Recent advances in cancer stem/progenitor cell research: therapeutic implications for overcoming resistance to the most aggressive cancers.

Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers. This review summarizes recent advances in our understanding of the cellular origin and molecular mechanisms at the basis of cancer initiation and progression as well as the heterogeneity of cancers arising from the malignant transformation of adult stem/progenitor cells. We describe the critical functions provided by several growth factor cascades, including epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR), stem cell factor (SCF) receptor (KIT), hedgehog and Wnt/beta-catenin signalling pathways that are frequently activated in cancer progenitor cells and are involved in their sustained growth, survival, invasion and drug resistance. Of therapeutic interest, we also discuss recent progress in the development of new drug combinations to treat the highly aggressive and metastatic cancers including refractory/relapsed leukaemias, melanoma and head and neck, brain, lung, breast, ovary, prostate, pancreas and gastrointestinal cancers which remain incurable in the clinics. The emphasis is on new therapeutic strategies consisting of molecular targeting of distinct oncogenic signalling elements activated in the cancer progenitor cells and their local microenvironment during cancer progression. These new targeted therapies should improve the efficacy of current therapeutic treatments against aggressive cancers, and thereby preventing disease relapse and enhancing patient survival

A novel molybdenum oxide-Starbon catalyst for wastewater remediation

The exploration of novel media for environmental remediation, in particular wastewater treatment, is a global imperative. Herein, the in situ green synthesis, characterisation and application of a novel Starbon™ composite comprising molybdenum oxide nanoparticles are reported. Starbons™ are carbonaceous mesoporous materials derived from starch with applications ranging from chromatography to gas capture. The molybdenum (Mo) loading, evidenced by inductively coupled plasma-mass spectrometry (ICP-MS), was 179.337 mg g-1, and the molybdenum oxide nanoparticles were observed via transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). The Mo-containing composite was an efficient catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride, NaBH4 (k = 11.2 × 10-2 min-1). The Mo-composite showed superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical quenching activity with a low inhibitory concentration [IC50 = 1.006 mg ml-1] and ferric reducing power compared with other green synthesised composites and nanoparticles. The novel Mo-containing Starbon™ composite has real time applications in water treatment such as in catalysis, adsorption and filtration

Enhanced Wastewater Remediation Using Mesoporous Activated Wheat Straw Biochars: A Dye Removal Perspective

The escalating contamination of water bodies by synthetic dyes necessitates innovative and ecoconscious strategies for wastewater treatment. In this study, activated biochars BC-800 (1:0.25), BC-800 (1:0.5), and BC-800 (1:1) from wheat straw were synthesized. Here, ratios denote the mass relationship between wheat straw and potassium hydroxide; “800” represents the pyrolysis temperature. These activated biochars were rigorously characterized revealing the most efficient material, BC-800 (1:1), presenting a surface area of 2578.82 m2/g and average pore diameter of 5.51 nm. Across parallel batch experiments, it effectively extracted synthetic dyes (rhodamine B (RhB), methylene blue (MB), and methyl orange (MO)) from wastewater within 15–20 min, primarily through chemisorption pathways. Increased surface area and porosity resulted in a greater dispersion of adsorption sites including C═C linkages (π–π interactions) and H-bonding via surface carbonyl groups (C═O). To understand the adsorption mechanism, Langmuir, Freundlich, and Temkin isotherm models were employed to investigate the equilibrium adsorption behavior. Results show that BC-800 (1:1) followed the Freundlich isotherm (R2: 0.9659 for RhB, 0.9927 for MB, and 0.9979 for MO, respectively), showing dye molecules form multilayers on the surface of the biochar (π-stacking). Biochar recycling through chemical regeneration demonstrated sustained dye removal efficiency >90% for BC-800 (1:1) over multiple cycles

Retinoids Regulate the Formation and Degradation of Gap Junctions in Androgen-Responsive Human Prostate Cancer Cells

The retinoids, the natural or synthetic derivatives of Vitamin A (retinol), are essential for the normal development of prostate and have been shown to modulate prostate cancer progression in vivo as well as to modulate growth of several prostate cancer cell lines. 9-cis-retinoic acid and all-trans-retinoic acid are the two most important metabolites of retinol. Gap junctions, formed of proteins called connexins, are ensembles of intercellular channels that permit the exchange of small growth regulatory molecules between adjoining cells. Gap junctional communication is instrumental in the control of cell growth. We examined the effect of 9-cis-retinoic acid and all-trans retinoic acid on the formation and degradation of gap junctions as well as on junctional communication in an androgen-responsive prostate cancer cell line, LNCaP, which expressed retrovirally introduced connexin32, a connexin expressed by the luminal cells and well-differentiated cells of prostate tumors. Our results showed that 9-cis-retinoic acid and all-trans retinoic acid enhanced the assembly of connexin32 into gap junctions. Our results further showed that 9-cis-retinoic acid and all-trans-retinoic acid prevented androgen-regulated degradation of gap junctions, post-translationally, independent of androgen receptor mediated signaling. Finally, our findings showed that formation of gap junctions sensitized connexin32-expressing LNCaP cells to the growth modifying effects of 9-cis-retinoic acid, all-trans-retinoic acid and androgens. Thus, the effects of retinoids and androgens on growth and the formation and degradation of gap junctions and their function might be related to their ability to modulate prostate growth and cancer

Novel diterpene rearrangements: dichotomous behaviour of abietic-type resin acids in strong acid medium

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Stereochemistry of isolongifolene ketones

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Novel fragmentation of longibornane system: synthons for α -longipinene synthesis

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Reaction of gem-dibromocyclopropanes with zinc in dimethylformamide

Dehalogenation of five assorted gem-dibromocyclopropanes with zinc in dimethylformamide is described. Monobromocyclopropanes, allenes are fully saturated cyclopropanes are obtained. The method is of preparative value only in certain cases

A convenient dehalogenation of organic halides via organozinc compounds

A simple, nonreductive procedure for the dehalogenation of organic halides to hydrocarbons is described, involving treatment with zinc in dimethylformamide followed by hydrolysis

Rearrangement of abietic-type resin acids via stable carbocations

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