Novel, isoform-selective, cholecystokinin A receptor antagonist inhibits colon and pancreatic cancers in preclinical models through novel mechanism of action

Colon and pancreatic cancers contribute to 90,000 deaths each year in the USA. These cancers lack targeted therapeutics due to heterogeneity of the disease and multiple causative factors. One important factor that contributes to increased colon and pancreatic cancer risk is gastrin. Gastrin mediates its actions through two G-protein coupled receptors (GPCRs): cholecystokinin receptor A (CCK-A) and CCK-B/gastrin receptor. Previous studies have indicated that colon cancer predominantly expresses CCK-A and responds to CCK-A isoform antagonists. However, many CCK-A antagonists have failed in the clinic due to poor pharmacokinetic properties or lack of efficacy. In the present study, we synthesized a library of CCK-A isoform-selective antagonists and tested them in various colon and pancreatic cancer preclinical models. The lead CCK-A isoform, selective antagonist PNB-028, bound to CCK-A at 12 nM with a 60-fold selectivity towards CCK-A over CCK-B. Furthermore, it inhibited the proliferation of CCK-A-expressing colon and pancreatic cancer cells without affecting the proliferation of non-cancerous cells. PNB-028 was also extremely effective in inhibiting the growth of MAC-16 and LoVo colon cancer and MIA PaCa pancreatic cancer xenografts in immune-compromised mice. Genomewide microarray and kinase-array studies indicate that PNB-028 inhibited oncogenic kinases and angiogenic factors to inhibit the growth of colon cancer xenografts. Safety pharmacology and toxicology studies have indicated that PNB-028 is extremely safe and has a wide safety margin. These studies suggest that targeting CCK-A selectively renders promise to treat colon and pancreatic cancers and that PNB-028 could become the next-generation treatment option.

Paradoxical decrease in HDL-cholesterol and apolipoprotein A1 with simvastatin and atorvastatin in a patient with type 2 diabetes

Statins are agents widely used to lower LDL-cholesterol (LDL-C) in primary and secondary prevention of coronary heart disease. The five statins available in the UK (simvastatin, pravastatin, fluvastatin, atorvastatin and rosuvastatin) differ in many of their pharmacologic properties. In addition to lowering LDL-C, statins also increase HDL-cholesterol (HDL-C) moderately. There have been rare reports of significant HDL-C decreases in patients commenced on fibrates and when thiazolidinediones are added to fibrates. This is known as a 'paradoxical HDL-C decrease' as both groups of agents usually increase HDL-C. This phenomenon has never been clearly documented following statin therapy. We now describe a patient with type 2 diabetes who showed this paradoxical fall in HDL-C (baseline HDL-C: 1.8 mmol/L; on simvastatin 40 mg HDL-C 0.6 mmol/L; on atorvastatin 20 mg HDL-C 0.9 mmol/L) with a similar decrease in apolipoprotein A1. No similar decrease was observed with pravastatin and rosuvastatin therapy. This phenomenon appeared to be associated with statin treatment and not a statin/fibrate combination. Our patient clearly demonstrated a paradoxical HDL-C fall with simvastatin and atorvastatin, but not pravastatin or rosuvastatin. Simvastatin and atorvastatin share many pharmacokinetic properties such as lipophilicity while pravastatin and rosuvastatin are relatively hydrophilic and are not metabolized by cytochrome P450 3A4. However, these characteristics do not explain the dramatic reductions in HDL-C observed.

How education should link with career paths

How good is your pharmacy practice? And what does “good” look like? Take a look back at the education and training you have received in your career to date. Has it stood you in good stead? Certainly there is a need to establish a model of professional education and development that produces good pharmacists — you should be able to demonstrate your competence regardless of your sector of work. It may help if we move away from the view that excellence in pharmacy practice is primarily defined by where you practise and the kind of job that you do. The Modernising Pharmacy Careers programme’s aspirations to integrate the undergraduate degree with the preregistration training year are bold and to be applauded — provided the outcome delivers changes that are more than superficial. The new model needs to deliver greater integration of education with practice, while retaining an adequate science base. Theory should be put into the context of practice-based, cross-sector learning needs and opportunities. For example, is the classroom really the best environment in which to learn dispensing? Pharmacokinetic theory could be put into context through creatively designed work placements. And it might make more sense to learn patient counselling in a community pharmacy, and so on. Is it resources we lack to make this happen? Or do we lack the collective will to be imaginative, to be radical and to conceive new approaches to professional education? Implicit in this new approach to education is the expectation that pharmacists should teach and mentor and, conversely, that those who teach should also engage in relevant practice. University education must produce graduates whose knowledge and competence are useful to employers. Moreover, graduates must be adequately prepared to enter any area of the profession endowed with professional self-confidence (something, arguably, that needs further development within the pharmacy psyche). Of course, becoming qualified is just the beginning. Post-qualification, pharmacists need structured career paths that foster this professional confidence, support learning and ensure recognition. To this end, the Royal Pharmaceutical Society-led professional curriculum group is working to define knowledge, skills and experience for all areas of advanced practice. More than ever, the profession needs to adopt a culture of learning, teaching and practice research that is unified. The question is: how do we move away from merely collecting qualifications (trophies) to developing meaningful careers? Pharmacists in all areas and at all levels of the profession need to consider their own willingness to make this shift. The RPS and MPC are leading the way, but are we following?