Design, synthesis and biological evaluation studies of novel small molecule ENPP1 inhibitors for cancer immunotherapy.

Ecto-nucleotide pyrophosphatase/phosphodiesterases 1 (ENPP1 or NPP1), is an attractive therapeutic target for various diseases, primarily cancer and mineralization disorders. The ecto-enzyme is located on the cell surface and has been implicated in the control of extracellular levels of nucleotide, nucleoside and (di) phosphate. Recently, it has emerged as a critical phosphodiesterase that hydrolyzes cyclic 2'3'- cGAMP, the endogenous ligand for STING (STimulator of INterferon Genes). STING plays an important role in innate immunity by activating type I interferon in response to cytosolic 2'3'-cGAMP. ENPP1 negatively regulates the STING pathway and hence its inhibition makes it an attractive therapeutic target for cancer immunotherapy. Herein, we describe the design, optimization and biological evaluation studies of a series of novel non-nucleotidic thioguanine based small molecule inhibitors of ENPP1. The lead compound 43 has shown good in vitro potency, stability in SGF/SIF/PBS, selectivity, ADME properties and pharmacokinetic profile and finally potent anti-tumor response in vivo. These compounds are a good starting point for the development of potentially effective cancer immunotherapy agents.

A prospective longitudinal study to evaluate bone health, implication of FRAX tool and impact on quality of life (FACT-P) in advanced prostate cancer patients.

BACKGROUND: Androgen-deprivation therapy (ADT) as a treatment modality in advanced prostate cancer has deleterious effect on bone mineral density (BMD) and quality of life (QOL). Using FRAX (Fracture Risk Assessment) model, candidates at high risk of fractures can be predicted and appropriate treatment can be initiated at early step to prevent skeletal-related events. Objectives of the present study were to evaluate bone health, implication of FRAX tool in advanced prostate cancer and to see the impact of ADT and Bone-directed therapy (BDT) on FRAX and FACT-P QOL scores. MATERIAL & METHOD: We conducted a prospective longitudinal study of 83 localized and metastatic prostate cancer patients from March 2017 to Dec 2020. FRAX tool using BMD femoral neck (GE-Lunar) was used to compute the probability of 10-year Major osteoporotic fracture (MOF) and hip fracture risk %. Patients who received monthly Zolendronic acid with or without Vitamin-D/calcium supplementation were classified as BDT group. FRAX and FACT-P were measured at baseline and 12 months follow-up and compared between different therapeutic modalities to see the impact on clinical outcomes. RESULTS: Majority of patients had skeletal metastasis (78.3%) and high-grade disease at presentation. Secondary osteoporosis was the most commonly (82.05%) observed clinical risk factor (CRF) followed by smoking (19.23%). Hip fracture risk ≥3% accounted for larger proportion of patients than did MOF risk ≥20% (21.2% and 2.5%, respectively). Statistically significant reduction was observed in both MOF and hip fracture risk in BDT group, while worsening on ADT. ADT duration correlated positively with both MOF and hip fracture risk (R2=0.148, P<0.001 and R2=0.164, P<0.001, respectively). FRAX score accurately predict future fracture events in majority (80%) of high-risk patients. Statistically and clinically significant worsening in PWB, EWB, PCS, FACT-P Total, FACT-P TOI and FAPSI scores were observed in patients on ADT. Statistically and clinically significant improvement was noted in physical well-being in BDT group. However, other QOL domains and FACT-P total scores remained stable. CONCLUSIONS: ADT caused duration depended worsening of FRAX and FACT-P score in these patients while improvements of FRAX were seen on BDT. FRAX tool is advantageous in identifying the patients who require early intervention or therapy to decrease skeletal-related events.

Identification and structure-activity relationship studies of small molecule inhibitors of the human cathepsin D.

Cathepsin D, an aspartyl protease, is an attractive therapeutic target for various diseases, primarily cancer and osteoarthritis. However, despite several small molecule cathepsin D inhibitors being developed, that are highly potent, most of them show poor microsomal stability, which in turn limits their clinical translation. Herein, we describe the design, optimization and evaluation of a series of novel non-peptidic acylguanidine based small molecule inhibitors of cathepsin D. Optimization of our hit compound 1a (IC50 = 29 nM) led to the highly potent mono sulphonamide analogue 4b (IC50 = 4 nM), however with poor microsomal stability (HLM: 177 and MLM: 177 µl/min/mg). To further improve the microsomal stability while retaining the potency, we carried out an extensive structure-activity relationship screen which led to the identification of our optimised lead 24e (IC50 = 45 nM), with an improved microsomal stability (HLM: 59.1 and MLM: 86.8 µl/min/mg). Our efforts reveal that 24e could be a good starting point or potential candidate for further preclinical studies against diseases where Cathepsin D plays an important role.

EUS-guided fine-needle core liver biopsy sampling using a novel 19-gauge needle with modified 1-pass, 1 actuation wet suction technique.

BACKGROUND AND AIMS: EUS-guided fine-needle core biopsy sampling is a safe and effective technique for diagnosis of focal liver lesions. However, data are limited in its role in parenchymal disease. We evaluated the utility of EUS-guided parenchymal liver biopsy sampling with a modified 1-pass wet suction technique (EUS-modified liver biopsy sampling [EUS-MLB]) in patients with unexplained increase in liver-associated tests. METHODS: We retrospectively evaluated the safety and efficacy of EUS-MLB in patients referred for EUS to evaluate for biliary obstruction and pancreatic disorders but with associated unexplained liver tests. EUS-MLB was performed during the same session after biliary obstruction was excluded. RESULTS: One hundred sixty-five consecutive patients underwent EUS-MLB. The median age was 52 years (interquartile range [IQR], 42-65). Sixty-eight patients (41%) were men. The median of the maximum intact core tissue length was 2.4 cm (IQR, 1.8-3.5). The median total specimen length (TSL) was 6 cm (IQR, 4.3-8). The median number of complete portal tracts (CPTs) per TSL was 18 (IQR, 13- 24). The mean number of CPTs per sample length was 7.5 cm. Adverse events were uncommon (1.8%) and included abdominal pain and self-limited hematoma. CONCLUSIONS: EUS-guided fine-needle biopsy sampling using a novel 19-gauge core needle with a modified 1-pass 1 actuation wet suction technique (EUS-MLB) is a safe and effective way to evaluate patients with unexplained liver tests abnormalities who are undergoing EUS for exclusion of biliary obstruction.

Metachronous bilateral segmental testicular infarction: multi-parametric ultrasound imaging with grey-scale ultrasound, Doppler ultrasound, contrast-enhanced ultrasound (CEUS) and real-time tissue elastography (RTE).

Segmental testicular infarction is a rare cause of acute scrotal pain. The appearances on grey-scale sonography are often indistinguishable from that of a testicular tumour, resulting in unnecessary orchiectomy. We report a case of acute bilateral testicular infarction, of unknown etiology, which was conservatively managed to resolution following a confident diagnosis achieved with the aid of contrast-enhanced ultrasound (CEUS) and real-time tissue elastography (RTE) along with conventional grey-scale and Doppler sonography. The evolving appearances on each of the sonographic modalities are described. We discuss the importance of complementing conventional sonography with CEUS and RTE in order to make a confident diagnosis and avoid unnecessary surgical intervention.

Features of testicular epidermoid cysts on contrast-enhanced sonography and real-time tissue elastography.

A series of 7 testicular epidermoid cysts were imaged by contrast-enhanced sonography to assess internal vascularity and by real-time tissue elastography to grade stiffness by a visual and strain ratio quantification scoring system. No internal vascular enhancement was seen on contrast-enhanced sonography; the 3 largest lesions showed rim enhancement. On the real-time elastographic color display, all lesions were predominantly blue ("hard"), and the lesions analyzed for the strain ratio had a mean value of 43.57. Contrast-enhanced sonography depicts the absence of vascular flow, and real-time elastography shows that the epidermoid cysts are hard. This combination of information will help further characterize these lesions.

Vincristine-sulphate-loaded liposome-templated calcium phosphate nanoshell as potential tumor-targeting delivery system.

Vincristine-sulfate-loaded liposomes were prepared with an aim to improve stability, reduce drug leakage during systemic circulation, and increase intracellular uptake. Liposomes were prepared by the thin-film hydration method, followed by coating with calcium phosphate, using the sequential addition approach. Prepared formulations were characterized for size, zeta potential, drug-entrapment efficiency, morphology by transmission electron microscopy (TEM), in vitro drug-release profile, and in vitro cell cytotoxicity study. Effect of formulation variables, such as drug:lipid ratio as well as nature and volume of hydration media, were found to affect drug entrapment, and the concentration of calcium chloride in coating was found to affect size and coating efficiency. Size, zeta potential, and TEM images confirmed that the liposomes were effectively coated with calcium phosphate. The calcium phosphate nanoshell exhibited pH-dependent drug release, showing significantly lower release at pH 7.4, compared to the release at pH 4.5, which is the pH of the tumor interstitium. The in vitro cytotoxicity study done on the lung cancer cell line indicated that coated liposomes are more cytotoxic than plain liposomes and drug solution, indicating their potential for intracellular drug delivery. The cell-uptake study done on the lung cancer cell line indicated that calcium-phosphate-coated liposomes show higher cell uptake than uncoated liposomes.