Microwave-assisted dehydration, long-term storage at non-freezing temperatures, and rehydration of cat germinal vesicles.

Germinal vesicles (GVs) are alternative targets for female fertility preservation due to their availability and high resilience against non-physiological conditions. Preserved GVs can then be transferred to fresh cytoplasts to reconstitute viable oocytes. Here, we describe a GV preservation method that employs non-ionizing microwave radiations imparting energy to water molecules, which results in rapid and homogeneous drying of the sample. Trehalose is added as a xero-protectant before the radiations, enabling isothermal vitrification of the disaccharide sugar during drying. While the technique is still considered experimental, studies have shown that DNA and structural integrity can be effectively maintained in dried/rehydrated GVs. Importantly, the dry-preservation approach allows supra-zero temperature storage of the samples, offering a cost-effective and energy-saving alternative to traditional methods relying on ultra-low freezing temperatures. The protocol outlines a comprehensive procedure involving GV oocyte collection, trehalose loading, microwave drying, storage, and rehydration. The simplicity of the protocol facilitates ease of manipulation, making it an accessible method for researchers. While initially developed for domestic cats, the protocol can be adapted for other species with necessary modifications, considering potential species-specific responses to dehydration stress.

Development of triazole-based PKC-inhibitors to overcome resistance to EGFR inhibitors in EGFR-mutant lung cancers.

Protein kinase C delta (PKCδ) is prominently expressed in the nuclei of EGFR-mutant lung cancer cells, and its presence correlates with poor survival of the patients undergoing EGFR inhibitor treatment. The inhibition of PKCδ has emerged as a viable approach to overcoming resistance to EGFR inhibitors. However, clinical-grade PKCδ inhibitors are not available, highlighting the urgent needs for the development of effective drugs that target PKCδ. In this study, we designed and synthesized a series of inhibitors based on the chemical structure of a pan PKC inhibitor sotrastaurin. This was achieved by incorporating a triazole ring group into the original sotrastaurin configuration. Our findings revealed that the sotrastaurin derivative CMU-0101 exhibited an elevated affinity for binding to the ATP-binding site of PKCδ and effectively suppressed nuclear PKCδ in resistant cells in comparison to sotrastaurin. Furthermore, we demonstrated that CMU-0101 synergistically enhanced EGFR TKI gefitinib sensitivity in resistant cells. Altogether, our study provides a promising strategy for designing and synthesizing PKCδ inhibitors with improved efficacy, and suggests CMU-0101 as a potential lead compound to inhibit PKCδ and overcome TKI resistance in lung cancers.

Inhibition of Galectin-9 sensitizes tumors to anthracycline treatment via inducing antitumor immunity.

Anthracyclines are a class of conventionally and routinely used first-line chemotherapy drugs for cancer treatment. In addition to the direct cytotoxic effects, increasing evidence indicates that the efficacy of the drugs also depends on immunomodulatory effects with unknown mechanisms. Galectin-9 (Gal-9), a member of the ß-galactoside-binding protein family, has been demonstrated to induce T-cell death and promote immunosuppression in the tumor microenvironment. Here, we asked whether anthracycline-mediated immunomodulatory activity might be related to Gal-9. We found that combining doxorubicin with anti-Gal-9 therapy significantly inhibited tumor growth and prolonged overall survival in immune-competent syngeneic mouse models. Moreover, Gal-9 expression was increased in response to doxorubicin in various human and murine cancer cell lines. Mechanistically, doxorubicin induced tumoral Gal-9 by activating the STING/interferon ß pathway. Clinically, Gal-9 and p-STING levels were elevated in the tumor tissues of breast cancer patients treated with anthracyclines. Our study demonstrates Gal-9 upregulation in response to anthracyclines as a novel mechanism mediating immune escape and suggests targeting Gal-9 in combination with anthracyclines as a promising therapeutic strategy for cancer treatment.

The Effect of Choline Salt Addition to Trehalose Solution for Long-Term Storage of Dried and Viable Nuclei from Fully Grown Oocytes.

Although drying techniques are exciting alternatives to cryopreservation, it remains challenging to maintain tightly controlled temperatures and humidity levels during storage of dried products. The objective of this study was to determine if the addition of choline acetate to trehalose solution could enable a wider range of storage conditions for preservation of nuclei from fully grown oocytes, by allowing temporary humidity excursions (>44% relative humidity) that may lead to crystallization of trehalose and loss of DNA integrity. Using domestic cat germinal vesicle oocytes as a model, we characterized the recovery as well as the integrity of samples after microwave-assisted dehydration. Exposure to choline acetate alone did not impair the germinal vesicle's DNA integrity and only had a negative impact on the chromatin configuration. Choline acetate addition enabled us to reach lower moisture contents after 25 min of microwave-assisted drying. Sample recovery after rehydration was also better in the presence of choline acetate. The integrity of the germinal vesicle's DNA was not affected, while the chromatin configuration was impaired by the presence of choline acetate during dehydration. Importantly, choline acetate addition helped to maintain an amorphous state (absence of detrimental crystallization) during excursion from ideal humidity conditions.

The Effects of a Curcumin Derivative and Osimertinib on Fatty Acyl Metabolism and Mitochondrial Functions in HCC827 Cells and Tumors.

Drug combination therapy is a key approach in cancer treatments, aiming to improve therapeutic efficacy and overcome drug resistance. Evaluation of intracellular response in cancer cells to drug treatment may disclose the underlying mechanism of drug resistance. In this study, we aimed to investigate the effect of osimertinib, a tyrosine kinase inhibitor (TKI), and a curcumin derivative, 35d, on HCC827 cells and tumors by analyzing alterations in metabolome and related regulations. HCC827 tumor-bearing SCID mice and cultured HCC827 cells were separately examined. The treatment comprised four conditions: vehicle-only, 35d-only, osimertinib-only, and a combination of 35d and osimertinib. The treated tumors/cells were subsequently subjected to metabolomics profiling, fatty acyl analysis, mitochondrial potential measurement, and cell viability assay. Osimertinib induced changes in the ratio of short-chain (SC) to long-chain (LC) fatty acyls, particularly acylcarnitines (ACs), in both tumors and cells. Furthermore, 35d enhanced this effect by further lowering the SC/LC ratio of most ACs. Osimertinib and 35d also exerted detrimental effects on mitochondria through distinct mechanisms. Osimertinib upregulated the expression of carnitine palmitoyltransferase I (CPTI), while 35d induced the expression of heat shock protein 60 (HSP60). The alterations in ACs and CPTI were correlated with mitochondrial dysfunction and inhibited cell growth. Our results suggest that osimertinib and 35d disrupted the fatty acyl metabolism and induced mitochondrial stress in cancer cells. This study provides insights into the potential application of fatty acyl metabolism inhibitors, such as osimertinib or other TKIs, and mitochondrial stress inducers, such as curcumin derivatives, as combination therapy for cancer.

Trehalose delivered by cold-responsive nanoparticles improves tolerance of cumulus-oocyte complexes to microwave drying.

PURPOSE: Trehalose is a non-permeable protectant that is the key to preserve live cells in a dry state for potential storage at ambient temperatures. After intracellular trehalose delivery via cold-responsive nanoparticles (CRNPs), the objective was to characterize the tolerance of cat cumulus-oocyte complexes (COCs) to different levels of microwave-assisted dehydration. METHODS: Trehalose was first encapsulated in CRNPs. After exposure to trehalose-laden CRNPs, different water amounts were removed from cat COCs by microwave drying. After each dehydration level, meiotic and developmental competences were evaluated via in vitro maturation, fertilization, and embryo culture. In addition, expressions of critical genes were assessed by quantitative RT-PCR. RESULTS: CRNPs effectively transported trehalose into COCs within 4 h of co-incubation at 38.5 °C followed by a cold-triggered release at 4 °C for 15 min. Intracellular presence of trehalose enabled the maintenance of developmental competence (formation of blastocysts) as well as normal gene expression levels of HSP70 and DNMT1 at dehydration levels reaching up to 63% of water loss. CONCLUSION: Intracellular trehalose delivery through CRNPs improves dehydration tolerance of COCs, which opens new options for oocyte storage and fertility preservation at ambient temperatures.

Diarylheptanoid 35d overcomes EGFR TKI resistance by inducing hsp70-mediated lysosomal degradation of EGFR in EGFR-mutant lung adenocarcinoma.

Epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma (LUAD) patients often respond to EGFR tyrosine kinase inhibitors (TKIs) initially but eventually develop resistance to TKIs. The switch of EGFR downstream signaling from TKI-sensitive to TKI-insensitive is a critical mechanism-driving resistance to TKIs. Identification of potential therapies to target EGFR effectively is a potential strategy to treat TKI-resistant LUADs. In this study, we developed a small molecule diarylheptanoid 35d, a curcumin derivative, that effectively suppressed EGFR protein expression, killed multiple TKI-resistant LUAD cells in vitro, and suppressed tumor growth of EGFR-mutant LUAD xenografts with variant TKI-resistant mechanisms including EGFR C797S mutations in vivo. Mechanically, 35d triggers heat shock protein 70-mediated lysosomal pathway through transcriptional activation of several components in the pathway, such as HSPA1B, to induce EGFR protein degradation. Interestingly, higher HSPA1B expression in LUAD tumors associated with longer survival of EGFR-mutant, TKI-treated patients, suggesting the role of HSPA1B on retarding TKI resistance and providing a rationale for combining 35d with EGFR TKIs. Our data showed that combination of 35d significantly inhibits tumor reprogression on osimertinib and prolongs mice survival. Overall, our results suggest 35d as a promising lead compound to suppress EGFR expression and provide important insights into the development of combination therapies for TKI-resistant LUADs, which could have translational potential for the treatment of this deadly disease.

Highly Mimetic Ex Vivo Lung-Cancer Spheroid-Based Physiological Model for Clinical Precision Therapeutics.

Lung cancer remains a major health problem despite the considerable research into prevention and treatment methods. Through a deeper understanding of tumors, patient-specific ex vivo spheroid models with high specificity can be used to accurately investigate the cause, metastasis, and treatment strategies for lung cancer. Biofabricate lung tumors are presented, consisting of patient-derived tumor spheroids, endothelial cells, and lung decellularized extracellular matrix, which maintain a radial oxygen gradient, as well as biophysicochemical behaviors of the native tumors for precision medicine. It is also demonstrated that the developed lung-cancer spheroid model reproduces patient responses to chemotherapeutics and targeted therapy in a co-clinical trial, with 85% accuracy, 86.7% sensitivity, and 80% specificity. RNA sequencing analysis validates that the gene expression in the spheroids replicates that in the patient's primary tumor. This model can be used as an ex vivo predictive model for personalized cancer therapy and to improve the quality of clinical care.

Current knowledge in the biology of gametes and embryos from Carnivora.

In addition to companion animals and laboratory species, about 270 carnivore species play fundamental ecological roles in different ecosystems. However, almost 40% of carnivore species are now threatened or endangered in the wild because of human activities. While protection of natural habitats is critical, it is equally important to better understand carnivore reproduction, including a solid knowledge in sperm, oocyte, and embryo biology, to maintain sustainable populations in the wild and in conservation breeding centers. Characterizing gamete and embryo biology is also needed to develop cryopreservation and assisted reproductive technologies to enhance conservation efforts. The objective of this review is to provide the most recent knowledge in the biology of sperm cells, oocytes, and early embryos across all carnivore families. Overall, most data originate from populations maintained in breeding centers or zoos. Characterizations of sperm biology and cryopreservation are far more advanced than for oocytes and embryos. Currently, sperm biology is mainly studied in Canids, Felids, Ursids, and Mustelids, with more emphasis on structural than functional properties. Importantly, fundamental studies of gamete and embryo biology in domestic dogs, cats, and ferrets have paved the way for more precise characterizations in wild counterparts as well as the development of cryopreservation and assisted reproductive technologies. A striking feature of spermatozoa across a wide range of Canids and Felids is the presence of teratospermia (>60% of abnormal sperm cells), which is related to the loss of genetic diversity in some populations. Although sperm structures differ across carnivore families, sperm biology remains difficult to compare because of the small amount of data in many species. Regarding oocyte biology and embryology, data are much scarcer than in sperm cells, with too few studies going beyond structural descriptions. More carnivore species and more individuals (especially from wild populations in addition to captive ones) must be studied to improve our understanding about comparative germplasm biology and develop adequate conservation breeding strategies including the use of cryobanking and assisted reproductive technologies.

Damages and stress responses in sperm cells and other germplasms during dehydration and storage at nonfreezing temperatures for fertility preservation.

Long-term preservation of sperm, oocytes, and gonadal tissues at ambient temperatures has the potential to lower the costs and simplify biobanking in human reproductive medicine, as well as for the management of animal populations. Over the past decades, different dehydration protocols and long-term storage solutions at nonfreezing temperatures have been explored, mainly for mammalian sperm cells. Oocytes and gonadal tissues are more challenging to dehydrate so little to no progress have been made. Currently, the detrimental effects of the drying process itself are better characterized than the impact of long-term storage at nonfreezing temperatures. While structural and functional properties of germ cells can be preserved after dehydration, a long list of damages and stresses in nuclei, organelles, and cytoplasmic membranes have been reported and sometimes mitigated. Characterizing those damages and better understanding the response of germ cells and tissues to the stress of dehydration is fundamental. It will contribute to the development of optimal protocols while proving the safety of alternative storage options for fertility preservation. The objective of this review is to (1) document the types of damages and stress responses, as well as their mitigation in cells dried with different techniques, and (2) propose new research directions.

Long-term preservation of germ cells and gonadal tissues at ambient temperatures.

Objective: To present an overview of different approaches and recent advances for long-term preservation of germ cells and gonadal tissues at ambient temperatures. Methods: Review of the existing literature. Results: Preserving viable spermatozoa, eggs, embryos, and gonadal tissues for the long term is critical in human fertility treatment and for the management of animal populations (livestock, biomedical models, and wild species). The need and number of banked germplasms are growing very fast in all disciplines, but current storage options at freezing temperatures are often constraining and not always sustainable. Recent research indicates that structures and functions of gametes or gonadal tissues can be preserved for the long term using different strategies based on dehydration and storage at supra-zero temperatures. However, more studies are needed in rehydration and reanimation of germplasms (including proper molecular and cellular evaluations). Conclusions: While a lot of research is still warranted to optimize drying and rehydration conditions for each sample type and each species, alternative preservation methods will change the paradigm in fertility preservation and biobanking. It will transform the way we maintain and manage precious biomaterials for the long term. Lay summary: Living sperm cells, eggs, embryos, and reproductive tissues can be preserved at freezing temperatures for human fertility treatments and used to manage breeding in livestock, laboratory animals, and wild species through assisted reproduction. These cells can be stored in cell banks and demand for them is growing fast. However, current long-term storage options at freezing temperatures are expensive. Instead of using low temperatures, recent research indicates that these cells can be dried and stored above freezing temperatures for an extended amount of time. While a lot of research is still needed to optimize how different samples are dried and rehydrated, alternative methods of preserving cells will make fertility preservation and cell banking easier. It will also transform the way we keep and manage samples for the long term.

Desiccated cat spermatozoa retain DNA integrity and developmental potential after prolonged storage and shipping at non-cryogenic temperatures.

PURPOSE: To evaluate the DNA integrity and developmental potential of microwave-dehydrated cat spermatozoa after storage at - 20 °C for different time periods and/or overnight shipping on dry ice. METHODS: Epididymal spermatozoa from domestic cats were microwave-dehydrated on coverslips after trehalose exposure. Dried samples were either assessed immediately, stored for various duration at - 20 °C, or shipped internationally on dry ice before continued storage. Dry-stored spermatozoa were rehydrated before assessing DNA integrity (TUNEL assays) or developmental potential (injection into in vitro matured oocytes followed by in vitro embryo culture for up to 7 days). RESULTS: Percentages of dried-rehydrated spermatozoa with intact DNA was not significantly affected (P > 0.05) by desiccation and short-term storage (range, 78.9 to 80.0%) but decreased (P < 0.05) with storage over 5 months (range, 71.0 to 75.2%) compared to fresh controls (92.6 ± 2.2%). After oocyte injection with fresh or dried-rehydrated spermatozoa (regardless of storage time), percentages of activation, pronuclear formation, and embryo development were similar (P > 0.05). Importantly, spermatozoa shipped internationally also retained the ability to support embryo development up to the morula stage. CONCLUSION: Results demonstrated the possibility to sustain DNA integrity and developmental potential of spermatozoa by dry-preservation, even after long-term storage and long-distance shipment at non-cryogenic temperatures. While further studies are warranted, present results demonstrate that dry preservation can be a reliable approach for simple and cost-effective sperm biobanking or shipment.

Synthesis and Characterization of the Ethylene-Carbonate-Linked L-Valine Derivatives of 4,4-Dimethylcurcumin with Potential Anticancer Activities.

Natural phenolic products from herbal medicines and dietary plants constitute the main source of lead compounds for the development of the new drug. 4,4-Dimethylcurcumin (DMCU) is a synthetic curcumin derivative and exhibits anticancer activities against breast, colon, lung, and liver cancers. However, further development of DMCU is limited by unfavorable compound properties such as very low aqueous solubility and moderate stability. To increase its solubility, we installed either or both of the ethylene-carbonate-linked L-valine side chains to DMCU phenolic groups and produced targeted 1-trifluoroacetic acid (1-TFA) and 2-trifluoroacetic acid (2-TFA) derivatives. The terminus L-valine of ethylene-carbonate-linked side chain is known to be a L-type amino acid transporter 1 (LAT1) recognition element and therefore, these two derivatives were expected to readily enter into LAT1-expressing cancer cells. In practice, 1-TFA or 2-TFA were synthesized from DMCU in four steps with 34-48% overall yield. Based on the corresponding LC-MS analysis, water solubility of DMCU, 1-TFA, and 2-TFA at room temperature (25 ± 1 °C) were 0.018, 249.7, and 375.8 mg/mL, respectively, indicating >10,000-fold higher solubility of 1-TFA and 2-TFA than DMCU. Importantly, anti-proliferative assay demonstrated that 2-TFA is a potent anti-cancer agent against LAT1-expressing lung cancer cells NCI-H460, NCI-H358, and A549 cells due to its high intracellular uptake compared to DMCU and 1-TFA. In this study, we logically designed and synthesized the targeted compounds, established the LC-MS analytical methods for evaluations of drug solubility and intracellular uptake levels, and showed improved solubility and anti-cancer activities of 2-TFA. Our results provide a strategical direction for the future development of curcuminoid-like phenolic compounds.

Oocyte Meiotic Competence in the Domestic Cat Model: Novel Roles for Nuclear Proteins BRD2 and NPM1.

To participate in fertilization and embryo development, oocytes stored within the mammalian female ovary must resume meiosis as they are arrested in meiotic prophase I. This ability to resume meiosis, known as meiotic competence, requires the tight regulation of cellular metabolism and chromatin configuration. Previously, we identified nuclear proteins associated with the transition from the pre-antral to the antral follicular stage, the time at which oocytes gain meiotic competence. In this study, the objective was to specifically investigate three candidate nuclear factors: bromodomain containing protein 2 (BRD2), nucleophosmin 1 (NPM1), and asparaginase-like 1 (ASRGL1). Although these three factors have been implicated with folliculogenesis or reproductive pathologies, their requirement during oocyte maturation is unproven in any system. Experiments were conducted using different stages of oocytes isolated from adult cat ovaries. The presence of candidate factors in developing oocytes was confirmed by immunostaining. While BRD2 and ASRGL1 protein increased between pre-antral and the antral stages, changes in NPM1 protein levels between stages were not observed. Using protein inhibition experiments, we found that most BRD2 or NPM1-inhibited oocytes were incapable of participating in fertilization or embryo development. Further exploration revealed that inhibition of BRD2 and NPM-1 in cumulus-oocyte-complexes prevented oocytes from maturing to the metaphase II stage. Rather, they remained at the germinal vesicle stage or arrested shortly after meiotic resumption. We therefore have identified novel factors playing critical roles in domestic cat oocyte meiotic competence. The identification of these factors will contribute to improvement of domestic cat assisted reproduction and could serve as biomarkers of meiotically competent oocytes in other species.

Preserving the Female Genome in Trehalose Glass at Supra-Zero Temperatures: The Relationship Between Moisture Content and DNA Damage in Feline Germinal Vesicles.

INTRODUCTION: Maintaining a stable dry state is critical for long-term preservation of live biomaterials at suprazero temperatures. The objective of the study was to characterize the effect of moisture content on DNA integrity within the germinal vesicle (GV) of feline oocytes following dehydration and storage at 22-24 °C. METHODS: Using microwave-assisted drying, conditions that led to a predictable and stable moisture content in trehalose solutions were determined. To explore moisture content stability during storage, trehalose samples were dried for 15 min and stored in glass vials at 11 or 43% RH for 8 weeks. To examine whether this condition allowed proper storage of GVs, permeabilized cat oocytes were incubated in trehalose for 10 min and dried for 15 or 30 min. Oocytes then were rehydrated to assess DNA integrity either directly after drying or after 8 weeks of storage in an 11% RH environment. Raman spectroscopy was used to identify the states of dried samples during storage. RESULTS: Moisture content was stable during the storage period. There was no significant difference in DNA integrity between fresh and dried samples without storage. After 8 weeks of storage, DNA integrity was maintained in GVs dried for 30 min. Samples dried for 15 min and stored were compromised, suggesting crystallization of the preservation matrix during storage. Biostabilization was optimal when samples were directly processed to moisture contents consistent with storage in the glassy state. CONCLUSION: Microwave-assisted drying processing and storage conditions were optimized to ensure stable long-term storage of structural and functional properties of genetic resources.

Erratum: The stabilization of PD-L1 by the endoplasmic reticulum stress protein GRP78 in triple-negative breast cancer.

[This corrects the article on p. 2621 in vol. 10, PMID: 32905506.].

Targeting positive feedback between BASP1 and EGFR as a therapeutic strategy for lung cancer progression.

Rationale: Brain metastasis in patients with lung cancer is life-threatening. However, the molecular mechanism for this catastrophic disease remains elusive, and few druggable targets are available. Therefore, this study aimed to identify and characterize proteins that could be used as therapeutic targets. Methods: Proteomic analyses were conducted to identify differentially expressed membrane proteins between brain metastatic lung cancer cells and primary lung cancer cells. A neuronal growth-associated protein, brain acid soluble protein 1 (BASP1), was chosen for further investigation. The clinical relevance of BASP1 in lung adenocarcinoma was first assessed. Tyrosine kinase activity assays and in vitro and in vivo functional assays were conducted to explore the oncogenic mechanisms of BASP1. Results: The protein levels of BASP1 were positively associated with tumor progression and poor prognosis in patients with lung adenocarcinoma. Membrane-bound BASP1 increased EGFR signaling and stabilized EGFR proteins by facilitating their escape from the ubiquitin-proteasome pathway. Reciprocally, activation of EGFR recruited more BASP1 to the plasma membrane, generating a positive feedback loop between BASP1 and EGFR. Moreover, the synergistic therapeutic effects of EGFR tyrosine kinase inhibitor and arsenic trioxide led to a reduction in the level of BASP1 protein observed in lung cancer cells with acquired resistance to EGFR inhibitors. Conclusions: The reciprocal interaction between BASP1 and EGFR facilitates EGFR signaling in brain metastatic lung cancer. Targeting the newly identified BASP1-EGFR interaction could open new venues for lung cancer treatment.

The stabilization of PD-L1 by the endoplasmic reticulum stress protein GRP78 in triple-negative breast cancer.

The immune checkpoint blockade therapy has emerged as encouraging treatment strategies in various cancer types. Anti-PD-L1 (programmed death-ligand 1) antibodies have been approved for triple-negative breast cancer, however the response rate yet to be optimized. It would be imperative to further understand and investigate the molecular mechanisms of PD-L1 regulation. Here, we identified glucose regulatory protein 78 (GRP78), a major endoplasmic reticulum (ER) stress responding protein, as a novel binding partner of PD-L1. GRP78 interacts with PD-L1 at the ER region and increases PD-L1 levels via regulating its stability. ER stress, triggered by different stimuli such as conventional chemotherapy, leads to the induction of PD-L1 in a GRP78-dependent manner. We showed that GRP78 modulates the response to chemotherapy, and dual-high levels of GRP78 and PD-L1 correlates with poor relapse-free survival in triple-negative breast cancer. Altogether, our study provides novel molecular insights into the regulatory mechanism of PD-L1 by revealing its interaction with GRP78, and offers a rationale to target GRP78 as a potential therapeutic strategy to enhance anti-tumor immunity.

Influence of Microwave-Assisted Drying on Structural Integrity and Viability of Testicular Tissues from Adult and Prepubertal Domestic Cats.

Anhydrous preservation is a promising approach for storage of living biomaterials at nonfreezing temperatures. Using the domestic cat model, the objectives of this study were to characterize changes in histology, DNA integrity, and viability of testicular tissues from adult versus prepubertal individuals during microwave-assisted drying. Testes from each age group were cut into small pieces before reversible membrane permeabilization, exposure to trehalose, and microwave-assisted drying during different time periods. In Experiment 1, water content was monitored for up to 40 minutes of drying. Tissues from adult or prepubertal cats experienced similar decreases of water content during the first 10 minutes. Desiccation progressed slowly between 10 and 20 minutes and then remained stable. In Experiment 2, structural properties were explored at 5, 10, and 20 minutes of desiccation. Percentages of normal seminiferous tubules were lower after 20 minutes drying in adult (43%) than in prepubertal tissues (61%). At the same time point, the proportion of cell degeneration was higher in adult (53%) than prepubertal tissues (28%). Percentages of intact DNA in tissues remained above 85% regardless of the microwave time in both age groups. Lastly, adult and prepubertal tissues only lost 33% of viability in both age groups. Collective results demonstrated for the first time that normal morphology, incidence of degeneration, DNA integrity, and viability of testicular tissues remained at acceptable levels during microwave-assisted drying for 20 minutes. Overall, prepubertal testicular tissues appeared to be more resilient to microwave-assisted desiccations than adult tissues. Importantly, water loss in the presence of trehalose after 20 minutes of desiccation already is compatible with long-term storage of testicular tissues at temperatures above -20°C, which is one step closer to future storage at supra-zero temperatures.

Inhibition of c-MET upregulates PD-L1 expression in lung adenocarcinoma.

Non-small cell lung cancer (NSCLC) patients with c-MET dysregulation may benefit from c-MET inhibitors therapy as inhibition of c-MET activity has emerged as a therapeutic approach against this disease. Although several c-MET inhibitors have been evaluated in multiple clinical trials in lung cancer, their benefits so far have been modest. Thus, furthering our understanding of the mechanisms contributing to the lack of success of c-MET inhibitors in clinical trials is essential toward the development of rational and effective combination strategies. Here we show that exposure of NCSLC cell lines to c-MET inhibitor tivantinib increases their expression of PD-L1, which in turn causes cells to become more resistant to T-cell killing. Mechanistically, inhibition of c-MET suppresses p-GSK3ß, leading to the stabilization of PD-L1 similar to that observed in liver cancer cells. Collectively, our findings suggest a potential crosstalk between c-MET inhibition and immune escape and provide a rationale for the combination therapy of c-MET inhibitors and immune checkpoint blockade in NSCLC.