Chemoprevention refers to the use of agents to inhibit, reverse or retard tumorigenesis. Numerous phytochemicals derived from edible plants have been reported to interfere with a specific stage of the carcinogenic process. Many mechanisms have been shown to account for the anticarcinogenic actions of dietary constituents, but attention has recently been focused on intracellular-signalling cascades as common molecular targets for various chemopreventive phytochemicals.

Cancer chemoprevention with dietary phytochemicals

Curcumin: The story so far

Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

Curcumin: The Indian solid gold

Curcumin inhibits proliferation, invasion, angiogenesis and metastasis of different cancers through interaction with multiple cell signaling proteins.

WNT–β-catenin signalling is involved in a multitude of developmental processes and the maintenance of adult tissue homeostasis by regulating cell proliferation, differentiation, migration, genetic stability and apoptosis, as well as by maintaining adult stem cells in a pluripotent state. Not surprisingly, aberrant regulation of this pathway is therefore associated with a variety of diseases, including cancer, fibrosis and neurodegeneration. Despite this knowledge, therapeutic agents specifically targeting the WNT pathway have only recently entered clinical trials and none has yet been approved. This Review examines the problems and potential solutions to this vexing situation and attempts to bring them into perspective.

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Can we safely target the WNT pathway

The development of nontoxic natural agents with chemopreventive activity against colon cancer is the focus of investigation in many laboratories. Curcumin (feruylmethane), a natural plant product, possesses such chemopreventive activity, but the mechanisms by which it prevents cancer growth are not well understood. In the present study, we examined the mechanisms by which curcumin treatment affects the growth of colon cancer cells in vitro. Results showed that curcumin treatment causes p53- and p21-independent G(2)/M phase arrest and apoptosis in HCT-116(p53(+/+)), HCT-116(p53(-/-)) and HCT-116(p21(-/-)) cell lines. We further investigated the association of the beta-catenin-mediated c-Myc expression and the cell-cell adhesion pathways in curcumin-induced G(2)/M arrest and apoptosis in HCT-116 cells. Results described a caspase-3-mediated cleavage of beta-catenin, decreased transactivation of beta-catenin/Tcf-Lef, decreased promoter DNA binding activity of the beta-catenin/Tcf-Lef complex, and decreased levels of c-Myc protein. These activities were linked with decreased Cdc2/cyclin B1 kinase activity, a function of the G(2)/M phase arrest. The decreased transactivation of beta-catenin in curcumin-treated HCT-116 cells was unpreventable by caspase-3 inhibitor Z-DEVD-fmk, even though the curcumin-induced cleavage of beta-catenin was blocked in Z-DEVD-fmk pretreated cells. The curcumin treatment also induced caspase-3-mediated degradation of cell-cell adhesion proteins beta-catenin, E-cadherin and APC, which were linked with apoptosis, and this degradation was prevented with the caspase-3 inhibitor. Our results suggest that curcumin treatment impairs both Wnt signaling and cell-cell adhesion pathways, resulting in G(2)/M phase arrest and apoptosis in HCT-116 cells.

β-Catenin-mediated transactivation and cell–cell adhesion pathways are important in curcumin (diferuylmethane)-induced growth arrest and apoptosis in colon cancer cells

The conclusion drawn by the authors of the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial is that antimicrobial prophylaxis reduces the risk of recurrent urinary tract infection (UTI)—but not of renal scarring—in patients with vesicoureteral reflux (VUR). A review of the findings showed that the decreased recurrent UTI rate was only present at the end of the 2-year follow-up period and was only slightly increased (12.3 %) above the 10 % cutoff for statistical significance. The difference was not observed in children younger than two years of age with VUR grade III and IV. In addition, the rate of new renal scarring was not statistically different between the prophylaxis and placebo groups (8.2 vs. 8.4 %, respectively). A high rate of uropathogen antibiotic resistance was observed in the prophylaxis group (68.4 vs. 24.6 %, respectively). The analysis of the RIVUR findings questions the validity of its authors suggestion that the results may warrant reconsideration of the current recommendations by the American Academy of Pediatrics on obtaining a voiding cystourethrogram after the first febrile UTI and the use of urinary antibiotic prophylaxis in VUR patients.

The RIVUR study: a review of its findings

BK virus (BKV) is a human polyomavirus with a seroprevalence of 60–80 % in the general population. In renal transplant patients, it is known to cause renal failure, ureteric stenosis and hemorrhagic cystitis. In bone marrow transplant patients, it is evident that BKV can also cause hemorrhagic cystitis along with BK virus nephropathy (BKVN) in the native kidneys, with subsequent renal failure. However, little is known about BVKN in non-transplanted immune-compromised patients, such as systemic lupus erythematosus (SLE) who may have underlying nephritis and have a compromised immune system due to therapy and/or systemic illness. Thus, this article will focus on the clinical aspects of BKV and its association in patients with SLE.

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Review article: BK virus in systemic lupus erythematosus

Background Membranoproliferative glomerulonephritis (MPGN type I, II and III) was reclassified in 2013 as MPGN and C3 glomerulopathy (C3G) based on the complement system activation mechanism. Objectives To evaluate whether C4d, a component of the classical pathway, could be a diagnostic tool in differentiating between MPGN and C3G. Methods We conducted a retrospective study of 15 MPGN type I, II and III and 13 minimal change disease (MCD) patients diagnosed between 2000 and 2012. C4d staining using the peroxidase method was employed. Results Using the 2013 C3G consensus classification, the 15 MPGN types I, II and III biopsies were re-classified as MPGN (8) and C3G (7). Following C4d staining, of the 8 biopsies diagnosed as MPGN, 4 had classical pathway involvement [C1q (+), C3 (+), C4d (+)]; two had lectin pathway involvement [C1q (−), C3 (+), C4d (+)]; and, two were reclassified as C3G because the absence of C4d and C1q suggested the presence of the alternative pathway [C1q (−), C3 (+), C4d (−)]. Three of the seven C3G biopsies presented classical pathway involvement and were reclassified as MPGN. The alternative pathway was present in one of the other 4 biopsies considered to be C3G. Two C3G biopsies involved the lectin pathway and the one case of dense deposit disease had lectin pathway involvement. Conclusions C4d staining may help to differentiate between MPGN and C3G. In addition, the lectin pathway could play a role in the pathogenesis of these glomerulopathies.

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Use of C4d as a diagnostic tool to classify membranoproliferative glomerulonephritis.

Fanconi-Bickel syndrome (FBS), also known as glycogen storage disease type XI (GSD XI), is a rare autosomal recessive disorder of carbohydrate metabolism. It is caused by mutations in the gene SLC2A2, which encodes for the facilitative glucose transporter GLUT2. Diagnosis of FBS is often delayed since the clinical features and laboratory markers often overlap with other disorders whose characteristic features include short stature, fasting hypoglycemia, postprandial hyperglycemia, hepatomegaly, hypophosphatemic rickets, and proximal renal tubular dysfunction. In this article, we present a case of FBS and its management in an African American female who initially presented with persistent proximal tubulopathy, hypercalciuria, and metabolic acidosis. We also include a recent literature review on FBS and discuss other metabolic disorders that should be considered in the differential diagnosis.

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Nirupama Gupta

Papers

β-Catenin-mediated transactivation and cell–cell adhesion pathways are important in curcumin (diferuylmethane)-induced growth arrest and apoptosis in colon cancer cells

The RIVUR study: a review of its findings

Review article: BK virus in systemic lupus erythematosus

Use of C4d as a diagnostic tool to classify membranoproliferative glomerulonephritis.

Late Diagnosis of Fanconi-Bickel Syndrome: Challenges With the Diagnosis and Literature Review