An alternatively spliced PD-L1 isoform PD-L1∆3, and PD-L2 expression in breast cancers: implications for eligibility scoring and immunotherapy response.

Targeting PD-1/PD-L1 has shown substantial therapeutic response and unprecedented long-term durable responses in the clinic. However, several challenges persist, encompassing the prediction of treatment effectiveness and patient responses, the emergence of treatment resistance, and the necessity for additional biomarkers. Consequently, we comprehensively explored the often-overlooked isoforms of crucial immunotherapy players, leveraging transcriptomic analysis, structural modeling, and immunohistochemistry (IHC) data. Our investigation has led to the identification of an alternatively spliced isoform of PD-L1 that lacks exon 3 (PD-L1∆3) and the IgV domain required to interact with PD-1. PD-L1∆3 is expressed more than the canonical isoform in a subset of breast cancers and other TCGA tumors. Using the deep learning-based protein modeling tool AlphaFold2, we show the lack of a possible interaction between PD-L1∆3 and PD-1. In addition, we present data on the expression of an additional ligand for PD-1, PD-L2. PD-L2 expression is widespread and positively correlates with PD-L1 levels in breast and other tumors. We report enriched epithelial-mesenchymal transition (EMT) signature in high PD-L2 transcript expressing (PD-L2 > PD-L1) tumors in all breast cancer subtypes, highlighting potential crosstalk between EMT and immune evasion. Notably, the estrogen gene signature is downregulated in ER + breast tumors with high PD-L2. The data on PD-L2 IHC positivity but PD-L1 negativity in breast tumors, together with our results on PD-L1∆3, highlight the need to utilize PD-L2 and PD-L1 isoform-specific antibodies for staining patient tissue sections to offer a more precise prediction of the outcomes of PD-1/PD-L1 immunotherapy.

Mdm2 Snp309 G allele displays high frequency and inverse correlation with somatic P53 mutations in hepatocellular carcinoma.

Loss of function of the p53 protein, which may occur through a range of molecular events, is critical in hepatocellular carcinoma (HCC) evolution. MDM2, an oncogene, acts as a major regulator of the p53 protein. A polymorphism in the MDM2 promoter, SNP309 (T/G), has been shown to alter protein expression and may thus play a role in carcinogenesis. MDM2 SNP309 is also associated with HCC. However, the role of SNP309 in hepatocarcinogenesis with respect to TP53 mutations is unknown. In this study, we investigated the distribution of the MDM2 SNP309 genotype and somatic TP53 (the p53 tumor suppressor gene) mutations in 99 human HCC samples from Africa, Europe, China and Japan. Samples exhibited striking geographical differences in their distribution of SNP309 genotypes. The frequency and spectrum of p53 mutations also varied geographically; TP53 mutations were frequent in Africa, where the SNP309 T/T genotype predominated but were rare in Europe and Japan, where the SNP309 G allele was present more frequently. TP53 mutations were detected in 18% (4/22) of SNP309 T/G and G/G and 82% (18/22) of SNP309 T/T genotype holders; this difference was statistically highly significant (P-value=0.0006). Our results indicated that the presence of the SNP309 G allele is inversely associated with the presence of somatic TP53 mutations because they only coincided in 4% of HCC cases. This finding suggests that the SNP309 G allele may functionally replace p53 mutations, and in addition to known etiological factors, may be partly responsible for differential HCC prevalence.

Analyses of Copy Number Variations in Myxopapillary Ependymomas of Cauda Equina.

AIM: To identify the copy number variations that are specific to myxopapillary ependymomas (MPEs) of the cauda equina. MATERIAL AND METHODS: The patient cohort included five patients who underwent resection of histologically confirmed MPEs. Tumor samples collected during surgery and stored in liquid nitrogen as well as corresponding blood samples collected were analyzed. Genomic DNA from the venous blood and tumor samples was obtained using standard techniques and hybridized to a Cytoscan 750K Array in accordance with the manufacturer’s introductions. RESULTS: As a novel finding, amplification on chromosome 14q32.33 was detected in all tumor and blood samples, except one tumor sample. All tumor tissues also showed amplification on chromosomes 5, 7, 9, and 16. CONCLUSION: Although further studies with larger cohorts are required to identify genes involved in MPE tumorigenesis and to validate our results, these findings provide a basis for advanced molecular biological and genetic studies of MPEs.

Toward In Vitro Epigenetic Drug Design for Thyroid Cancer: The Promise of PF-03814735, an Aurora Kinase Inhibitor.

Thyroid cancer (TC) is a very common malignancy worldwide. Chief among the innovative molecular drug targets for TC are epigenetic modifications. Increased telomerase activity in cancer cells makes telomerase a novel target for epigenetic anticancer drug innovation. Recently, telomerase reverse transcriptase (TERT) gene promoter (TERTp) mutations (C228T and C250T) were reported at high frequency in TC cell lines and tumor biopsies. In this study, three representative TC cell lines, mutant TERTp (TPC1), mutant BRAF/TERTp (KTC2), and wild-type TERTp (WRO), were screened with a drug library composed of 51 epigenetic drugs: 14 Aurora kinase inhibitors; 23 histone deacetylase inhibitors; 5 sirtuin modifiers; 3 hypoxia-inducible factor inhibitors; 2 DNA methyltransferase inhibitors; 2 histone methyltransferase inhibitors, a histone demethylase inhibitor, and a bromodomain inhibitor. Effects of the drugs on cell growth at 48 and 72 h were compared. PF-03814735, a small-molecule inhibitor of Aurora kinase A (IC50 = 0.8 nM) and B (IC50 = 5 nM), was the most potent on KTC2 cells, whereas CUDC-101, a multitarget inhibitor, was effective on both WRO and KTC2 cells. Notably, PF-03814735 was found to be the most effective epigenetic drug on cell lines harboring the C228T mutation. In conclusion, these new findings offer specific guidance on dose and time course selection to design novel therapeutic interventions against TC using PF-03814735, and specifically target cells carrying the TERTpC228T mutation. In a larger context of drug discovery science, these findings inform new strategies to forecast optimal treatment regimens for TC, particularly with Aurora kinase inhibitors and in ways guided by epigenetic drug design.

Role of FLT3 in the proliferation and aggressiveness of hepatocellular carcinoma.

BACKGROUND/AIM: Previously we showed that Fms-like tyrosine kinase (FLT3) changes its cellular localization upon partial hepatectomy, suggesting a role in liver regeneration. FLT3 was also shown to play an important function in cellular proliferation and activation of PI3K and Ras. Thus, we aimed to investigate the role of FLT3 in hepatocellular tumorigenesis utilizing in vitro and in vivo models. MATERIALS AND METHODS: We used Snu398 cells that express FLT3. We investigated these cells' in vitro proliferation and invasion abilities by treatment with the FLT3 inhibitor K-252a or by knocking-down with FLT3 shRNA,. Furthermore, the effect of blocking FLT3 activity and expression during in vivo tumorigenesis was assessed with xenograft models. RESULTS: After K-252a treatment or stable knock-down, these cells' proliferation and migration abilities were highly diminished in vitro. In addition, significant diminution in tumorigenicity of Snu398 cells was also obtained in vivo. When FLT3 knocked-down Snu398 cells were injected into nude mice, we did not detect αSMA expression in these tumors, suggesting a role for FLT3 in in vivo invasiveness. CONCLUSION: Our data provided evidence that FLT3 has a crucial role both in hepatocarcinogenesis and its invasiveness. Therefore, targeting FLT3 and/or its activity may be a promising tool for combating hepatocellular carcinomas.

Chromosome 22q12.1 microdeletions: confirmation of the MN1 gene as a candidate gene for cleft palate.

We report on seven novel patients with a submicroscopic 22q12 deletion. The common phenotype constitutes a contiguous gene deletion syndrome on chromosome 22q12.1q12.2, featuring NF2-related schwannoma of the vestibular nerve, corpus callosum agenesis and palatal defects. Combining our results with the literature, eight patients are recorded with palatal defects in association with haploinsufficiency of 22q12.1, including the MN1 gene. These observations, together with the mouse expression data and the finding of craniofacial malformations including cleft palate in a Mn1-knockout mouse model, suggest that this gene is a candidate gene for cleft palate in humans.

Association of Pre-miRNA-499 rs3746444 and Pre-miRNA-146a rs2910164 Polymorphisms and Susceptibility to Behcet's Disease.

MiRNAs and NFKB1 are well-known immune response and inflammation regulators. MiRNA gene polymorphisms may affect miRNA biogenesis and function and, may thus, lead to changes in the expression of hundreds of genes such as NFKB1. The aim of this study was to investigate the association of Behcet's disease (BD) with NFKB1 rs28362491, pre-miRNA-146a rs2910164, and pre-miRNA-499 rs3746444 polymorphisms, as well as the analysis of their single and combined effects on its susceptibility in a Turkish population. These polymorphisms were analyzed by using the polymerase chain reaction-restriction fragment length polymorphism method in 100 BD patients and 145 healthy control subjects. The results were analyzed statistically using Pearson chi-square (χ(2)) test and Fisher's exact test (two sided). According to genotype analysis, the frequencies of ins/ins genotype and ins allele of rs28362491 were considerably higher in BD patients. Also, miRNA-499 rs3746444 homozygous (TT) genotypes exibited a significantly higher risk in patients with BD (odds ratios [OR]=3.0, 95% confidence intervals [95% CI]=1.284-7.007, p=0.017). Moreover, the frequency of T allele of rs3746444 was a risk factor for BD (OR=1.562, 95% CI=1.087-2.24, p=0.015). In addition, significant differences were found between the groups concerning miRNA-146a rs2910164 polymorphism. Homozygous CC genotype and C allele of rs2910164 polymorphism were found to be protective factors against BD. The results of the combined genotype analysis showed no notable differences between the multiple comparisons of rs28362491-rs2910164 and of rs28362491-rs3746444 in patients and control groups. Our data demonstrate that homozygous CC genotype and C allele of rs2910164 polymorphism are protective factors against BD, but rs3746444 and rs28362491 polymorphisms in miRNA-499 and in NFKB1 promoter are involved in the genetic susceptibility of BD. In addition, TT and ins/ins genotypes may influence certain proinflammatory cytokines and, may thus, play a role in the pathogenesis of BD.

Translating biotechnology to knowledge-based innovation, peace, and development? Deploy a Science Peace Corps--an open letter to world leaders.

Scholarship knows no geographical boundaries. This science diplomacy and biotechnology journalism article introduces an original concept and policy petition to innovate the global translational science, a Science Peace Corps. Service at the new Corps could entail volunteer work for a minimum of 6 weeks, and up to a maximum of 2 years, for translational research in any region of the world to build capacity manifestly for development and peace, instead of the narrow bench-to-bedside model of life science translation. Topics for translational research are envisioned to include all fields of life sciences and medicine, as long as they are linked to potential or concrete endpoints in development, foreign policy, conflict management, post-crisis capacity building, and/or peace scholarship domains. As a new instrument in the global science and technology governance toolbox, a Science Peace Corps could work effectively, for example, towards elucidating the emerging concept of "one health"--encompassing human, environmental, plant, microbial, ecosystem, and planet health--thus serving as an innovative crosscutting pillar of 21(st) century integrative biology. An interdisciplinary program of this caliber for development would link 21(st) century life sciences to foreign policy and peace, in ways that can benefit many nations despite their ideological differences. We note that a Science Peace Corps is timely. The Intergovernmental Panel on Climate Change (IPCC) of the United Nations released the Fifth Assessment Report on March 31, 2014. Worrisomely, the report underscores that no person or nation will remain untouched by the climate change, highlighting the shared pressing life sciences challenges for global society. To this end, we recall that President John F. Kennedy advocated for volunteer work that has enduring, transgenerational, and global impacts. This culminated in establishment of the Peace Corps in 1961. Earlier, President Abraham Lincoln aptly observed, "nearly all men can stand adversity, but if you want to test a man's character, give him power." We therefore petition President Barack Obama, other world leaders, and international development agencies in positions of power around the globe, to consider deploying a Science Peace Corps to cultivate the essential (and presently missing) ties among life sciences, foreign policy, development, and peace agendas. A Science Peace Corps requires support by a credible and independent intergovernmental organization or development agency for funding, and arbitration in the course of volunteer work when the global versus local (glocal) value-based priorities and human rights intersect in synergy or conflict. In all, Science Peace Corps is an invitation to a new pathway for competence in 21(st) century science that is locally productive and globally competitive. It can open up scientific institutions to broader considerations and broader inputs, and thus cultivate vital translational science in a world sorely in need of solidarity and sustainable responses to the challenges of 21(st) century science and society.