Biological Evaluation of the NIR‐Emissive Ruby Analogue [Cr(ddpd)2][BF4]3 as a Photodynamic Therapy Photosensitizer

International audiencePhotodynamic therapy relies on the bioavailability of photosensitizers with suitable photophysical, chemical and biochemical properties. Although the photophysical properties, stability and high water solubility of the chromium(III) complex [Cr(ddpd)2][BF4]3 (ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine) are very favorable, its photocytotoxicity against cancerous and non-cancerous cell lines has not yet been elucidated. We now report the cytotoxicity and photocytotoxicity of the complex [Cr(ddpd)2][BF4]3 against human cervical cancer cells, human primary glioblastoma cells, human glioblastoma astrocytoma cells and non-cancerous retinal pigment epithelium cells

Metallodrug profiling against SARS-CoV-2 target proteins identifies highly potent inhibitors of the S/ACE2 interaction and the papain-like protease PL^pro

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has called for an urgent need for dedicated antiviral therapeutics. Metal complexes are commonly underrepresented in compound libraries that are used for screening in drug discovery campaigns, however, there is growing evidence for their role in medicinal chemistry. Based on previous results, we have selected more than 100 structurally diverse metal complexes for profiling as inhibitors of two relevant SARS-CoV-2 replication mechanisms, namely the interaction of the spike (S) protein with the ACE2 receptor and the papain-like protease PLpro. In addition to many well-established types of mononuclear experimental metallodrugs, the pool of compounds tested was extended to approved metal-based therapeutics such as silver sulfadiazine and thiomersal, as well as polyoxometalates (POMs). Among the mononuclear metal complexes, only a small number of active inhibitors of the S/ACE2 interaction was identified, with titanocene dichloride as the only strong inhibitor. However, among the gold and silver containing complexes many turned out to be very potent inhibitors of PLpro activity. Highly promising activity against both targets was noted for many POMs. Selected complexes were evaluated in antiviral SARS-CoV-2 assays confirming activity for gold complexes with N-heterocyclic carbene (NHC) or dithiocarbamato ligands, a silver NHC complex, titanocene dichloride as well as a POM compound. These studies might provide starting points for the design of metal-based SARS-CoV-2 antiviral agents

Invasion of ovarian cancer cells is induced by PITX2-mediated activation of TGF-β and Activin-A

Background:Most ovarian cancers are highly invasive in nature and the high burden of metastatic disease make them a leading cause of mortality among all gynaecological malignancies. The homeodomain transcription factor, PITX2 is associated with cancer in different tissues. Our previous studies demonstrated increased PITX2 expression in human ovarian tumours. Growing evidence linking activation of TGF-β pathway by homeodomain proteins prompted us to look for the possible involvement of this signalling pathway in PITX2-mediated progression of ovarian cancer. Methods: The status of TGF-β signalling in human ovarian tissues was assessed by immunohistochemistry. The expression level of TGFB/INHBA and other invasion-associated genes was measured by quantitative-PCR (Q-PCR) and Western Blot after transfection/treatments with clones/reagents in normal/cancer cells. The physiological effect of PITX2 on invasion/motility was checked by matrigel invasion and wound healing assay. The PITX2- and activin-induced epithelial-mesenchymal transition (EMT) was evaluated by Q-PCR of respective markers and confocal/phase-contrast imaging of cells. Results: Human ovarian tumours showed enhanced TGF-β signalling. Our study uncovers the PITX2-induced expression of TGFB1/2/3 as well as INHBA genes (p < 0.01) followed by SMAD2/3-dependent TGF-β signalling pathway. PITX2-induced TGF-β pathway regulated the expression of invasion-associated genes, SNAI1, CDH1 and MMP9 (p < 0.01) that accounted for enhanced motility/invasion of ovarian cancers. Snail and MMP9 acted as important mediators of PITX2-induced invasiveness of ovarian cancer cells. PITX2 over-expression resulted in loss of epithelial markers (p < 0.01) and gain of mesenchymal markers (p < 0.01) that contributed significantly to ovarian oncogenesis. PITX2-induced INHBA expression (p < 0.01) contributed to EMT in both normal and ovarian cancer cells. Conclusions: Overall, our findings suggest a significant contributory role of PITX2 in promoting invasive behaviour of ovarian cancer cells through up-regulation of TGFB/INHBA. We have also identified the previously unknown involvement of activin-A in promoting EMT. Our work provides novel mechanistic insights into the invasive behavior of ovarian cancer cells. The extension of this study have the potential for therapeutic applications in future

Interface between 2 dissimilar fluids beneath a sheetpile cofferdam

A closed form solution is presented for determining the shape and location of the interface between two dissimilar fluids (having different densities) when steady flow takes place through a homogeneous and isotropic porous medium, into a sheetpile cofferdam; the interface is assumed to be sharp and the lower fluid stationary. The solution is obtained using the inverse hodograph. Numerical results are presented in nondimensional form for various parametric conditions in the physical plane; the interface pattern, as also the seepage discharge and exit gradient distribution are shown. The critical conditions of the interface are studied

Depressed weir with two unequal sheetpiles in anisotropic soil

An analytical solution is presented, making use of the Schwartz-Christoffel transformation, for determining the seepage characteristics for the problem of flow under a weir having two unequal sheetpiles at the ends and embedded in an anisotropic porous medium of finite thickness. Results for several particular cases of simple hydraulic structures can be obtained from the general solution presented. Numerical results in nondimensional form have been given for quantity of seepage and exit gradient distribution for various conditions in the equivalent transformed isotropic section and, by making use of the physical parameters in the actual anisotropic plane and the set of transformation relations given, these quantities (seepage loss, exit gradient) can be interpreted in the actual anisotropic physical plane

Abstract P07: Inhibition of androgen-regulated TMPRSS2 and lipogenic enzymes in prostate and lung carcinoma cell lines by a cisplatin prodrug

Abstract The main causative agent for the global pandemic of COVID-19 is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Developing therapeutic strategies to stop the virus is the hour of need. According to the recent clinical reports, it is seen that an androgen-regulated host cell serine protease TMPRSS2 acts on the spike protein of the SARS-CoV-2 virus which interacts with the host angiotensin-converting enzyme 2 (ACE2) and enters the host cell to cause the infection. Reports also suggest that TMPRSS2 is regulated by androgen present in prostate cells and it is highly expressed in PCa patients. Our lab has recently synthesized a new cisplatin prodrug which is a conjugate of lauric acid and cisplatin that potentially works very effectively in various androgen dependent and independent prostate cancer (PCa) cells. The cisplatin prodrug unlike other conventional platinum drugs is involved in inhibition of one of the major metabolic pathways of the PCa cells. Preliminary results show that, the prodrug in combination with the anti-androgen bicalutamide has an increased inhibition on the expression of TMPRSS2 in androgen dependent PCa and lung carcinoma cells along with down-regulation of some the lipogenic enzymes in-vitro. Here, we propose that the prodrug inhibits one of the mitochondrial metabolic pathways making the PCa cells sensitive towards cisplatin-based chemotherapy along with reducing the expression of TMPRSS2. Once completed, our work will provide an inside story of cisplatin prodrug mediated alteration of lipogenesis of cells in PCa tumor microenvironment resulting in a platform that has the potential to reduce the burden of cancer aggressiveness in both androgen dependent and independent PCa and also can be used as a potent chemotherapeutic agent against COVID-19. Citation Format: Subham Guin, Bapurao Surnar, Uttara Basu, Shanta Dhar. Inhibition of androgen-regulated TMPRSS2 and lipogenic enzymes in prostate and lung carcinoma cell lines by a cisplatin prodrug [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P07

Solution of a hypersingular integral equation of the second kind

A straightforward analysis involving the complex function-theoretic method is employed to determine the closed-form solution of a special hypersingular integral equation of the second kind, and its known solution is recovered

Migration and maturation pattern of fetal enteric ganglia: A study of 16 cases

Aims: To study the migration and developmental pattern of ganglion cells in fetuses aged 9-21 weeks, and to document whether the migration was occurring circumferentially equally in the entire axis or if there were discrepancies in different portions at the same level. Settings and Design: The hypothesis regarding the pathogenesis of Hirschsprung′s disease mainly revolves around two schools. One is the single gradient migration of ganglia and the other is a dual gradient migration theory. Understanding the embryological development of enteric ganglia is necessary to study the pathogenesis of intestinal innervation disorders. Materials and Methods: We studied the development of intestinal ganglia in fetuses aged 9-21 weeks. Serial longitudinal sections from the colon were studied, the first one including the squamo-columnar junction, for the presence and the nature of ganglion cells with Hematoxylin and Eosin, and neurone-specific enolase immunostaining. Transverse sections from proximal gut were studied in a similar fashion. Thus, we evaluated the migration pattern as well as the nature of ganglia in the fetuses. We also measured the length of distal aganglionic segment in these growing fetuses. Results: We noted that ganglion cells appear first in the myenteric plexus followed by deep and superficial submucous plexus. We also found evidences in favor of dual migration theory, and the distal aganglionic segment varies around the circumference of the rectal wall. Conclusions: We got evidences in support of a dual migration pattern of intestinal ganglion cells. The level of distal aganglionic segments when measured from squamo-columnar junction varied with the age of gestation and the length was incongruous. The description of distal aganglionic segment may help surgeons while taking biopsies or during operative procedures

En plaque meningioma with angioinvasion

En plaque meningioma is a rare type of meningioma characterized by infiltrative nature, sheet-like growth and at times invading the bone. We report here a case of en plaque meningioma with typical grade I histomorphology along with unusual feature of angioinvasion. The patient was a 55-year-old man presenting with headache and painful proptosis of right eye. Imaging modalities revealed an en -plaque meningioma extending into the right sylvian fissure, with thickening of right temporal calvarium, greater wing of sphenoid and extension into the orbit. Magnetic resonance angiography showed medial displacement of right middle cerebral artery. The tumor was removed from the sylvian fissure and right temporal convexity. However, only subtotal removal of the intraorbital part was possible. Histology showed a meningothelial meningioma with low tumor cell proliferation, but infiltration into the bone, skeletal muscle and angioinvasion. Recognition of meningiomas en plaque is useful, as these tumors are difficult to resect completely, and are more prone to undergo recurrence or malignant change. In addition, angioinvasion seen in this tumor may have additional prognostic significance