzymes NADPH oxidase and NO synthase. Proliferation was significantly enhanced and apoptosis decreased in Ald-treated rat kidneys and/or LLC-PK1 cells. Results support the concept that the oxidant-mediated long-term activation of ERK1/2/STAT3 by persistently high Ald levels could trigger proliferative and prosurvival events. Ald-mediated promotion of cell survival and DNA damage could result in kidney cell transformation and initiation of cancer in hypertensive patients with hyperaldosteronism.

The novel agent phospho-glycerol-ibuprofen-amide (MDC-330) inhibits glioblastoma growth in mice: an effect mediated by cyclin D1.

Given that glioblastoma multiforme (GBM) is associated with poor prognosis, new agents are urgently needed. We developed phospho-glycerol-ibuprofen-amide (PGIA), a novel ibuprofen derivative, and evaluated its safety and efficacy in preclinical models of GBM, and its mechanism of action using human GBM cells and animal tumor models. Furthermore, we explored whether formulating PGIA in polymeric nanoparticles could enhance its levels in the brain. PGIA was 3.7- to 5.1-fold more potent than ibuprofen in suppressing the growth of human GBM cell lines. PGIA 0.75× IC50 inhibited cell proliferation by 91 and 87% in human LN-229 and U87-MG GBM cells, respectively, and induced strong G1/S arrest.In vivo, compared with control, PGIA reduced U118-MG and U87-MG xenograft growth by 77 and 56%, respectively (P< 0.05), and was >2-fold more efficacious than ibuprofen. Normal human astrocytes were resistant to PGIA, indicating selectivity. Mechanistically, PGIA reduced cyclin D1 levels in a time- and concentration-dependent manner in GBM cells and in xenografts. PGIA induced cyclin D1 degradation via the proteasome pathway and induced dephosphorylation of GSK3ß, which was required for cyclin D1 turnover. Furthermore, cyclin D1 overexpression rescued GBM cells from the cell growth inhibition by PGIA. Moreover, the formulation of PGIA in poly-(L)-lactic acid poly(ethylene glycol) polymeric nanoparticles improved its pharmacokinetics in mice, delivering PGIA to the brain. PGIA displays strong efficacy against GBM, crosses the blood-brain barrier when properly formulated, reaching the target tissue, and establishes cyclin D1 as an important molecular target. Thus, PGIA merits further evaluation as a potential therapeutic option for GBM.

The PI3K/Akt pathway is involved in procyanidin-mediated suppression of human colorectal cancer cell growth.

Colorectal cancer (CRC) has the third highest incidence worldwide. Epidemiological studies showed that the consumption of fruit and vegetables containing procyanidins (PCA), polymers of flavan-3-ols, is associated with lower CRC risk. However, the molecular mechanisms supporting this positive association are unclear. This study investigated the capacity of PCA with different degrees of polymerization to reduce CRC cell growth, characterizing the underlying mechanisms. Compared to the monomer ((-)-epicatechin) and the trimer, the hexamer (Hex) was the most active at reducing CRC cell viability. Hex caused a concentration- (2.5-50 µM) and time- (24-72 h) dependent decrease in the viability of six human CRC cell lines in culture. Hex caused CRC apoptotic Caco-2 cell death within 24 h, as evidenced by caspase 3 and caspase 9 activation, DNA fragmentation, and changes in nuclear morphology/staining. Hex-induced apoptosis occurs through the mitochondrial pathway, as evidenced by an increased Bad mitochondrial translocation, and cytochrome c release from the mitochondria to the cytosol. Hex also arrested the Caco-2 cell cycle at G2 /M phase and upregulated genes involved in autophagy. Mechanistically, in Caco-2 cells Hex inhibited the PI3K/Akt signaling pathway, causing the downstream downregulation of proteins involved in the regulation of cell survival (Bad, GSK-3ß). Accordingly, the Akt inhibitor MKK-2206 decreased Bad and GSK-3ß phosphorylation. MKK-2206 decreased cell growth, having an additive effect with Hex. In conclusion, our results show that large PCA can inhibit CRC cell growth via the Akt kinase pathway, demonstrating a mechanism to explain the epidemiological evidence linking PCA-rich diets with lower CRC risk. © 2016 Wiley Periodicals, Inc.

Phospho-aspirin (MDC-22) inhibits breast cancer in preclinical animal models: an effect mediated by EGFR inhibition, p53 acetylation and oxidative stress.

BACKGROUND: The anticancer properties of aspirin are restricted by its gastrointestinal toxicity and its limited efficacy. Therefore, we synthesized phospho-aspirin (PA-2; MDC-22), a novel derivative of aspirin, and evaluated its chemotherapeutic and chemopreventive efficacy in preclinical models of triple negative breast cancer (TNBC). METHODS: Efficacy of PA-2 was evaluated in human breast cancer cells in vitro, and in orthotopic and subcutaneous TNBC xenografts in nude mice. Mechanistic studies were also carried out to elucidate the mechanism of action of PA-2. RESULTS: PA-2 inhibited the growth of TNBC cells in vitro more potently than aspirin. Treatment of established subcutaneous TNBC xenografts (MDA-MB-231 and BT-20) with PA-2 induced a strong growth inhibitory effect, resulting in tumor stasis (79% and 90% inhibition, respectively). PA-2, but not aspirin, significantly prevented the development of orthotopic MDA-MB-231 xenografts (62% inhibition). Mechanistically, PA-2: 1) inhibited the activation of epidermal growth factor receptor (EGFR) and suppressed its downstream signaling cascades, including PI3K/AKT/mTOR and STAT3; 2) induced acetylation of p53 at multiple lysine residues and enhanced its DNA binding activity, leading to cell cycle arrest; and 3) induced oxidative stress by suppressing the thioredoxin system, consequently inhibiting the activation of the redox sensitive transcription factor NF-κB. These molecular alterations were observed in vitro and in vivo, demonstrating their relevance to the anticancer effect of PA-2. CONCLUSIONS: Our findings demonstrate that PA-2 possesses potent chemotherapeutic efficacy against TNBC, and is also effective in its chemoprevention, warranting further evaluation as an anticancer agent.

A high-fat diet induces changes in mesenteric adipose tissue accelerating early-stage pancreatic carcinogenesis in mice.

Increased adiposity is a significant risk factor for pancreatic cancer development. Multiple preclinical studies have documented that high-fat, high calorie diets, rich in omega-6 fatty acids (FA) accelerate pancreatic cancer development. However, the effect of a high-fat, low sucrose diet (HFD), on pancreatic carcinogenesis remains unclear. We evaluated the impact of a HFD on early-stage pancreatic carcinogenesis in the clinically relevant KrasLSL-G12D/+; Ptf1aCre/+ (KC) genetically engineered mouse model, and characterized the role of the mesenteric adipose tissue (MAT). Cohorts of male and female KC mice were randomly assigned to a control diet (CD) or a HFD, matched for FA composition (9:1 of omega-6 FA: omega-3 FA), and fed their diets for 8 weeks. After 8 weeks on a HFD, KC mice had significantly higher body weight, fat mass, and serum leptin compared to CD-fed KC mice. Furthermore, a HFD accelerated pancreatic acinar-to-ductal metaplasia (ADM) and proliferation, associated with increased activation of ERK and STAT3, and macrophage infiltration in the pancreas, compared to CD-fed KC mice. Metabolomics analysis of the MAT revealed sex differences between diet groups. In females, a HFD altered metabolites related to FA (α-linolenic acid and linoleic acid) and amino acid metabolism (alanine, aspartate, glutamate). In males, a HFD significantly affected pathways related to alanine, aspartate, glutamate, linoleic acid, and the citric acid cycle. A HFD accelerates early pancreatic ADM through multifaceted mechanisms, including effects at the tumor and surrounding MAT. The sex-dependent changes in MAT metabolites could explain some of the sex differences in HFD-induced pancreatic ADM.

The anticancer effect of phospho-tyrosol-indomethacin (MPI-621), a novel phosphoderivative of indomethacin: in vitro and in vivo studies.

We have synthesized a novel derivative of indomethacin, phospho-tyrosol-indomethacin (PTI; MPI-621), and evaluated its anticancer efficacy in vitro and in vivo. PTI inhibited the growth of human colon, breast and lung cancer cell lines 6-30-fold more potently than indomethacin. In vivo, in contrast to indomethacin that was unable to inhibit colon cancer xenograft growth, PTI inhibited the growth of colon (69% at 10mg/kg/day, P < 0.01) and lung (91% at 15mg/kg/day, P < 0.01) subcutaneous cancer xenografts in immunodeficient mice, suppressing cell proliferation by 33% and inducing apoptosis by 75% (P < 0.05, for both). Regarding its pharmacokinetics in mice, after a single intraperitoneal injection of PTI, its plasma levels reached the maximum concentration (Cmax = 46 µM) at 2h (Tmax) and became undetectable at 4h. Indomethacin is the major metabolite of PTI, with plasma Cmax = 378 µM and Tmax = 2.5h; it became undetectable 24h postadministration. The cellular uptake of PTI (50-200 µM) at 6h was about 200-fold greater than that of indomethacin. Regarding its safety, PTI had no significant genotoxicity, showed less gastrointestinal toxicity than indomethacin and presented no cardiac toxicity. Mechanistically, PTI suppressed prostaglandin E2 production in A549 human lung cancer cells and strongly inhibited nuclear factor-κB activation in A549 xenografts. These findings indicate that PTI merits further evaluation as an anticancer agent.

Topically applied phospho-sulindac hydrogel is efficacious and safe in the treatment of experimental arthritis in rats.

PURPOSE: Formulate phospho-sulindac (P-S, OXT-328) in a Pluronic hydrogel to be used as a topical anti-inflammatory agent and study its efficacy, safety and pharmacokinetics in an arthritis model. METHODS: LEW/crlBR rats with Freund's adjuvant-induced arthritis were treated with P-S formulated in Pluronic hydrogel (PSH). We determined the clinical manifestations of arthritis including the locomotor activity of the rats; evaluated joints for inflammation, bone resorption, cartilage damage, COX-2 expression and NF-κB activation; assayed plasma IL-6 and IL-10 levels; and studied the pharmacokinetics of P-S in rats after topical or oral administration. RESULTS: PSH applied at the onset of arthritis or when arthritis was fully developed, suppressed it by 56-82%, improved the locomotor activity of the rats 2.1-4.4 fold, suppressed synovial inflammation, bone resorption, cartilage damage, NF-κB activation and COX-2 expression but not plasma IL-6 and IL-10 levels. There were no side effects. PSH produced rapidly high local levels of P-S with <14% of P-S reaching the circulation, while orally administered P-S was rapidly metabolized generating much lower joint levels of P-S. CONCLUSIONS: Topical application of PSH is efficacious and safe in the treatment of Freund's adjuvant-induced arthritis; has a favorable pharmacokinetic profile; and likely acts by suppressing key pro-inflammatory signaling pathways.

Chlorogenic acid combined with epigallocatechin-3-gallate mitigates D-galactose-induced gut aging in mice.

Chlorogenic acid (CGA) and epigallocatechin-3-gallate (EGCG) are major polyphenolic constituents of coffee and green tea with beneficial health properties. In this study, we evaluated the gut protecting effect of CGA and EGCG, alone or in combination, on D-galactose-induced aging mice. CGA plus EGCG more effectively improved the cognition deficits and protected the gut barrier function, compared with the agents alone. Specifically, CGA plus EGCG prevented the D-galactose mediated reactive oxygen species accumulation by increasing the total antioxidant capacity, reducing the levels of malondialdehyde, and suppressing the activity of the antioxidant enzymes superoxide dismutase and catalase. In addition, supplementation of CGA and EGCG suppressed gut inflammation by reducing the levels of the proinflammatory cytokines TNFα, IFNγ, IL-1ß and IL-6. Moreover, CGA and EGCG modulated the gut microbiome altered by D-galactose. For instance, CGA plus EGCG restored the Firmicutes/Bacteroidetes ratio of the aging mice to control levels. Furthermore, CGA plus EGCG decreased the abundance of Lactobacillaceae, Erysipelotrichaceae, and Deferribacteraceae, while increased the abundance of Lachnospiraceae, Muribaculaceae, and Rikenellaceae, at the family level. In conclusion, CGA in combination with EGCG ameliorated the gut alterations induced by aging, in part, through antioxidant and anti-inflammatory effects, along with its gut microbiota modulatory capacity.

Hepatic safety profile of pancreatic cancer­bearing mice fed a ketogenic diet in combination with gemcitabine.

Ketogenic diets (KDs) are actively being evaluated for their potential anticancer effects. Although KDs are generally considered safe, their safety profile when combined with chemotherapy remains unknown. It is known that a KD enhances the anticancer effect of gemcitabine (2',2'-difluoro-2'-deoxycytidine) in LSL-KrasLSL-G12D/+Trp53R172H/+Pdx-1-Cre (KPC) tumor-bearing mice. In the present study, whether a KD in combination with gemcitabine affected the liver safety profile in KPC mice was evaluated. For this purpose, male and female pancreatic tumor-bearing KPC mice were allocated to a control diet (CD; % kcal: 20% fat, 65% carbohydrate, 15% protein) + gemcitabine [control plus gemcitabine group (CG)] or a KD (% kcal: 84% fat, 15% protein, 1% carbohydrate) + gemcitabine [ketogenic plus gemcitabine group (KG)] for two months. After two months of treatment, no significant differences in body weight were observed between CGs and KGs. Moreover, the KD did not significantly alter the serum protein expression levels of liver enzymes, including aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase. In addition, the KD did not alter markers of liver-lipid accumulation as well as serum cholesterol and triglyceride levels, compared with the CG-treated group. Upon histologic examination, steatosis was rare, with no notable differences between treatment groups. When examining liver fatty acid composition, KD treatment significantly increased the content of saturated fatty acids and significantly decreased levels of cis-monounsaturated fatty acids compared with the CG. Finally, the KD did not affect liver markers of inflammation and oxidative stress, nor the protein expression levels of enzymes involved in ketone bodies, such as 3-hydroxy-3-methylglutaryl-CoA lyase and hidroximetilglutaril-CoA sintasa, and glucose metabolism, such as hexokinase 2, pyruvate dehydrogenase and phosphofructokinase. In summary, a KD in combination with gemcitabine appears to be safe, with no apparent hepatotoxicity and these data support the further evaluation of a KD as an adjuvant dietary treatment for pancreatic cancer.

Phospho-ibuprofen (MDC-917) suppresses breast cancer growth: an effect controlled by the thioredoxin system.

INTRODUCTION: We have recently synthesized phospho-ibuprofen (P-I; MDC-917), a safer derivative of ibuprofen, which has shown anti-cancer activity. We investigated its efficacy and mechanism of action in the treatment of breast cancer in preclinical models. METHODS: We evaluated the anti-breast-cancer efficacy of P-I alone or incorporated into liposomes (Lipo-P-I) in human estrogen receptor-positive (MCF-7) and triple-negative, i.e., estrogen receptor-negative, progesterone receptor-negative and HER2-negative (MDA-MB231) breast cancer cell lines - as they represent the most frequent (estrogen receptor-positive) and the most difficult-to-treat (triple-negative) subtypes of breast cancer - and their xenografts in nude mice. We assessed the effect of P-I on the levels of reactive oxygen nitrogen species in response to P-I using molecular probes, on the thioredoxin system (expression and redox status of thioredoxin-1 (Trx-1) and thioredoxin reductase activity), on cyclooxygenase 2, NF-κB and mitogen-activated protein kinase cell signaling; and on the growth of xenografts with stably knocked-down Trx-1. RESULTS: Compared with controls, P-I 400 mg/kg/day inhibited the growth of MDA-MB231 xenografts by 266%, while the growth of MCF-7 xenografts was inhibited 51% byP-I 300 mg/kg/day and 181% by Lipo-P-I 300 mg/kg/day. In both cell lines, P-I induced oxidative stress and suppressed the thioredoxin system (oxidized Trx-1 and decreased its expression; inhibited thioredoxin reductase activity). These changes triggered downstream redox signaling: the activity of NF-κB was suppressed and the Trx-1-ASK1 complex was dissociated, activating the p38 and JNK mitogen-activated protein kinase cascades. Trx-1 knockdown abrogated the anti-cancer effect of P-I in vitro and in vivo. CONCLUSION: P-I is safe and effective against breast cancer. Liposomal formulation enhances its efficacy; the effect is heavily dependent on the induction of oxidative stress and the suppression of the thioredoxin system. P-I merits further evaluation as an agent for the treatment of breast cancer.

Phospho-Aspirin (MDC-22) inhibits pancreatic cancer growth in patient-derived tumor xenografts and KPC mice by targeting EGFR: Enhanced efficacy in combination with irinotecan.

Novel therapeutic strategies are needed in the fight against pancreatic cancer. We have previously documented the chemopreventive effect of MDC-22 in preclinical models of pancreatic cancer. In the present work, we examined the therapeutic effects of MDC-22 in patient-derived tumor xenografts (PDTXs) and in LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre (KPC) genetically engineered mice, two complementary and clinically relevant animal models of pancreatic cancer. In addition, we evaluated whether MDC-22 could synergize with current chemotherapeutic drugs used in the clinic. MDC-22 reduced the growth of various human pancreatic cancer cell lines in a concentration-dependent manner. In vivo, MDC-22 strongly reduced patient-derived pancreatic tumor xenograft growth by 50%, and extended survival of LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) mice by over a month (5.3 months versus 7.0 months). In both models, MDC-22 inhibited EGFR activation and its downstream signals, including ERK and FAK phosphorylation. In human pancreatic cancer cell lines, MDC-22 enhanced the growth inhibitory effect of irinotecan, and to a lesser degree those of gemcitabine and nab-paclitaxel. Normal human pancreatic epithelial cells were more resistant to the cytotoxic effects of, both, MDC-22 alone or in combination with irinotecan, indicating selectivity. Furthermore, MDC-22 enhanced irinotecan's effect on cell migration, in part, by inhibiting EGFR/FAK signaling. Collectively, our results indicate that MDC-22 is an effective anticancer drug in preclinical models of pancreatic cancer, and suggest that MDC-22 plus irinotecan as drug combination strategy for pancreatic cancer treatment, which warrants further evaluation.

Correction: A Ketogenic Diet in Combination with Gemcitabine Increases Survival in Pancreatic Cancer KPC Mice.

[This corrects the article DOI: 10.1158/2767-9764.CRC-22-0256.][This corrects the article DOI: 10.1158/2767-9764.CRC-22-0256.].

A ketogenic diet in combination with gemcitabine increases survival in pancreatic cancer KPC mice.

Pancreatic ductal adenocarcinoma (PDAC) continues to be a major health problem. A ketogenic diet (KD), characterized by a very low carbohydrate and high fat composition, has gained attention for its anti-tumor potential. We evaluated the effect and mechanisms of feeding a strict KD alone or in combination with gemcitabine in the autochthonous LSL-KrasG12D/+; LSL-Trp53 R172H/+; Pdx1-Cre (KPC) mouse model. For this purpose, both male and female pancreatic tumor-bearing KPC mice were allocated to a control diet (CD; %kcal: 70% carb, 14% protein, 16% fat), a KD (%kcal: 14% protein, 1% carb, 85% fat), a CD + gemcitabine (CG), or a KD + gemcitabine (KG) group. Mice fed a KD alone or in combination with gemcitabine showed significantly increased blood ß-hydroxybutyrate levels compared to mice fed a CD or CG. KPC mice fed a KG had a significant increase in overall median survival compared to KPC mice fed a CD (increased overall median survival by 42%). Interestingly, when the data was disaggregated by sex, the effect of a KG was significant in female KPC mice (60% increase in median overall survival), but not in male KPC mice (28% increase in median overall survival). Mechanistically, the enhanced survival response to a KD combined with gemcitabine was multifactorial, including inhibition of ERK and AKT pathways, regulation of fatty acid metabolism and the modulation of the gut microbiota. In summary, a KD in combination with gemcitabine appears beneficial as a treatment strategy in PDAC in KPC mice, deserving further clinical evaluation.

The plasma membrane plays a central role in cells response to mechanical stress.

The mechanisms by which lymphocytes recognize and interpret mechanical stimuli and translate these into the triggering of select signaling cascades that are critical for lymphocyte function are still not fully understood. In this work, we investigated the association of mechanical stress (MS)-induced changes in membrane physical properties with changes in cytoskeleton dynamics and cell signaling. In Jurkat T cells, MS was associated with the immediate and transient depolymerization of both beta-tubulin and F-actin. The fluidity of the plasma membrane measured in the hydrophobic region of the bilayer, increased 0.5 min post-MS, recovering the initial value in the following 2 min. This effect was accompanied by the rearrangement of lipids in the lateral phase of the plasma membrane, transient lipid rafts' alteration, and membrane hyperpolarization. The consequent increase in cellular [Ca2+] triggered the activation of the transcription factors NFAT, AP-1, and NF-kappaB. Results indicate that the cytoplasmic membrane, through changes in membrane physical properties, senses MS, and transduces an initial physical stimulus into microtubules rearrangements, Ca2+ mobilization, and the subsequent changes in cell signaling.