Global and Regional Effects of Bladder Cancer Risk Associated with Pioglitazone Therapy in Patients with Diabetes

4D Printing for Biomedical Applications

4D (bio-)printing endows 3D printed (bio-)materials with multiple functionalities and dynamic properties. 4D printed materials have been recently used in biomedical engineering for the design and fabrication of biomedical devices, such as stents, occluders, microneedles, smart 3D-cell engineered microenvironments, drug delivery systems, wound closures, and implantable medical devices. However, the success of 4D printing relies on the rational design of 4D printed objects, the selection of smart materials, and the availability of appropriate types of external (multi-)stimuli. Here, this work first highlights the different types of smart materials, external stimuli, and design strategies used in 4D (bio-)printing. Then, it presents a critical review of the biomedical applications of 4D printing and discusses the future directions of biomedical research in this exciting area, including in vivo tissue regeneration studies, the implementation of multiple materials with reversible shape memory behaviors, the creation of fast shape-transformation responses, the ability to operate at the microscale, untethered activation and control, and the application of (machine learning-based) modeling approaches to predict the structure-property and design-shape transformation relationships of 4D (bio)printed constructs.

Genetically proxied glucose-lowering drug target perturbation and risk of cancer: a Mendelian randomisation analysis

AIMS/HYPOTHESIS

Epidemiological studies have generated conflicting findings on the relationship between glucose-lowering medication use and cancer risk. Naturally occurring variation in genes encoding glucose-lowering drug targets can be used to investigate the effect of their pharmacological perturbation on cancer risk.

METHODS

We developed genetic instruments for three glucose-lowering drug targets (peroxisome proliferator activated receptor γ [PPARG]; sulfonylurea receptor 1 [ATP binding cassette subfamily C member 8 (ABCC8)]; glucagon-like peptide 1 receptor [GLP1R]) using summary genetic association data from a genome-wide association study of type 2 diabetes in 148,726 cases and 965,732 controls in the Million Veteran Program. Genetic instruments were constructed using cis-acting genome-wide significant (p<5×10-8) SNPs permitted to be in weak linkage disequilibrium (r2<0.20). Summary genetic association estimates for these SNPs were obtained from genome-wide association study (GWAS) consortia for the following cancers: breast (122,977 cases, 105,974 controls); colorectal (58,221 cases, 67,694 controls); prostate (79,148 cases, 61,106 controls); and overall (i.e. site-combined) cancer (27,483 cases, 372,016 controls). Inverse-variance weighted random-effects models adjusting for linkage disequilibrium were employed to estimate causal associations between genetically proxied drug target perturbation and cancer risk. Co-localisation analysis was employed to examine robustness of findings to violations of Mendelian randomisation (MR) assumptions. A Bonferroni correction was employed as a heuristic to define associations from MR analyses as 'strong' and 'weak' evidence.

RESULTS

In MR analysis, genetically proxied PPARG perturbation was weakly associated with higher risk of prostate cancer (for PPARG perturbation equivalent to a 1 unit decrease in inverse rank normal transformed HbA1c: OR 1.75 [95% CI 1.07, 2.85], p=0.02). In histological subtype-stratified analyses, genetically proxied PPARG perturbation was weakly associated with lower risk of oestrogen receptor-positive breast cancer (OR 0.57 [95% CI 0.38, 0.85], p=6.45×10-3). In co-localisation analysis, however, there was little evidence of shared causal variants for type 2 diabetes liability and cancer endpoints in the PPARG locus, although these analyses were likely underpowered. There was little evidence to support associations between genetically proxied PPARG perturbation and colorectal or overall cancer risk or between genetically proxied ABCC8 or GLP1R perturbation with risk across cancer endpoints.

CONCLUSIONS/INTERPRETATION

Our drug target MR analyses did not find consistent evidence to support an association of genetically proxied PPARG, ABCC8 or GLP1R perturbation with breast, colorectal, prostate or overall cancer risk. Further evaluation of these drug targets using alternative molecular epidemiological approaches may help to further corroborate the findings presented in this analysis.

DATA AVAILABILITY

Summary genetic association data for select cancer endpoints were obtained from the public domain: breast cancer ( https://bcac.ccge.medschl.cam.ac.uk/bcacdata/ ); and overall prostate cancer ( http://practical.icr.ac.uk/blog/ ). Summary genetic association data for colorectal cancer can be accessed by contacting GECCO (kafdem at fredhutch.org). Summary genetic association data on advanced prostate cancer can be accessed by contacting PRACTICAL (practical at icr.ac.uk). Summary genetic association data on type 2 diabetes from Vujkovic et al (Nat Genet, 2020) can be accessed through dbGAP under accession number phs001672.v3.p1 (pha004945.1 refers to the European-specific summary statistics). UK Biobank data can be accessed by registering with UK Biobank and completing the registration form in the Access Management System (AMS) ( https://www.ukbiobank.ac.uk/enable-your-research/apply-for-access ).

Pioglitazone, Bladder Cancer and the Presumption of Innocence

BACKGROUND

Thiazolidinediones are potent exogenous agonists of PPAR-γ, which augment the effects of insulin to its cellular targets and mainly at the level of adipose tissue. Pioglitazone, the main thiazolidinedione in clinical practice, has shown cardiovascular and renal benefits in patients with type 2 diabetes, durable reduction of glycated hemoglobulin levels, important improvements of several components of the metabolic syndrome and beneficial effects of non-alcoholic fatty liver disease.

OBJECTIVE

Despite all of its established advantages, the controversy for an increased risk of developing bladder cancer, combined with the advent of newer drug classes that achieved major cardiorenal effects have significantly limited its use spreading a persistent shadow of doubt for its future role.

METHODS

Pubmed, Google and Scope databases have been thoroughly searched and relevant studies were selected.

RESULTS

This paper explores thoroughly both in vitro and in vivo (animal models and humans) studies that investigated the possible association of pioglitazone with bladder cancer.

CONCLUSION

Currently the association of pioglitazone with bladder cancer cannot be based on solid evidence. This evidence cannot justify its low clinical administration, especially in the present era of individualised treatment strategies. Definite clarification of this issue is imperative and urgently anticipated from future high quality and rigorous pharmacoepidemiologic research, keeping in mind its unique mechanism of action and its significant pleiotropic effects.

The red flower wintersweet genome provides insights into the evolution of magnoliids and the molecular mechanism for tepal color development

Wintersweet (Chimonanthus praecox) is one of the most important ornamental plants. Its color is mainly determined by the middle tepals. However, the molecular mechanisms underlying the intriguing flower color development among different wintersweet groups are still largely unknown. In addition, wintersweet belongs to magnoliids, and the phylogenetic position of magnoliids remains to be determined conclusively. Here, the whole genome of red flower wintersweet, a new wintersweet type, was sequenced and assembled with high quality. The genome comprised 11 super-scaffolds (chromosomes) with a total size of 737.03 Mb. Based on the analyses of the long branch attraction, incomplete lineage sorting, sparse taxon sampling, and other factors, we suggest that a bifurcating tree may not fully represent the complex early diversification of the angiosperms and that magnoliids are most likely sister to the eudicots. The wintersweet genome appears to have undergone two whole-genome duplication (WGD) events: a recent WGD event representing an independent event specific to the Calycanthaceae and an ancient WGD event shared by Laurales. By integrating genomic, transcriptomic, and metabolomic data, CpANS1 and the transcription factor CpMYB1 were found to play key roles in regulating tepal color development, whereas CpMYB1 needs to form a complex with bHLH and WD40 to fully perform its regulatory function. The present study not only provides novel insights into the evolution of magnoliids and the molecular mechanism for flower color development, but also lays the foundation for subsequent functional genomics study and molecular breeding of wintersweet.

PPARs and Tumor Microenvironment: The Emerging Roles of the Metabolic Master Regulators in Tumor Stromal-Epithelial Crosstalk and Carcinogenesis

Peroxisome proliferator-activated receptors (PPARs) have been extensively studied for more than three decades. Consisting of three isotypes, PPARα, γ, and β/δ, these nuclear receptors are regarded as the master metabolic regulators which govern many aspects of the body energy homeostasis and cell fate. Their roles in malignancy are also increasingly recognized. With the growing interest in crosstalk between tumor stroma and epithelium, this review aims to highlight the current knowledge on the implications of PPARs in the tumor microenvironment. PPARγ plays a crucial role in the metabolic reprogramming of cancer-associated fibroblasts and adipocytes, coercing the two stromal cells to become substrate donors for cancer growth. Fibroblast PPARβ/δ can modify the risk of tumor initiation and cancer susceptibility. In endothelial cells, PPARβ/δ and PPARα are pro- and anti-angiogenic, respectively. Although the angiogenic role of PPARγ remains ambiguous, it is a crucial regulator in autocrine and paracrine signaling of cancer-associated fibroblasts and tumor-associated macrophages/immune cells. Of note, angiopoietin-like 4 (ANGPTL4), a secretory protein encoded by a target gene of PPARs, triggers critical oncogenic processes such as inflammatory signaling, extracellular matrix derangement, anoikis resistance and metastasis, making it a potential drug target for cancer treatment. To conclude, PPARs in the tumor microenvironment exhibit oncogenic activities which are highly controversial and dependent on many factors such as stromal cell types, cancer types, and oncogenesis stages. Thus, the success of PPAR-based anticancer treatment potentially relies on innovative strategies to modulate PPAR activity in a cell type-specific manner.

Insulin-Like Growth Factor-1-Loaded Polymeric Poly(Lactic-Co-Glycolic) Acid Microspheres Improved Erectile Function in a Rat Model of Bilateral Cavernous Nerve Injury

BACKGROUND

Previous studies have documented improvement in erectile function after bilateral cavernous nerve injury (BCNI) in rats with the use of pioglitazone. Our group determined this improvement to be mediated by the insulin-like growth factor-1 (IGF-1) pathway.

AIM

To eliminate the systemic effects of pioglitazone and evaluate the local delivery of IGF-1 by polymeric microspheres after BCNI in the rat.

METHODS

Male Sprague-Dawley rats aged 10-12 weeks were assigned at random to 3 groups: sham operation with phosphate buffered saline (PBS)-loaded microspheres (sham group), crush injury with PBS-loaded microspheres (crush group), and crush injury with IGF-1-loaded microspheres (IGF-1 group). Poly(lactic-co-glycolic) acid microspheres were injected underneath the major pelvic ganglion (MPG). IGF-1 was released at approximately 30 ng/mL/day per MPG per rat.

OUTCOMES

Functional results were demonstrated by maximal intracavernosal pressure (ICP) normalized to mean arterial pressure (MAP). Protein-level analysis data of IGF-1 receptor (IGF-1R), extracellular signal-regulated kinase (ERK)-1/2, and neuronal nitric oxide synthase (nNOS) were obtained using Western blot analysis and immunohistochemistry for both the cavernosal tissue and the MPG and cavernous nerve (CN).

RESULTS

At 2 weeks after nerve injury, animals treated with IGF-1 demonstrated improved erectile functional recovery (ICP/MAP) at all voltages compared with BCNI (2.5V, P = .001; 5V, P < .001; 7.5V, P < .001). Western blot results revealed that up-regulation of the IGF-1R and ERK-1/2 in both the nervous and erectile tissue was associated with improved erectile function recovery. There were no significant between-group differences in nNOS protein levels in cavernosal tissue, but there was an up-regulation of nNOS in the MPG and CN. Immunohistochemistry confirmed these trends.

CLINICAL TRANSLATION

Local up-regulation of the IGF-1R in the neurovascular bed at the time of nerve injury may help men preserve erectile function after pelvic surgery, such as radical prostatectomy, eliminating the need for systemic therapy.

STRENGTHS & LIMITATIONS

This study demonstrates that local drug delivery to the MPG and CN can affect the CN tissue downstream, but did not investigate the potential effects of up-regulation of the growth factor receptors on prostate cancer tissue.

CONCLUSION

Stimulating the IGF-1R at the level of the CN has the potential to mitigate erectile dysfunction in men after radical prostatectomy, but further research is needed to evaluate the safety of this growth factor in the setting of prostate cancer. Haney NM, Talwar S, Akula PK, et al. Insulin-Like Growth Factor-1-Loaded Polymeric Poly(Lactic-Co-Glycolic) Acid Microspheres Improved Erectile Function in a Rat Model of Bilateral Cavernous Nerve Injury. J Sex Med 2019;16:383-393.

More recent, better designed studies have weakened links between antidiabetes medications and cancer risk

BACKGROUND

An increasing number of studies have investigated associations of antidiabetes medications with cancer risk. Antidiabetes medications are classified by their mechanisms of action on tissues and organs. They potentially act as both causative and confounding factors in the temporal association of diabetes and cancer.

AIM

To present the current evidence regarding both the carcinogenic and anti-carcinogenic effects of antidiabetes medications on cancer in humans.

METHODS

A review of the scientific literature.

RESULTS

The most conclusive evidence shown of an association of antidiabetes medication with a specific cancer was for that of the thiazolidinedione pioglitazone with bladder cancer. Currently, there is inconclusive evidence regarding a possible association of incretin therapies, drugs of the dipeptidyl peptidase-4 inhibitor class, with the risk of pancreatic cancer. Insulin, sulfonylureas, metformin and sodium-glucose co-transporter-2 inhibitors appear not to be associated with increased risk of any cancer. Sparse evidence suggests possible protective effects against cancer incidence of metformin, sulfonylureas, thiazolidinediones, incretin-based drugs and sodium-glucose co-transporter-2 inhibitors.

CONCLUSION

The conflicting evidence regarding associations of antidiabetes medications with cancer risk is apparently attributable to both methodological issues and to the complexity of the subject. More recent and better-designed studies have weakened the evidence for links between antidiabetes medications and cancer risk.

Recommendations for Management and Treatment of Nonalcoholic Steatohepatitis

The prevalence of nonalcoholic liver disease (NAFLD) is increasing worldwide in conjunction with the epidemic increase in obesity and metabolic risk factors. Consequently, NAFLD has become a leading indication for liver transplantation. Although genetic factors play an important role in the pathogenesis of NAFLD, detrimental lifestyle trends favoring a calorically unrestricted diet rich in carbohydrates and unsaturated fat, prolonged sedentary periods or limited physical activity have major metabolic implications. In aggregate these physiological dysregulations constitute the main risk factors for the metabolic syndrome and NAFLD. The cornerstone of the treatment of NAFLD, is lifestyle changes, including modifications to diet and physical activity, to reduce body weight and liver fat, however adherence is notoriously poor and the epidemic of NAFLD continues to grow unimpeded. In the face of this unmet clinical need, the pharmacologic therapy of NAFLD has been expanding as the varied mechanistic pathways of NAFLD are elucidated. Beyond these approaches to treating NAFLD, the prevention of other liver diseases is additionally important. Chief among these is alcoholic liver disease, and heavy use is detrimental irrespective of underlying NAFLD. However, the impact of mild to moderate alcohol use in patients with mild or nonadvanced forms NAFLD is undefined. This article summarizes the results of the International Liver Transplantation Society consensus meeting on NAFLD in liver transplantation. It describes the available evidence and provides consensus guidance on the lifestyle and pharmacologic therapies of NAFLD, and the consensus position on alcohol use in patients with NAFLD.

Association of Pioglitazone with Increased Risk of Prostate Cancer and Pancreatic Cancer: A Functional Network Study

INTRODUCTION

The question of whether pioglitazone, an antidiabetic drug, increases the risk of cancer has been debated for some time. Recent studies have shown that pioglitazone use can increase the risk of prostate cancer as well as pancreatic cancer. However, it is unclear whether pioglitazone is a causal risk factor for these cancers.

METHODS

In this study, we aimed to explore the direct targets of pioglitazone and genes associated with this drug by querying open platforms in order to construct a biological function network, and then to further evaluate the relationships of pioglitazone with prostate cancer and pancreatic cancer.

RESULTS

We first tested our hypothesis using DrugBank and STRING. We identified four direct targets of pioglitazone and 50 pioglitazone-associated genes, which were then selected for KEGG pathway analysis using STRING and WebGestalt. This analysis generated the top 25 KEGG pathways, among which four pathways were related to site-specific cancers, including prostate cancer and pancreatic cancer. Finally, a genomic study using cBioPortal indicated that genomic alterations of two gene sets related to the prostate cancer and pancreatic cancer pathways, respectively, are associated with the acceleration of carcinogenesis.

CONCLUSIONS

Pioglitazone is likely to be a causal risk factor for prostate cancer and pancreatic cancer, so this drug should be used with caution. The present research also demonstrates the use of biological function network analysis to effectively explore drug interactions and drug safety profiles.