Endogenous PP2A inhibitor CIP2A degradation by chaperone-mediated autophagy contributes to the antitumor effect of mitochondrial complex I inhibition

Combined inhibition of oxidative phosphorylation (OXPHOS) and glycolysis has been shown to activate a PP2A-dependent signaling pathway, leading to tumor cell death. Here, we analyze highly selective mitochondrial complex I or III inhibitors in vitro and in vivo to elucidate the molecular mechanisms leading to cell death following OXPHOS inhibition. We show that IACS-010759 treatment (complex I inhibitor) induces a reactive oxygen species (ROS)-dependent dissociation of CIP2A from PP2A, leading to its destabilization and degradation through chaperone-mediated autophagy. Mitochondrial complex III inhibition has analogous effects. We establish that activation of the PP2A holoenzyme containing B56δ regulatory subunit selectively mediates tumor cell death, while the arrest in proliferation that is observed upon IACS-010759 treatment does not depend on the PP2A-B56δ complex. These studies provide a molecular characterization of the events subsequent to the alteration of critical bioenergetic pathways and help to refine clinical studies aimed to exploit metabolic vulnerabilities of tumor cells.

Clinical effectiveness of a new oral curcumin formulation in acute non-infectious uveitic macular edema: a 12-month observational study

OBJECTIVE

Oral supplementation with curcumin demonstrated a beneficial effect on some ocular diseases, including uveitis and macular edema. This study aimed to evaluate the effectiveness and safety of a curcumin formulation with the hydrophilic carrier (CHC; Diabec®, Alfa Intes, Italy) as an adjuvant to standard steroid treatment in adults suffering from acute non-infectious uveitic macular edema (NIUME).

PATIENTS AND METHODS

This was a monocenter prospective observational study carried out between January 2019 and May 2020 on consecutive patients with a new diagnosis of NIUME. Patients were treated with standard therapy or with a CHC add-on to standard treatment. The observation period for each patient was 12 months. The Best Corrected Visual Acuity (BCVA) and the Central Macular Thickness (CMT) were the primary outcomes; Foveal Avascular Zone (FAZ) and intraocular pressure (IOP) were also assessed, along with safety data.

RESULTS

A total of 43 eyes of 26 patients were analyzed. CHC-treated eyes showed an improvement in mean BCVA from baseline (0.34 logMar) to T6 (0.20 logMar) and T12 (0.19 logMar; p≤0.05 and p≤0.01, respectively); CMT decreased from a mean of 320 μm (T0) to 278 μm (T6; p≤0.05) and 272 μm (T12; p≤0.01). A significant improvement of mean BCVA in the CHC group at T6 and T12 was reported compared to the control group (p≤0.01). FAZ and IOP showed no statistically significant variations in both groups. No adverse events were recorded.

CONCLUSIONS

CHC as an adjuvant treatment improved the anatomical and functional outcomes, without significant side effects in eyes affected by the recent onset of NIUME, compared to the sole standard therapy.

Synthetic Lethality in Pancreatic Cancer: Discovery of a New RAD51-BRCA2 Small Molecule Disruptor That Inhibits Homologous Recombination and Synergizes with Olaparib

Synthetic lethality is an innovative framework for discovering novel anticancer drug candidates. One example is the use of PARP inhibitors (PARPi) in oncology patients with BRCA mutations. Here, we exploit a new paradigm based on the possibility of triggering synthetic lethality using only small organic molecules (dubbed “fully small-molecule-induced synthetic lethality”). We exploited this paradigm to target pancreatic cancer, one of the major unmet needs in oncology. We discovered a dihydroquinolone pyrazoline-based molecule (35d) that disrupts the RAD51-BRCA2 protein–protein interaction, thus mimicking the effect of BRCA2 mutation. 35d inhibits the homologous recombination in a human pancreatic adenocarcinoma cell line. In addition, it synergizes with olaparib (a PARPi) to trigger synthetic lethality. This strategy aims to widen the use of PARPi in BRCA-competent and olaparib-resistant cancers, making fully small-molecule-induced synthetic lethality an innovative approach toward unmet oncological needs.

The challenge of cholestatic pruritus

Pruritus can be the dominant symptom of cholestatic liver disease but is difficult to treat since unraveling its pathophysiology is a great challenge. Serum autotaxin activity correlates with pruritus intensity, but its causal relationship, expression pattern and exact mode of action during cholestasis remain to be established. The anion exchange resin cholestyramine, the PXR agonist rifampicin, the opioid antagonist naltrexone and the serotonine reuptake inhibitor sertraline are recommended by evidence-based guidelines as stepwise therapeutic approaches to treat itch in cholestasis. Rifampicin, the most effective antipruritic agent in cholestatic itch, has been shown to reduce autotaxin transcription in vitro. Experimental approaches include UVB phototherapy, extracorporeal albumin dialysis, nasobiliary drainage and in desperate cases even liver transplantation. Relevant clinical observations along with the different metabolic, neurologic and endocrine targets of available therapies in cholestatic pruritus are reviewed here.

Metal and metallothionein content in tissues from wild and farmed Anguilla anguilla at commercial size

Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel (Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones. No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in muscle and in all instances these levels were lower than the limits established by the Spanish legislation for fish destined for human consumption.

Overexpression of a member of the pentraxin family (PTX3) in human soft tissue liposarcoma

A unique feature of human soft tissue liposarcoma is a stable (12;16)(q13;p11) translocation observed mainly in myxoid and roundcell liposarcomas. This translocation results in FUS/CHOP fusion transcripts with a corresponding oncogenic protein. We hypothesised that genes downstream of FUS/CHOP might serve as attractive candidates for novel tumour associated antigens. Among a panel of analysed genes, only pentraxin related gene (PTX3) demonstrated high expression in liposarcomas as compared to normal tissues. The analysis of RNA and protein expression demonstrated concordant results. However, the level of RNA and protein overexpression did not correlate in all cases. Finally, PTX3 expression was not related to presence of a FUS/CHOP fusion transcript within the liposarcoma tissues. PTX3 has been associated with adipocyte differentiation and now, additionally, is characterised by a markedly increased expression in human soft tissue liposarcoma. This finding mandates further research efforts to clarify the exact role of PTX3 in liposarcoma oncogenesis.

A review of trends in new case-detection in Subarnapur district of Orissa

Trends in new case-detection are analysed by reviewing the demographic and leprosy epidemiological data and current indicators in Subarnapur district, Orissa State and India. Population-specific new case-detection rates were calculated for analysis. The trend of skin-smear positive cases over a period of 10 years was reviewed in respect of smear positive cases of 1991. During the years 2002 to 2004, a sudden fall was noticed in the new cases detected in both India and Orissa state, whereas the decline in Subarnapur district was more gradual. The fall in the female-specific new case-detection rates is found to be rapid from 11 to 2.5 over the last three years. This also indirectly indicated the health-seeking behaviour of women in accessing health services and hence required a changed strategy. A similar rapid decline was observed in child-specific new case-detection rates. On analysiS, the decline of highly bacilliferous cases from 1991 to 2001 was found to be statistically significant. The analysis also brought out the fact that cases with bacterial index of 1+, 2+ and 3+, though small in numbers, were detected during the last three years indicating continued presence of cases with low bacterial density in the community. The review indicates a definite decline in the occurrence of new cases in all groups. Caution needs to be exercised about continued presence of cases with low bacterial index though in small numbers. The rapid decrease of cases in all groups during the years 2004 and 2005 warrants meticulous surveillance. The surveillance activities could include monitoring of population-specific new case-detection rates and skin-smear positive cases at district and state levels in order to advise on leprosy eradication programme strategies.

A reassessment of the translation initiation codon in vertebrates

More than two decades ago Marilyn Kozak proposed the scanning model of translation initiation, whereby translation is initiated at the first AUG codon that is in a particular context. In this article, we re-examine the context of initiator codons using a large dataset of curated human transcripts. We find that more than 40% of transcripts contain AUG codons upstream of the actual start codon and that most authentic AUGs contain three or more mismatches from the consensus sequence, CCACCaugG. Also, in a large fraction of transcripts, the sequences surrounding the initiator codon deviate more from the consensus than those surrounding upstream AUGs, indicating that translation initiation from downstream AUGs is more common than generally believed.

GPMAW--a software tool for analyzing proteins and peptides

General Protein/Mass Analysis for Windows (GPMAW) is a valuable piece of software for any molecular biologist, biochemist or mass spectrometrist wishing to analyze protein or peptide sequences. All steps from the acquisition of protein sequence from a built-in web interface, to proteolytic digests, theoretical peptide fragmentation, detailed annotation of sequences and secondary structure prediction, can be performed rapidly and intuitively without first having to spend days reading manuals.

Profiles from structure based sequence alignment of porins can identify beta stranded integral membrane proteins

Supplementary information: http://gene.tn.nic.in/sk/profiles/

Contact: krishna@mrna.tn.nic.in

To whom correspondence should be addressed.

Peak expiratory flow rate in South Indian adults

Peak Expiratory Flow Rate (PEFR) was measured with a Wright Peak Flow Meter in 851 healthy men and women of two categories; Group I--students and staff of the Medical College constituting the middle income group, and Group II--healthy individuals from the poorer class with an income of less than Rs.200/-per month, forming the lower income group. In both categories women had much lower values than men, and in both sexes the values in the subjects of the poor income group was significantly lower. The PEFR was found to correlate best with height in subjects below 30 years, and with age in older subjects. The mean values, standard deviations and regression equations are given for the different groups. Present values are also compared with some western and Indian data.