The Effects of Combination Treatment Using Phenoxodiol and Docetaxel, and Phenoxodiol and Secreted Frizzled-related Protein 4 on Prostate Cancer Cell Lines

Although much progress has been made for the treatment of prostate cancer, patients with advanced prostate cancer still have a poor 5 year survival rate. Current practices for hormone-refractory/castrate resistant, metastatic prostate cancer involve the use of taxanes. Docetaxel, in particular, is being incorporated in numerous current clinical trials either as a single or combination agent against androgen-independent prostate cancer. Combination therapies have the potential to increase the effectiveness of drug treatments while simultaneously increasing quality of life by reducing side effects, lowering effective dosage rates, or by increasing effectiveness of one compound once combined with another. Using three diverse human prostate cancer cell lines, LNCap, DU145, and PC3, we studied the effect of the novel prostate cancer drug phenoxodiol in combination with docetaxel by utilizing isobolograms, and found that docetaxelinduced cell death was attenuated by co-treatment or pre-treatment of cells with phenoxodiol. This attenuation is associated with the prevention of cells from entering the G2/M phase of the cell cycle where docetaxel is functional in damaging the spindle fibers, and potentially due to p21WAF1 mediated cell survival after docetaxel treatment.We also investigated the use of the Wnt signaling pathway antagonist secreted frizzled-related protein 4 (sFRP4) to increase the effectiveness of phenoxodiol treatment. We found that, through stabilization of the GSK3β molecule, sFRP4 induces degradation of active β-catenin, which causes an increased sensitivity to isoflavone cytotoxic induction by increasing p21WAF1 expression and decreasing expression of c-Myc, Cyclin-D1, and other potent oncogenes. Phenoxodiol induces significant cytotoxicity when combined with a Wnt/β-catenin receptor blocker such as sFRP4. This promotes the concept that combination therapy of a Wnt inhibitor with phenoxodiol might increase the effectiveness of phenoxodiol and give a subset population of prostate cancer sufferers a more effective treatment regime

The Role of Secreted Frizzled Related Protein 4 (sFRP-4) in Regulating Oestradiol-Induced Growth of the MCF-7 Breast Cancer Cell Line

The Wnt signalling pathway is involved in regulating cellular proliferation and differentiation, and aberrant activation has been described in several cancers including breast. Oestradiol up regulates Wnt pathway gene expression, and thereby activates the Wnt signalling pathway. We used the oestrogen-responsive breast cancer cell line MCF-7 to examine the effects of secreted frizzled related protein 4 (sFRP-4) on oestradiol-induced growth, including gene expression of the Wnt signalling pathway genes Frizzled Receptor, Wnt-10b, and β-catenin. We demonstrate here that sFRP-4 inhibits oestradiol-induced cell growth in the MCF-7 cell line and also down regulates oestradiol-induced expression of selected Wnt signalling genes including β-catenin. We propose that sFRP-4 is a potent inhibitor of the Wnt signalling pathway and may negatively regulate oestradiol-mediated proliferation in human breast cancer cells

HP1 reshapes nucleosome core to promote phase separation of heterochromatin

Heterochromatin affects genome function at many levels. It enables heritable gene repression, maintains chromosome integrity and provides mechanical rigidity to the nucleus1,2. These diverse functions are proposed to arise in part from compaction of the underlying chromatin2. A major type of heterochromatin contains at its core the complex formed between HP1 proteins and chromatin that is methylated on histone H3, lysine 9 (H3K9me). HP1 is proposed to use oligomerization to compact chromatin into phase-separated condensates3-6. Yet, how HP1-mediated phase separation relates to chromatin compaction remains unclear. Here we show that chromatin compaction by the Schizosaccharomyces pombe HP1 protein Swi6 results in phase-separated liquid condensates. Unexpectedly, we find that Swi6 substantially increases the accessibility and dynamics of buried histone residues within a nucleosome. Restraining these dynamics impairs compaction of chromatin into liquid droplets by Swi6. Our results indicate that Swi6 couples its oligomerization to the phase separation of chromatin by a counterintuitive mechanism, namely the dynamic exposure of buried nucleosomal regions. We propose that such reshaping of the octamer core by Swi6 increases opportunities for multivalent interactions between nucleosomes, thereby promoting phase separation. This mechanism may more generally drive chromatin organization beyond heterochromatin

Diuretic activity of ethanolic extract of whole plant of Sphaeranthus indicus linn in albino rats

Background: Sphaeranthus indicus Linn (S. indicus Linn) is a medicinal plant widely used in Indian traditional system of medicine for treating various ailments. The aim of the study was to evaluate diuretic activity by Lipschitz method in albino rats.Methods: Thirty albino rats were grouped into five groups and each contained six rats. Group I (control group) received 25ml/kg each of 0.9% sodium chloride orally. Group II (standard) received Hydrochlorothiazide 25 mg/kg orally dissolved in isotonic normal saline. Groups III, IV and V received ethanolic extracts of S. indicus Linn in doses 100mg/kg, 200mg/kg and 300mg/kg respectively dissolved in isotonic saline orally. The mice were put in metabolic cages and urine samples were collected for all the groups up to 24 hours after dosing. Urine was analysed for volume, urinary excretion ratio, diuretic activity, sodium and potassium composition electrolytes. Data was analysed using SPSS version 16 for windows.Results: Single dose administration of S. indicus in doses of 100, 200 and 300 mg/Kg as compared to Hydrochlorothiazide (25 mg/kg)have significantly (p<0.001, ANOVA) increased total urine output along with an increase in concentration of sodium and potassium. S. indicus Linn 300 mg/Kg produced greater diuretic activity, which is comparable to the effect of standard.Conclusions: The extract treated rats showed a dose dependent increase in urine volume. Maximum diuretic and kaliuretic activity were observed at the dose of 300 mg/kg of the extract. The present study supports and confirms the basis for folklore use of S. indicus Linn as a diuretic agent

The incidence and risk factors for development of lower limb lymphedema after treatment for gynaecological cancers

Background: The development of postoperative lower limb lymphedema (LLL) is a disabling, yet usually overlooked sequele of most gynecological cancer treatment. It can lead to significant functional problems that negatively affect gynecological cancer survivors’ daily living, work, emotional state, and overall quality of life. The objective of this study is to calculate the incidence of lower limb lymphedema in patients undergoing surgery for gynecological cancer and to evaluate the risk factors for its development.Methods: Women with newly diagnosed carcinoma ovary, carcinoma endometrium and carcinoma cervix, who underwent surgery at a tertiary cancer centre from September 2016 were included in the study. The circumference of both lower limbs was measured at prefixed sites. The limb volume was calculated using the formula C2/pi. A baseline value was taken prior to surgery. The patients were followed up every 3 months and the limb volume were calculated at each visit. An increase in limb volume by >10% was defined as lymphedema.Results: The incidence of lymphedema after 1 year follow up was 43.5%. There was no significant association between known risk factors such as extent of lymphadenectomy (p value 0.633) number of pelvic or para aortic lymph nodes removed (p value 0.69 and 0.44 respectively) and type of adjuvant therapy (p value 0.455).Conclusions: The incidence of LLL according to the present study was 43.5%. There was no statistically significant association between development of LLL and risk factors like site and number of lymph nodes removed and type of adjuvant therapy

SFRP4 signalling of apoptosis and angiostasis uses nitric oxide-cGMP-permeability axis of endothelium

Nitric oxide (NO) plays a critical role in endothelial functions such as cellular migration, vascular permeability and angiogenesis. Angiogenesis, the formation of new blood vessels from "pre-existing" ones is a carefully regulated process and essential during reproduction, development and wound healing. Previously our lab group reported that Secreted Frizzled-Related Protein 4 (sFRP4) could inhibit angiogenesis in both in vitro and in vivo conditions. sFRP4 belongs to a family of secreted glycoproteins that function as antagonists of the canonical Wnt signalling pathway. Although the pro-apoptotic role of sFRP4 is well discussed in literature, little is known in regards to its anti-angiogenic property. The objective of this study was to elucidate sFRP4 implications in NO biology of the endothelium. Results demonstrate that sFRP4 causes endothelial dysfunction by suppressing NO-cGMP signaling and elevating corresponding ROS levels. The imbalance between NO and ROS levels results in apoptosis and subsequent leakiness of endothelium as confirmed in vivo (Texas red/Annxin - CAM assay) and in vitro (Monolayer permeability assay) conditions. Furthermore utilizing peptides synthesized from the CRD domain of sFRP4, our results showed that while these peptides were able to cause endothelial dysfunctions, they did not cause apoptosis of the endothelial cells. Thereby confirming that sFRP4 can mediate its anti-angiogenic effect independent of its pro-apoptotic property. In conclusion, the current study reports that sFRP4-mediated anti-angiogenesis occurs as a result of impaired NO-cGMP signaling which in turn allow for elevation of redox levels and promotion of apoptosis of endothelial cells

Multi-lineage differentiation of mesenchymal stem cells - To Wnt, or not Wnt

Mesenchymal stem cells (MSCs) are multipotent precursor cells originating from several adult connective tissues. MSCs possess the ability to self-renew and differentiate into several lineages, and are recognized by the expression of unique cell surface markers. Several lines of evidence suggest that various signal transduction pathways and their interplay regulate MSC differentiation. To that end, a critical player in regulating MSC differentiation is a group of proteins encoded by the Wnt gene family, which was previously known for influencing various stages of embryonic development and cell fate determination. As MSCs have gained significant clinical attention for their potential applications in regenerative medicine, it is imperative to unravel the mechanisms by which molecular regulators control differentiation of MSCs for designing cell-based therapeutics. It is rather coincidental that the functional outcome(s) of Wnt-induced signals share similarities with cellular redox-mediated networks from the standpoint of MSC biology. Furthermore, there is evidence for a crosstalk between Wnt and redox signalling, which begs the question whether Wnt-mediated differentiation signals involve the intermediary role of reactive oxygen species. In this review, we summarize the impact of Wnt signalling on multi-lineage differentiation of MSCs, and attempt to unravel the intricate interplay between Wnt and redox signals

Targeting the PI3K/Akt signaling pathway in gastric carcinoma: A reality for personalized medicine?

Frequent activation of phosphatidylinositol-3 kinases (PI3K)/Akt/mTOR signaling pathway in gastric cancer (GC) is gaining immense popularity with identification of mutations and/or amplifications of PIK3CA gene or loss of function of PTEN, a tumor suppressor protein, to name a few; both playing a crucial role in regulating this pathway. These aberrations result in dysregulation of this pathway eventually leading to gastric oncogenesis, hence, there is a need for targeted therapy for more effective anticancer treatment. Several inhibitors are currently in either preclinical or clinical stages for treatment of solid tumors like GC. With so many inhibitors under development, further studies on predictive biomarkers are needed to measure the specificity of any therapeutic intervention. Herein, we review the common dysregulation of PI3K/Akt/mTOR pathway in GC and the various types of single or dual pathway inhibitors under development that might have a superior role in GC treatment. We also summarize the recent developments in identification of predictive biomarkers and propose use of predictive biomarkers to facilitate more personalized cancer therapy with effective PI3K/Akt/mTOR pathway inhibition