Species identification in cell culture: a two-pronged molecular approach

Establishment and Characterization of a New Cell Line from Enzootic Nasal Adenocarcinoma in Goats: ENA-1

Enzootic nasal adenocarcinoma (ENA) is a contagious tumor disease of goats and sheep, which is caused by enzootic nasal tumor virus (ENTV). To better understand the pathogenesis of ENA, this study aimed to establish a goat ENA cell line (ENA-1). The cells have been characterized with regard to morphology, growth rate, ultrastructural features, chromosome number, expression of CK7 and CK18, tumorigenicity, species, and mycoplasma contamination. ENA-1 had an epithelioid cell morphology with an unstable chromosome number under a light microscope. Under an electron microscope, the cell nuclear heterogeneity was not obvious, and there were more intermediate filaments and a small number of immature retrovirus-like particles in the cytoplasm. ENA-1 had strong proliferative potential, and the cell multiplication time was about 36 h, which could make BALB/c nude mice develop tumors. CK7 and CK18 were expressed in the cytoplasm of primary goat tumors, in transplanted tumors from nude mice, and un ENA-1 cells with the same intensity. PCR revealed that ENA-1 continuously carried ENTV-2 up to the 17th generation with no germline contamination or mycoplasma contamination. In conclusion, using a serum-containing culture system, ENA-1 cells were successfully isolated, cultured, and purified from goat tumor tissues. The isolated ENA-1 cells retained robust proliferation potential and maintained their phenotype, indicating the potential application of the ENA-1 cell line as an in vitro model of ENA.

Molecular identification of Borrelia and SFG Rickettsia spp. in hard ticks parasitizing domestic and wild animals in southeastern Spain

Lyme disease and the spotted fever group rickettsiosis, involve bacteria belonging to the genus Borrelia and Rickettsia, respectively. These infections are the most important tick-borne zoonotic diseases involving ticks as vectors. Descriptive and epidemiological studies are essential to determine the animal hosts involved in the maintenance of these diseases. In the present study, 94 tick pool samples from 15 different host species located in the Region of Murcia (southeastern, Spain) were analysed. Ticks were morphologically identified as: Dermacentor marginatus, Hyalomma lusitanicum, Ixodes Ricinus, and Rhipicephalus sanguineus. Our results showed that 5.3% of the tick pool samples carried Borrelia spp. DNA, and 20.2% carried SFG Rickettsia DNA. In every hard tick pool Spot Fever Group (SFG) Rickettsia spp. DNA were detected, except for H. lusitanicum. Likewise, D. marginatum was the only species in which Borrelia spp. DNA was not detected. Barbary sheep and wild boar were the host species in which tick pools showed DNA presence of both pathogens. This study increases the knowledge about the presence of Borrelia spp. DNA and SFG Rickettsia spp. DNA in different hard tick species from this geographical area.

Establishment of a cobia (Rachycentron canadum) gill cell line: A valuable tool for immune response studies

Cobia (Rachycentron canadum), a commercially important marine fish, has been used to develop a novel gill cell line, designated CG, for the first time. The CG cell line was cultured in Leibovitz's-15 medium with 5% fetal bovine serum (FBS) and successfully sub-cultured more than 110 passages. It underwent verification through sequencing of the mitochondrial cytochrome C oxidase subunit I (COI) gene. Optimal growth rate was achieved when the CG cell line was cultured in a medium supplemented with 5% FBS, 1% Penicillin-Streptomycin (P/S), and 5 parts per thousand (ppt) of coral sea salt water, maintained at a temperature of 27 °C. The addition of 5 ppt of salt in the growth medium suggests that this cell line could be a viable in vitro tool for marine ecosystem toxicological studies or for culturing marine parasitic microorganisms. The CG cell line was also successfully transfected using the pTurbo-GFP plasmids, showing an 18% efficiency, with observable GFP expression. Furthermore, the cell line has been effectively cryopreserved. Gene expression analysis indicated that the CG cell line exhibits responsive regulation of immune gene expression when exposured to various stimulants, highlighting its potential as an in vitro platform for immune response studies. This makes it suitable for exploring dynamic immune signaling pathways and host-pathogen interactions, thereby offering valuable insights for therapeutic development.

Development and characterization of a new muscle cell culture system from Clarias magur (Hamilton, 1822)

The cell line has been used as a novel in vitro tool for executing several studies in life sciences. The current study aimed to develop and characterize a muscle cell culture system derived from Clarias magur. The primary muscle cell cultures derived from the caudal peduncle muscle have been successfully sub cultured up to 13 passages to establish a new muscle cell culture system known as CMM. At a temperature of 28 °C, L-15 medium supplemented with 20% FBS produced the maximum growth of muscle cells. However, muscle cells were optimized to grow at 10% FBS. To enhance the proliferation capacity of the CMM cells, a growth-promoting factor bFGF (10 ng/ml) was added, thereby reducing the time interval of passages for the subsequent cultures. DNA barcoding of the CMM cell culture system authenticated the species of origin. The cell culture system was successfully cryopreserved by a slow freezing procedure at - 80 °C with a revival efficiency of 60%.

Establishment and characterization of a novel kidney cell line derived from the common bottlenose dolphin

Common bottlenose dolphin (Tursiops truncatus) is a well-known cetacean species that inhabits temperate and tropical seas worldwide. Limited supply and poor quality of samples hinder the investigation of the effects of various pathogens and environmental pollutants on this cetacean species. Cultured cells are useful for experimental studies; however, no cell lines derived from cetaceans are generally available. Therefore, in this study, we established a novel kidney cell line, TK-ST, derived from T. truncatus. Primary cells exhibited the morphological characteristics of epithelial and fibroblast cells, but their immortalization and passaging resulted in a predominantly epithelial cell morphology. TK-ST was immortalized using the large T SV40 antigen and human telomerase reverse transcriptase and exhibited long-term stable cell growth. TK-ST cells are generally cultured in Dulbecco's modified Eagle's medium with 10% fetal bovine serum at 37°C and 5% CO2 but can also be cultured in 5-20% fetal bovine serum and several other classical media commonly used for common animal cell culture. TK-ST cells were found to be susceptible to several viruses, including the dolphin morbillivirus (most important virus in cetaceans), and exhibited cytopathic effects, facilitating the replication of the dolphin morbillivirus. Furthermore, mRNA expression levels of cytokine genes were increased in TK-ST cells after stimulation with lipopolysaccharides and poly(I:C). Therefore, the novel TK-ST cell line derived in this study can potentially be used for further in vitro studies on cetaceans.

Integrated analysis of canine soft tissue sarcomas identifies recurrent mutations in TP53, KMT genes and PDGFB fusions

Soft tissue sarcomas (STS) are a heterogenous group of mesenchymal tumors representing over 50 distinct types with overlapping histological features and non-specific anatomical locations. Currently, localized sarcomas are treated with surgery + / -  radiation in both humans and dogs with few molecularly targeted therapeutic options. However, to improve precision-based cancer therapy through trials in pet dogs with naturally occurring STS tumors, knowledge of genomic profiling and molecular drivers in both species is essential. To this purpose, we sought to characterize the transcriptomic and genomic mutation profiles of canine STS subtypes (fibrosarcoma, undifferentiated pleomorphic sarcoma, and peripheral nerve sheath tumors), by leveraging RNAseq, whole exome sequencing, immunohistochemistry, and drug assays. The most common driver mutations were in cell cycle/DNA repair (31%, TP53-21%) and chromatin organization/binding (41%, KMT2D-21%) genes. Similar to a subset of human sarcomas, we identified fusion transcripts of platelet derived growth factor B and collagen genes that predict sensitivity to PDGFR inhibitors. Transcriptomic profiling grouped these canine STS tumors into 4 clusters, one PNST group (H1), and 3 FSA groups selectively enriched for extracellular matrix interactions and PDFGB fusions (H2), homeobox transcription factors (H3), and elevated T-cell infiltration (H4). This multi-omics approach provides insights into canine STS sub-types at a molecular level for comparison to their human counterparts, to improve diagnosis, and may provide additional targets for chemo- and immuno-therapy.

Establishment of a BRAF V595E-mutant canine prostate cancer cell line and the antitumor effects of MEK inhibitors against canine prostate cancer

Canine prostate cancer (cPCa) is a malignant neoplasm with no effective therapy. The BRAF V595E mutation, corresponding to the human BRAF V600E mutation, is found frequently in cPCa. Activating BRAF mutations are recognized as oncogenic drivers, and blockade of MAPK/ERK phosphorylation may be an effective therapeutic target against BRAF-mutated tumours. The aim of this study was to establish a novel cPCa cell line and to clarify the antitumor effects of MEK inhibitors on cPCa in vitro and in vivo. We established the novel CHP-2 cPCa cell line that was derived from the prostatic tissue of a cPCa patient. Sequencing of the canine BRAF gene in two cPCa cell lines revealed the presence of the BRAF V595E mutation. MEK inhibitors (trametinib, cobimetinib and mirdametinib) strongly suppressed cell proliferation in vitro, and trametinib showed the highest efficacy against cPCa cells with minimal cytotoxicity to non-cancer COPK cells. Furthermore, we orally administered 0.3 or 1.0 mg/kg trametinib to CHP-2 xenografted mice and examined its antitumor effects in vivo. Trametinib reduced tumour volume, decreased phosphorylated ERK levels, and lowered Ki-67 expression in xenografts in a dose-dependent manner. Although no clear adverse events were observed with administration, trametinib-treated xenografts showed osteogenesis that was independent of dosage. Our results indicate that trametinib induces cell cycle arrest by inhibiting ERK activation, resulting in cPCa tumour regression in a dose-dependent manner. MEK inhibitors, in addition to BRAF inhibitors, may be a targeted agent option for cPCa with the BRAF V595E mutation.

Establishment and characterization of a new fibroblast-like cell line from the skin of a vertebrate model, zebrafish (Danio rerio)

BACKGROUND

The available fully sequenced genome and genetic similarities compared to humans make zebrafish a prominent in vitro vertebrate model for drug discovery & screening, toxicology, and radiation biology. Zebrafish also possess well developed immune systems which is ideal for studying infectious diseases. Fish skin confers immunity by serving as a physical barrier against the invading pathogens in the aquatic habitat. Therefore in vitro models from the skin tissue of zebrafish help to study the physiology, functional genes in vitro, wound healing, and pathogenicity of microbes. Hence the study aimed to develop and characterize a skin cell line from the wild-type zebrafish Danio rerio.

METHODS AND RESULTS

A novel cell line designated as DRS (D. rerio skin) was established and characterized from the skin tissue of wild-type zebrafish, D. rerio, by the explant technique. The cells thrived well in the Leibovitz's -15 medium supplemented with 15% FBS and routinely passaged at regular intervals. The DRS cells mainly feature fibroblast-like morphology. The culture conditions of the cells were determined by incubating the cells at varying concentrations of FBS and temperature; the optimum was 15% FBS and 28 °C, respectively. Cells were cryopreserved and revived with 70-75% viability at different passage levels. Two extracellular products from bacterial species Aeromonas hydrophila and Edwardsiella tarda were tested and found toxic to the DRS cells. Mitochondrial genes, namely COI and 16S rRNA PCR amplification and partial sequencing authenticated the species of origin of cells. The modal diploid (2n) chromosome number of the cells was 50. The cell line DRS was found to be free from mycoplasma. The cells were transfected with pMaxGFP plasmid and tested positive for green fluorescence at 24-48 h post-transfection.

CONCLUSION

The findings from this study thus confirm the usefulness of the developed cell line in bacterial susceptibility and transgene expression studies.

Sık Kullanılan Bazı Hücre Hatları için Kalite Kontrol: Mikoplazma Kontaminasyon Tespiti, Sitokrom B ve Sitokrom Oksidaz Alt Birim I Genlerinin DNA Dizi Analizlerinin Gerçekleştirilmesi

Amaç: Laboratuvarlarda sık kullanılan serviks epitelyal karsinom (HeLa), insan periferal kan promiyelösitik lösemi (HL-60), fare C3/bağ dokusu (L929), Madin Darby köpek böbrek (MDCK), fare nöroblastom (Neuro-2a) gibi bazı hücre hatlarının mikoplazma kontaminasyon kontrollerinin yapılması, kimlik doğrulamalarının gerçekleştirilmesi ve klonalitelerinin belirlenmesidir.Yöntem: Bu çalışmada üç farklı türe ait beş hücre hattı kullanılmıştır. Çalışılan tüm hatların Bisbenzimid (Hoechst 33258) ile deoksiribonükleik asit (DNA) floresan işaretlemesi yapılarak mikoplazma kontaminasyonu kontrolleri gerçekleştirilmiştir. Hücre hatlarından DNA izolasyonları yapılmış, elde edilen DNA örneklerinden sitokrom B (CYTB) geninin bölgesel amplifikasyonu için L14816 ve H15173 primerleri; sitokrom oksidaz alt birim I (COI) geni için ise LCO 1490 and HCO 2198 primerleri kullanılmıştır. İlgili amplifikasyonların DNA dizi analiz sonuçları, biyoinformatik araçlar kullanılarak referans dizilerle karşılaştırmalı olarak değerlendirilmiştir.Bulgular: Çalışmada ilgili hücrelerin, Bisbenzimid (Hoechst 33258) ile üretici firmanın protokollerine göre belirlenen konsantrasyon ve sürede yapılan boyama sonucunda mikoplazma kontaminasyonuna rastlanılmamıştır. Ayrıca CYTB gen bölgesi için veritabanında yer alan referans dizi ile yapılan karşılaştırma sonucu HL-60 için %97; "HeLa, L929, MDCK, Neuro-2a” hücre hatları için ise %98 oranında benzerlik bulunmuştur. COI gen bölgesi için ise bu benzerlik oranları “HeLa, HL-60, L929, MDCK ve Neuro-2a” hücre hatları için sırasıyla %95, %99, %96, %96 ve %98 olarak bulunmuştur.Sonuç: Bu bağlamda, çalışmadan elde edilen Bisbenzimid (Hoechst 33258) işaretleme ve DNA dizi analiz sonuçları, pek çok araştırmada kullanılan bu hücre hatlarının kalitesi konusunda kabul edilebilir bir belirteç ve güven sağlamıştır.   

Characterization of the Blood-Feeding Patterns of Culex quinquefasciatus (Diptera: Culicidae) in San Bernardino County, California

West Nile virus (WNV) is a zoonotic disease that is endemic in North America and is known to cause a range of symptoms from mild to life threatening in humans. Culex quinquefasciatus is one of the most prominent vectors of WNV in Southern California. The goal of this study was to identify which animal species are most fed upon by these mosquitoes in various habitats in the West Valley area of San Bernardino County, California, and determine the relationship between blood-feeding patterns and WNV activity in the region. Culex quinquefasciatus specimens were collected by West Valley Mosquito and Vector Control District during 2011 from 32 different sites. The bloodmeals of 683 individuals (92.4% of those tested) were identified using the mitochondrial gene cytochrome c oxidase 1 (COI). These bloodmeals comprised 29 vertebrate species across four different habitats. Species richness (ranging from 10 to 17) was not significantly different between habitats when rarified to account for sample size. Across habitats, the highest percentage of avian bloodmeals were taken from house sparrows (18.8-39.1%) and house finches (2.6-31.5%). Bloodmeals were identified from five mammalian species, accounting for 5.1-59.2% of bloodmeals by habitat, including humans (0-4.1%). A seasonal shift towards increased mammalian bloodmeal prevalence, specifically for domestic dog and human bloodmeals, was observed in urban habitats. The WNV activity during 2011 in San Bernardino County occurred mostly in urban and suburban areas as indicated by minimum infection rate (MIR) in Culex quinquefasciatus, notable as all human bloodmeals were identified from these two habitats.

Comparative Mitogenomics of Flesh Flies: Implications for Phylogeny

Flesh flies (Diptera: Sarcophagidae) represent a rapid radiation belonging to the Calyptratae. With more than 3000 known species, they are extraordinarily diverse in terms of their breeding habits and are therefore of particular importance in human and veterinary medicine, forensics, and ecology. To better comprehend the phylogenetic relationships and evolutionary characteristics of the Sarcophagidae, we sequenced the complete mitochondrial genomes of five species of flesh flies and performed mitogenomic comparisons amongst the three subfamilies. The mitochondrial genomes match the hypothetical condition of the insect ancestor in terms of gene content and gene arrangement. The evolutionary rates of the subfamilies of Sarcophagidae differ significantly, with Miltogramminae exhibiting a higher rate than the other two subfamilies. The monophyly of the Sarcophagidae and each subfamily is strongly supported by phylogenetic analysis, with the subfamily-level relationship inferred as (Sarcophaginae, (Miltogramminae, Paramacronychiinae)). This study suggests that phylogenetic analysis based on mitochondrial genomes may not be appropriate for rapidly evolving groups such as Miltogramminae and that the third-codon positions could play a considerable role in reconstructing the phylogeny of Sarcophagidae. The protein-coding genes ND2 and ND6 have the potential to be employed as DNA markers for species identification and delimitation in flesh flies.

Linking large-scale genetic structure of three Argynnini butterfly species to geography and environment

Understanding which factors and processes are associated with genetic differentiation within and among species remains a major goal in evolutionary biology. To explore differences and similarities in genetic structure and its association with geographical and climatic factors in sympatric sister species, we conducted a large‐scale (>32° latitude and >36° longitude) comparative phylogeographical study on three Argynnini butterfly species (Speyeria aglaja, Fabriciana adippe and F. niobe) that have similar life histories, but differ in ecological generalism and dispersal abilities. Analyses of nuclear (ddRAD‐sequencing derived SNP markers) and mitochondrial (COI sequences) data revealed differences between species in genetic structure and how genetic differentiation was associated with climatic factors (temperature, solar radiation, precipitation, wind speed). Geographical proximity accounted for much of the variation in nuclear and mitochondrial structure and evolutionary relationships in F. adippe and F. niobe, but only explained the pattern observed in the nuclear data in S. aglaja, for which mitonuclear discordance was documented. In all species, Iberian and Balkan individuals formed genetic clusters, suggesting isolation in glacial refugia and limited postglacial expansion. Solar radiation and precipitation were associated with the genetic structure on a regional scale in all species, but the specific combinations of environmental and geographical factors linked to variation within species were unique, pointing to species‐specific responses to common environments. Our findings show that the species share similar colonization histories, and that the same ecological factors, such as niche breadth and dispersal capacity, covary with genetic differentiation within these species to some extent, thereby highlighting the importance of comparative phylogeographical studies in sympatric sister species.

Establishment and characterization of a continuous cell line from caudal fin of Labeo calbasu (Hamilton, 1822)

Labeo calbasu is an important food fish and candidate species for diversification of carp aquaculture. In the present study, we have established a continuous cell line, designated as L. calbasu fin (LCF), from caudal fin of L. calbasu using explant method. The cell line has been subcultured for over 73 passages and the LCF cells show optimal growth in Leibovitz's L-15 medium supplemented with 20% fetal bovine serum at a temperature of 28°C. In karyotype analysis, the modal chromosome number of LCF cells at 35th passage was found to be 50. The amplification and sequencing of partial fragments of mitochondrial genes, namely 16S rRNA and COI from LCF cells confirmed the origin of cell line from L. calbasu. The LCF cells could be successfully transfected with GFP reporter gene, indicating suitability of these cells for expression of foreign genes. Further, following inoculation with supernatant from Tilapia lake virus (TiLV) infected cell line, no cytopathic effects were observed in the LCF cells and cell pellet was negative for TiLV in RT-PCR, indicating that LCF cells were not susceptible to TiLV. The developed cell line has been submitted to National Repository of Fish Cell Lines being maintained at ICAR-National Bureau of Fish Genetic Resources, Lucknow (accession no. NRFC063). The newly developed LCF cell line would be helpful in investigating diseases affecting this candidate species particularly the ones suspected to be of viral etiology, and for cytotoxicity and transgenic studies.

Development and characterization of a new gill cell line from the striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878)

Cell lines as an in vitro model developed from different target organs of fish find their use in virus susceptibility, cytotoxicity, gene expression studies. The striped catfish, Pangasianodon hypophthalmus, is one of the main species in aquaculture, especially in Southeast Asian countries like Thailand, Indonesia, China, India, Bangladesh, and Vietnam. The present study reports the development of a new permanent cell line from the gills of P. hypophthalmus designated as PHG and its application in toxicological research. Leibovitz's L-15 cell culture medium supplemented with 15% fetal bovine serum (FBS) was used to maintain cell line PHG. The morphology of the PHG cell line was observed fibroblastic-like. PHG cells grew well at varying temperatures ranging from 24 to 30 °C with an optimum temperature of 28 °C. The PHG cell line was characterized using a sequence of mitochondrial cytochrome C oxidase subunit I, which authenticated the species of origin of the cell line. The cell line was transfected with a pEGFP-C1 plasmid, and the transfection reporter gene was successfully expressed 48 h post-transfection with 9% transfection efficiency. The toxicity assessment of two organophosphate pesticides, chlorpyrifos, and malathion using the PHG cell line revealed that the two organophosphate pesticides were cytotoxic to the cell line at varying concentrations.

Role and relevance of fish cell lines in advanced in vitro research

Introduction

Cell line derived from fish has been established as a promising tool for studying many key issues of aquaculture covering fish growth, disease, reproduction, genetics, and biotechnology. In addition, fish cell lines are very useful in vitro models for toxicological, pathological, and immunological studies. The easier maintenance of fish cell lines in flexible temperature regimes and hypoxic conditions make them preferable in vitro tools over mammalian cell lines. Great excitement has been observed in establishing and characterizing new fish cell lines representing diverse fish species and tissue types. The well-characterized and authenticated cell lines are of utmost essential as these represent cellular functions very similar to in vivo state of an organism otherwise it would affect the reproducibility of scientific research.

Conclusion

The fish cell lines have exhibited encouraging results in several key aspects of in vitro research in aquaculture including virology, nutrition and metabolism, production of vaccines, and transgenic fish production. The review paper reports the cell lines developed from fish, their characterization, and biobanking along with their potential applications and challenges in in vitro research.

Development and characterization of five novel cell lines from snubnose pompano, Trachinotus blochii (Lacepede, 1801), and their application in gene expression and virological studies

Five novel permanent cell lines have been established from gill, heart, kidney, eye and fin of snubnose pompano, Trachinotus blochii. They were designated as snubnose pompano gill (SPG), snubnose pompano heart (SPH), snubnose pompano kidney (SPK), snubnose pompano eye (SPE) and snubnose pompano fin (SPF), respectively. All these cell lines were characterized and cryopreserved successfully at different passage levels. Cell lines were passaged every alternate day; SPG, SPH, SPK, SPE and SPF cell lines attained passage levels of 68, 74, 82, 79 and 106, respectively, since the initiation of their development in 2019. The cell lines grew well in Leibovitz's 15 medium containing 15% foetal bovine serum at 28°C. Immunophenotyping of the cell lines revealed the presence of fibronectin and pancytokeratin. No mycoplasma contamination was found. The transfection study revealed the gene expression efficiency of these cell lines by expressing the green fluorescent protein (GFP). The authentication on origin of cell lines from T. blochii was confirmed by amplification of species-specific mitochondrial cytochrome oxidase I gene. The results showed the susceptibility of these cell lines to fish nodavirus (FNV) and tilapia lake virus (TiLV) and resistance to cyprinid herpesvirus 2 (CyHV-2). The FNV infection in the cell lines was confirmed by RT-PCR, Western blot, ELISA and immunocytochemistry, while TiLV infection was confirmed by RT-PCR assay. These results revealed that these cell lines are suitable for virological and foreign gene expression studies.

The therapeutic potential of adipose tissue-derived mesenchymal stromal cells in the treatment of busulfan-induced azoospermic mice

PURPOSE

The generation of germ cells from mesenchymal stromal cells (MSCs) provides a valuable in vitro platform for infertility modeling. The establishment of these cells is a new approach for assisted reproductive technology (ART) to help infertile patients who lack functional gametes.

METHODS

Human adipose-derived MSCs were isolated and then characterized for multipotency by flow cytometry, differentiation capacity, and cytogenetic assays. These cells were used in a male germ cell differentiation study. The expression of male germ cell markers was evaluated at day 21 of differentiation using an immunofluorescence assay, flow cytometry, and RT-qPCR. Undifferentiated MSCs were used for transplantation in busulfan-induced azoospermic mice.

RESULTS

In this study, MSCs were successfully isolated from human adipose tissues which were positive for cell markers such as CD90, CD105, CD73, and CD29 but negative for CD34 and CD45. The results of flow cytometry, immunocytochemistry, and RT-qPCR analysis at day 21 of differentiation showed that the undifferentiated adipose-derived MSCs are able to differentiate into male germ cells. Additionally, transplantation of undifferentiated MSCs in busulfan-induced azoospermic mice caused spermatogenesis recovery in the majority of seminiferous tubules.

CONCLUSION

In this study, we showed that differentiation of human adipose-derived MSCs into male germ cells is a useful tool for in vitro study of human germ cell development. Our results demonstrated that cell therapy with adipose-derived MSCs could help the repair of pathological changes in testicular seminiferous tubules. Therefore, it may have a clinical application for the treatment of azoospermia in infertile patients.

Best Practices for Authentication of Cell Lines to Ensure Data Reproducibility and Integrity

Cell line misidentification and contamination are major contributors to the reproducibility crisis in academic research. Authentication of cell lines provides assurances of the data generated; however, commercially available cells are often not subjected to rigorous identification testing. In this study, commercially available cell lines underwent testing to confirm cell identity and purity. The methods reported here outline the best practices for cell line authentication. Briefly, a commercially available primary rabbit aortic endothelial cell line was purchased for the intent of producing target proteins necessary for generating species-specific recombinant antibodies. These rabbit-specific antibodies would then be utilized for the development of in-house enzyme-linked immunosorbent assays (ELISA) to evaluate blood-based biomarkers of vascular injury after total-body irradiation. To authenticate the cell line, cell identity and purity were determined by single tandem repeat (STR) testing, flow cytometry, polymerase chain reaction (PCR), and cytochrome c oxidase subunit 1 (CO1) DNA Barcoding in-house and/or through commercial vendors. Fresh cells obtained from a New Zealand White rabbit (Charles River, Wilmington, DE) were used as a positive control. The results of STR and flow cytometry analyses indicated the cells were not contaminated with human or mouse cells, and that the cells were not of endothelial origin. PCR demonstrated that cells were also not of rabbit origin, which was further confirmed by a third-party vendor. An unopened vial of cells was submitted to another vendor for CO1 DNA Barcoding analysis, which identified the cells as being purely of bovine origin. Results revealed that despite purchase through a commercial vendor, the cell line marketed as primary rabbit aortic endothelial cells were of bovine origin. Purity analysis found cells were misidentified rather than contaminated. Further investigation to determine the cell type was not performed. The most cost-effective and efficient methodology for confirming cell line identity was found to be CO1 DNA Barcoding performed by a commercial vendor.

In vitro functional genetic modification of canine adenovirus type 2 genome by CRISPR/Cas9

Genetically modified oncolytic adenoviruses have been proposed as a vehicle for cancer therapy. However, several concerns, such as toxicity to normal cells and organs, lack of suitable cell surface receptors to allow viral entry to the desired cell type(s), and activation of both innate and adaptive immune systems in patients, restrict the successful clinical application of adenoviral-mediated cancer gene therapy. Successful virotherapy will require efficient transductional and transcriptional targeting to enhance therapeutic efficacy by ensuring targeted adenoviral infection, replication, and/or therapeutic transgene expression. Targeted modification of viral components, such as viral capsid, fiber knob, and the insertion of transgenes for expression, are prerequisites for the necessary transductional and transcriptional targeting of adenovirus. However, the conventional approach to modify the adenoviral genome is complex, time consuming, and expensive. It is dependent on the presence of unique restriction enzyme sites that may or may not be present in the target location. Clustered regularly interspaced short palindromic repeat (CRISPR) along with the RNA-guided nuclease Cas9 (CRISPR/Cas9) is one of the most powerful tools that has been adopted for precise genome editing in a variety of cells and organisms. However, the ability of the CRISPR/Cas9 system to precisely and efficiently make genetic modification, as well as introduce gene replacements, in adenoviral genomes, remains essentially unknown. Herein the ability of in vitro CRISPR/CAS9-mediated editing of the canine adenovirus type 2 (CAV2) genome to promote targeted modification of the viral genome was assessed. To demonstrate the feasibility of this goal, CRISPR/Cas9 has been used to successfully insert the RFP (red fluorescent protein) reporter construct into the CAV2 genome. Initial results demonstrated high efficiency and accuracy for in vitro CRISPR-mediated editing of the large CAV2 genome. Furthermore, this application was expanded, using multiple guide RNAs, to conduct gene replacement in the CAV2 genome by substituting a portion of the E3 gene with a construct designed to express a single chain antibody to canine PD-1. Thus, this work provides a significantly improved and efficient method for targeted editing of adenoviruses to generate altered and potentially therapeutic viral genomes in the shortest possible time.

Visualizing the cancer stem-like properties of canine tumour cells with low proteasome activity

Cancer stem-like cells (CSCs) cause treatment failure in various tumours; however, establishing CSC-targeted therapies has been hampered by difficulties in the identification and isolation of this small sub-population of cells. Recent studies have revealed that tumour cells with low proteasome activity display a CSC phenotype that can be utilized to image CSCs in canines. This study visualizes and reveals the CSC-like properties of tumour cells with low proteasome activity in HMPOS (osteosarcoma) and MegTCC (transitional cell carcinoma), which are canine cell lines. The parent cells were genetically engineered to express ZsGreen1, a fluorescent protein connected to the carboxyl-terminal degron of canine ornithine decarboxylase that accumulates with low proteasome activity (ZsG⁺ cells). ZsG⁺ cells were imaged and the mode of action of this system was confirmed using a proteasome inhibitor (MG-132), which increased the ZsGreen1 fluorescence intensity. The CSC-like properties of ZsG⁺ cells were evaluated on the basis of cell divisions, cell cycle, the expression of CSC markers and tumourigenicity. ZsG⁺ cells underwent asymmetric divisions and had a low percentage of G0/G1 phase cells; moreover, ZsG⁺ cells expressed CSC markers such as CD133 and showed a large tumourigenic capability. In histopathological analysis, ZsG⁺ cells were widely distributed in the tumour samples derived from ZsG⁺ cells and in the proliferative regions of the tumours. The results of this study indicate that visualized canine tumour cells with low proteasome activity have a CSC-like phenotype and that this visualization system can be utilized to identify and isolate canine CSCs.

Immune pathways and TP53 missense mutations are associated with longer survival in canine osteosarcoma

Osteosarcoma affects about 2.8% of dogs with cancer, with a one-year survival rate of approximately 45%. The purpose of this study was to characterize mutation and expression profiles of osteosarcoma and its association with outcome in dogs. The number of somatic variants identified across 26 samples ranged from 145 to 2,697 with top recurrent mutations observed in TP53 and SETD2. Additionally, 47 cancer genes were identified with copy number variations. Missense TP53 mutation status and low pre-treatment blood monocyte counts were associated with a longer disease-free interval (DFI). Patients with longer DFI also showed increased transcript levels of anti-tumor immune response genes. Although, T-cell and myeloid cell quantifications were not significantly associated with outcome; immune related genes, PDL-1 and CD160, were correlated with T-cell abundance. Overall, the association of gene expression and mutation profiles to outcome provides insights into pathogenesis and therapeutic interventions in osteosarcoma patients.

Cryopreservation of Iranian Markhoz goat fibroblast cells as an endangered national genetic resource

Background

The continuous accessibility of local animals for sustainable use is being eroded annually. Thus, a strategic vision for the conservation of biodiversity is of far-reaching emphasis to deal with unprecedented challenges in the local population extension facing in the future. This study aimed to establish and cryopreserve endangered Markhoz goat (Capra hircus) fibroblast cell lines in vitro.

Methods and results

These primary fibroblast cells were isolated from 58 Iranian Markhoz goats and individually cultured by explant technique in DMEM medium supplemented with 10% FBS and 2 mM L-Glutamine, in the presence of Penicillin (200 U/ml)—Streptomycin (200 mg/ml) during the first passage number. The extracted cell lines were confirmed morphologically as fibroblast cells. The population doubling time for DMEM-cultured cells was 23 ± 0.5 h. Chromosomal analysis indicated a total chromosome number of 2n = 60 with > 95% frequency. The cultured cells were checked for bacteria, fungi, yeast, and mycoplasma contaminations and the results were reported negative. The efficiencies of the fluorescent protein encoded by VSV-G (pMDG) and lentiviral pCSGW vectors reported in a range of 65% value. According to the species identification analysis, the goat cell lines were banked and confirmed without any miss- and cross-contamination.

Conclusions

The significant issue in this paper can be concluded about the first report of the establishment of endangered Markhoz goat cell banking inside the country. This study demonstrated the successful establishment of a genetically stable fibroblast bank as a valuable genetic resource for the endangered Iranian Markhoz goat breed.

Mosquito blood-feeding patterns and nesting behavior of American crows, an amplifying host of West Nile virus

Background

Although American crows are a key indicator species for West Nile virus (WNV) and mount among the highest viremias reported for any host, the importance of crows in the WNV transmission cycle has been called into question because of their consistent underrepresentation in studies of Culex blood meal sources. Here, we test the hypothesis that this apparent underrepresentation could be due, in part, to underrepresentation of crow nesting habitat from mosquito sampling designs. Specifically, we examine how the likelihood of a crow blood meal changes with distance to and timing of active crow nests in a Davis, California, population.

Methods

Sixty artificial mosquito resting sites were deployed from May to September 2014 in varying proximity to known crow nesting sites, and Culex blood meal hosts were identified by DNA barcoding. Genotypes from crow blood meals and local crows (72 nestlings from 30 broods and 389 local breeders and helpers) were used to match mosquito blood meals to specific local crows.

Results

Among the 297 identified Culex blood meals, 20 (6.7%) were attributable to crows. The mean percentage of blood meals of crow origin was 19% in the nesting period (1 May–18 June 2014), but 0% in the weeks after fledging (19 June–1 September 2014), and the likelihood of a crow blood meal increased with proximity to an active nest: the odds that crows hosted a Culex blood meal were 38.07 times greater within 10 m of an active nest than > 10 m from an active nest. Nine of ten crow blood meals that could be matched to a genotype of a specific crow belonged to either nestlings in these nests or their mothers. Six of the seven genotypes that could not be attributed to sampled birds belonged to females, a sex bias likely due to mosquitoes targeting incubating or brooding females.

Conclusion

Data herein indicate that breeding crows serve as hosts for Culex in the initial stages of the WNV spring enzootic cycle. Given their high viremia, infected crows could thereby contribute to the re-initiation and early amplification of the virus, increasing its availability as mosquitoes shift to other moderately competent later-breeding avian hosts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04827-x.

Structural features and phylogenetic implications of Cicadellidae subfamily and two new mitogenomes leafhoppers

Complete mitochondrial genome sequences facilitate species identification and analyses of phylogenetic relationships. However, the available data are limited to the diverse and widespread insect family Cicadellidae. This study analyzes and summarizes the complete mitochondrial genome structure characteristics of 11 leafhopper subfamilies and two newly sequenced Typhlocybinae species, Empoascanara wengangensis and E. gracilis. Moreover, using 13PCGs and rRNA data to analyze the nucleotide diversity, evolution rate, and the phylogenetic relationship between the subfamilies of 56 species, verifying the taxonomic status analysis of E. wengangensis and E. gracilis. The analysis results show that the genome structures of the subfamilies and the newly sequenced two species are very similar, and the size of the CR region is significantly related to the repeat unit. However, in the entire AT-skews and CG-skews, the AT-skews of other subfamilies are all positive, and CG-skews are negative, while Empoascini of Typhlocybinae and Ledrinae are the opposite. Furthermore, among 13PCGs, the AT-skews of 13 species are all negative while CG-skews are positive, which from Empoascini in Typhlocybinae, Idiocerinae, Cicadellinae, Ledrinae, and Evacanthinae. Phylogenetic analysis shows that ML and PB analysis produce almost consistent topologies between different data sets and models, and some relationships are highly supported and remain unchanged. Mileewinae is a monophyletic group and is a sister group with Typhlocybinae, and the sister group of Evacanthinae is Ledrinae + Cicadellinae. Phylogenetic analysis grouped the two newly sequenced species with other species of Typhlocybinae, which was separated from other subfamilies, and all Erythroneurini insects gathered together. However, E. gracilis grouped into a single group, not grouped with species of the same genus (Empoascanara). This result does not match the traditional classification, and other nuclear genes or transcriptome genes may be needed to verify the result. Nucleotide diversity analysis shows that nad4 and nad5 may be evaluated as potential DNA markers defining the Cicadellidae insect species.

Analysis of endogenous and exogenous tumor upregulated promoter expression in canine tumors

Gene therapy is a promising treatment option for cancer. However, its utility may be limited due to expression in off-target cells. Cancer-specific promoters such as telomerase reverse transcriptase (TERT), survivin, and chemokine receptor 4 (CXCR4) have enhanced activity in a variety of human and murine cancers, however, little has been published regarding these promoters in dogs. Given the utility of canine cancer models, the activity of these promoters along with adenoviral E2F enhanced E1a promoter (EEE) was evaluated in a variety of canine tumors, both from the endogenous gene and from exogenously administered constructs. Endogenous expression levels were measured for cTERT, cSurvivin, and cCXCR4 and were low for all three, with some non-malignant and some tumor cell lines and tissues expressing the gene. Expression levels from exogenously supplied promoters were measured by both the number of cells expressing the construct and the intensity of expression in individual cells. Exogenously supplied promoters were active in more cells in all tumor lines than in normal cells, with the EEE promoter being most active, followed by cTERT. The intensity of expression varied more with cell type than with specific promoters. Ultimately, no single promoter was identified that would result in reliable expression, regardless of the tumor type. Thus, these findings imply that identification of a pan-cancer promoter may be difficult. In addition, this data raises the concern that endogenous expression analysis may not accurately predict exogenous promoter activity.

Temporal activation of LRH-1 and RAR-γ in human pluripotent stem cells induces a functional naïve-like state

Naïve pluripotency can be established in human pluripotent stem cells (hPSCs) by manipulation of transcription factors, signaling pathways, or a combination thereof. However, differences exist in the molecular and functional properties of naïve hPSCs generated by different protocols, which include varying similarities with pre-implantation human embryos, differentiation potential, and maintenance of genomic integrity. We show here that short treatment with two chemical agonists (2a) of nuclear receptors, liver receptor homologue-1 (LRH-1) and retinoic acid receptor gamma (RAR-γ), along with 2i/LIF (2a2iL) induces naïve-like pluripotency in human cells during reprogramming of fibroblasts, conversion of pre-established hPSCs, and generation of new cell lines from blastocysts. 2a2iL-hPSCs match several defined criteria of naïve-like pluripotency and contribute to human-mouse interspecies chimeras. Activation of TGF-β signaling is instrumental for acquisition of naïve-like pluripotency by the 2a2iL induction procedure, and transient activation of TGF-β signaling substitutes for 2a to generate naïve-like hPSCs. We reason that 2a2iL-hPSCs are an easily attainable system to evaluate properties of naïve-like hPSCs and for various applications.

Development and characterization of a new DRCF cell line from Indian wild strain zebrafish Danio rerio (Hamilton 1822)

Danio rerio, zebrafish, has been widely used as a non-mammalian vertebrate model organism in various studies. The present research describes to develop and characterize a new cell line from a wild strain Indian zebrafish native to Brahmaputra River, Assam, India. The new cell line designated as DRCF was developed from the caudal fin of D. rerio. The cell line was successfully subcultured up to 31 passages. Growth studies revealed that cell growth of DRCF was optimal at 28 °C in L-15 medium supplemented with 20% FBS. Molecular characterization of the DRCF cell line using mitochondrial genes namely cytochrome oxidase subunit I gene (COI) and 16S rRNA authenticated the true origin of the cell line. The chromosome analysis of the DRCF cell line expressed its 50 diploid chromosome number of D. rerio. The immunocytochemical characterization of the cell line exhibited its fibroblastic morphology. The expression of the green fluorescent protein (GFP) following transfection revealed the suitability of the cell line for transfection studies.

DNA barcoding for identification of fish species from freshwater in Enugu and Anambra States of Nigeria

Within Enugu and Anambra States, Nigeria, identification of fishes has been based on morphological traits and do not account for existing biodiversity. For DNA barcoding, assessment of biodiversity, conservation and fishery management, 44 fish sampled from Enugu and Anambra States were isolated, amplified and sequenced with mitochondrial cytochrome oxidase subunit I (COI). Twenty groups clustering at 100% bootstrap value including monophyletic ones were identified. The phylogenetic diversity (PD) ranged from 0.0397 (Synodontis obesus) to 0.2147 (Parachanna obscura). The highest percentage of genetic distance based on Kimura 2-parameter was 37.00 ± 0.0400. Intergeneric distances ranged from 15.8000 to 37.0000%. Congeneric distances were 6.9000 ± 0.0140–28.1000 ± 0.0380, with Synodontis as the existing synonymous genus. Confamilial distances in percentage were 16.0000 ± 0.0140 and 25.7000 ± 0.0300. Forty-two haplotypes and haplotype diversity of 0.9990 ± 0.0003 were detected. Nucleotide diversity was 0.7372, while Fu and Li’s D* test statistic was 2.1743 (P < 0.02). Tajima’s D was 0.2424 (P > 0.10) and nucleotide frequencies were C (17.70%), T (29.40%), A (24.82%), G (18.04%) and A + T (54.22%). Transitional mutations were more than transversions. Twenty species (99–100%) were identified with the e-value, maximum coverage and bit-score of 1e−43, 99–100 and 185–1194, respectively. Seventeen genera and 12 families were found and Clariidae (n = 14) was the most dominant among other families. The fish species resolution, diversity assessment and phylogenetic relationships were successfully obtained with the COI marker. Clariidae had the highest number of genera and families. Phylogenetic diversity analysis identified Parachanna obscura as the most evolutionarily divergent one. This study will contribute to fishery management, and conservation of freshwater fishes in Enugu and Anambra States, Nigeria.

Establishment and Preservation of Lymphoblastoid Cell Lines from Fresh and Frozen Whole Blood and Mononuclear Cells

Although blood cells are interesting sources for genome investigations, one of the main problems in obtaining genomic DNA from blood is the restricted amount of DNA. This obstacle can be avoided by generating Epstein-Barr virus (EBV)-induced B cell lines. This study investigates the efficiency of four different methods to generate lymphoblastoid cell lines (LCLs). Blood samples (n = 120) were obtained from donors and categorized into four groups: fresh whole blood, frozen whole blood, fresh peripheral blood mononuclear cells (PBMCs), and frozen PBMCs. The samples were followed by EBV transformation to generate LCLs. Quality control and authentication of the cells were performed using multiplex PCR and short tandem repeat (STR) analyses. Finally, we assessed the success rate and amount of time to establish the cell lines in each group. The results showed that the cells were not contaminated nor were they misidentified or cross-contaminated with other cells. The success rate of LCLs generated from the whole blood groups was lower than the PBMC groups. The freezing procedures did not have any considerable effect on the establishment of lymphoblastoid cells. These established cells have been preserved in the human and animal cell bank of the Iranian Biological Resource Center (IBRC) and are available for researchers. Due to the management and transformation of a substantial number of blood samples, we recommend that researchers freeze PBMCs for further use with high efficiency and time-saving. We suggest that whole fresh blood should be directly transformed when the volume of the blood sample is less than 0.5 ml.

Establishment and characterization of novel cell lines derived from six lepidopteran insects collected in the field

Insect cell lines are used to study cellular interactions and gene functions in vitro in several research areas. However, suitable cell lines for experiments are not always available, especially in non-model species. Here, we established novel cell lines derived from fat bodies of six lepidopteran insects: Cydia kurokoi (named NARO-Cyku), Cephonodes hylas (NARO-Cehy), Haritalodes basipunctalis (NARO-Haba), Theretra oldenlandiae (NARO-Thol), Lymantria dispar (NARO-Lydi), and Hyphantria cunea (NARO-Hycu) collected in the field. The larval fat body was a promising tissue for the starting material when samples were limited due to field collection. It was critical that the medium volume was kept to a minimum for primary culture to maintain adherence of the fat body cells to the flask. The flask was coated with poly-L-lysine for effective induction of adherence and cell division. The identities of cell lines were confirmed using DNA barcoding with the mitochondrial cytochrome c oxidase I gene after cultures were passaged over 50 times. All lines except for NARO-Lydi and NARO-Hycu are adherent cells, and population doubling time of six cell lines ranged from 1.03 to 2.49. Induction of gene expression was practicable in the four adherent cell lines as revealed by transfection of expression vectors and found the immediate early 2 and the Bombyx actin 3 were effective gene promoters. The results suggest that these cell lines are capable of gene functional analysis. Thus, establishments of cell line using our methods for non-model lepidopterans could make a practical contribution to pest management and insect utilization.

From the Clinic to the Bench and Back Again in One Dog Year: How a Cross-Species Pipeline to Identify New Treatments for Sarcoma Illuminates the Path Forward in Precision Medicine

Cancer drug discovery is an inefficient process, with more than 90% of newly-discovered therapies failing to gain regulatory approval. Patient-derived models of cancer offer a promising new approach to identify new treatments; however, for rare cancers, such as sarcomas, access to patient samples is limited, which precludes development of patient-derived models. To address the limited access to patient samples, we have turned to pet dogs with naturally-occurring sarcomas. Although sarcomas make up <1% of all human cancers, sarcomas represent 15% of cancers in dogs. Because dogs have similar immune systems, an accelerated pace of cancer progression, and a shared environment with humans, studying pet dogs with cancer is ideal for bridging gaps between mouse models and human cancers. Here, we present our cross-species personalized medicine pipeline to identify new therapies for sarcomas. We explore this process through the focused study of a pet dog, Teddy, who presented with six synchronous leiomyosarcomas. Using our pipeline we identified proteasome inhibitors as a potential therapy for Teddy. Teddy was treated with bortezomib and showed a varied response across tumors. Whole exome sequencing revealed substantial genetic heterogeneity across Teddy's recurrent tumors and metastases, suggesting that intra-patient heterogeneity and tumoral adaptation were responsible for the heterogeneous clinical response. Ubiquitin proteomics coupled with exome sequencing revealed multiple candidate driver mutations in proteins related to the proteasome pathway. Together, our results demonstrate how the comparative study of canine sarcomas offers important insights into the development of personalized medicine approaches that can lead to new treatments for sarcomas in both humans and canines.

Isoenzyme and molecular approach for authenticating and monitoring of animal cell lines

Authentication of cell lines is of paramount importance to validate the results from their use in biomedical research. Although isoenzyme polymorphism is the standard method, molecular methods based on mitochondrial DNA (mtDNA) have been developed to replace it. The aim of this study was the improvement of our isoenzyme electrophoretic analysis and the validation of one molecular technique targeted at mtDNA for the authentication of our animal cell lines. The combined method of cellular lysing through osmotic shock, followed by freezing-thawing in N2 to obtain isoenzyme extracts, and with 42 × 106 cells maintained the best efficiency. The superior electrophoretic conditions were PAGE run at 200 V. All cell lines had isoenzymatic mobility corresponding to their species to lactate dehydrogenase, malate-dehydrogenase, and glucose-6-phosphate dehydrogenase isoenzymes, and could be distinguished from each other. Two molecular techniques based on mtDNA were tested, one on the cytochrome b gene and other on cytochrome c oxidase I subunit gene. Due to difficulties in distinguishing all cell lines using only one these techniques, we merged the primers of two methods in such a way that there was a sufficient differentiation of all DNA fragments. The sequencing of these PCR products was also performed to validate these data.

Development of conventional and real time PCR assays for rapid species authentication of mammalian cell lines commonly used in veterinary diagnostic laboratories

Mammalian cell lines are valuable tools in biomedical fields, with applications ranging from disease diagnosis to the production of biological reagents and vaccines. Here we report the development of new conventional (cPCR) and real time PCR (qPCR) assays for species identification of several mammalian kidney cell lines originated from swine, green monkey, hamster and bovine tissues that are extensively used in veterinary diagnostic laboratories. The PCR primers and probes were selected from highly conserved mitochondrial genes and analyzed in silico by nucleotide BLAST in the National Center for Biotechnology Information (NCBI) website to ensure target specificity. The assays were highly species-specific and had no cross-reactivity against other tested cell lines originated from different mammalian species. Assay sensitivity (limit of detection; LOD) was determined using serial dilutions of cell line DNA as template. The estimated LODs were between 2.95 and 48 pg (picogram) DNA/assay for cPCR, and between 1.5 × 10^-3 and 4.8 × 10^-2 pg DNA/assay for qPCR. Multiplex qPCR assays were developed for simultaneous detection of up to three species in a single assay. The multiplex qPCR assays exhibited the same sensitivity as the corresponding singleplex assays with the exception of the green monkey species that demonstrated a 10-100 fold decline in the sensitivity. Contamination of swine cells was detected in one of the rabbit cell lines. The contamination was further confirmed by Sanger and Next-Generation sequencing.

Complete mitochondrial genomes of Bittacus strigosus and Panorpa debilis and genomic comparisons of Mecoptera

Mitochondrial genomes play a significant role in reconstructing phylogenetic relationships and revealing molecular evolution of insects. However, only four mitochondrial genomes were reported in Mecoptera to date. Here, we obtained two new complete mitochondrial genomes of the hangingfly Bittacus strigosus Hagen, 1861 and the scorpionfly Panorpa debilis Westwood, 1846. The results show that the complete mitogenome sequences of B. strigosus and P. debilis are 15,825 and 17,018 bp, respectively, both containing 37 genes and one control region. The mecopteran mitogenomes are highly similar in A + T bias, AT-skew, and GC-skew. Tandem repeats of the control region were discovered in Mecoptera for the first time. The sliding window, genetic distance, and Ka/Ks ratio analyses indicate the purifying selection of 13 protein-coding genes, the lowest evolutionary rate of cox1, and the highest sequence variability of atp8. Considering the sufficiently large size, fast evolution, and high ratio of Ka/Ks, nad4L and nad6 are regarded as potential markers for future phylogenetic analyses, population genetics, and species delimitations in Mecoptera. The phylogenetic relationships were reconstructed for four families of Mecoptera based on all six available mitogenomes using Bayesian inference and maximum likelihood methods. The phylogeny is presented as Boreidae + (Nannochoristidae + (Bittacidae + Panorpidae)).

Interlaboratory study to validate a STR profiling method for intraspecies identification of mouse cell lines

The Consortium for Mouse Cell Line Authentication was formed to validate Short Tandem Repeat (STR) markers for intraspecies identification of mouse cell lines. The STR profiling method is a multiplex polymerase chain reaction (PCR) assay comprised of primers targeting 19 mouse STR markers and two human STR markers (for interspecies contamination screening). The goals of the Consortium were to perform an interlaboratory study to–(1) validate the mouse STR markers to uniquely identify mouse cell lines (intraspecies identification), (2) to provide a public database of mouse cell lines with the National Institute of Standards and Technology (NIST)-validated mouse STR profiles, and (3) to publish the results of the interlaboratory study. The interlaboratory study was an international effort that consisted of 12 participating laboratories representing institutions from academia, industry, biological resource centers, and government. The study was based on 50 of the most commonly used mouse cell lines obtained from the American Type Culture Collection (ATCC). Of the 50 mouse cell lines, 18 had unique STR profiles that were 100% concordant (match) among all Consortium laboratory members, and the remaining 32 cell lines had discordance that was resolved readily and led to improvement of the assay. The discordance was due to low signal and interpretation issues involving artifacts and genotyping errors. Although the total number of discordant STR profiles was relatively high in this study, the percent of labs agreeing on allele calls among the discordant samples was above 92%. The STR profiles, including electropherogram images, for NIST-validated mouse cell lines will be published on the NCBI BioSample Database (https://www.ncbi.nlm.nih.gov/biosample/). Overall, the interlaboratory study showed that the multiplex PCR method using 18 of the 19 mouse STR markers is capable of discriminating at the intraspecies level between mouse cell lines. Further studies are ongoing to refine the assay including (1) development of an allelic ladder for improving the accuracy of allele calling and (2) integration of stutter filters to identify true stutter.

Class A scavenger receptor expression and function in eight novel tadpole cell lines from the green frog (Lithobates clamitans) and the wood frog (Lithobates sylvatica)

A total of eight tadpole cell lines were established from green frogs (Lithobates clamitans) and wood frogs (Lithobates sylvatica). The five green frog cell lines were named GreenTad-HF1, GreenTad-HF2, GreenTad-HF3, GreenTad-HE4, and GreenTad-gill. The three wood frog cell lines were named WoodTad-HE1, WoodTad-Bone, and WoodTad-rpe. DNA barcoding confirmed the cell lines to be from the correct species and the growth characteristics (optimal temperature and FBS requirement) were elucidated. In order to begin studying the innate immune capacity for each cell line, class A scavenger receptor expression and function were next explored. All cell lines expressed genes for at least 3 of the 5 class A scavenger receptor (SR-A) family members, but the gene expression patterns varied between cell lines. MARCO was only expressed in GreenTad-HE4 and WoodTad-Bone, while only GreenTad-HF3 did not express SCARA5 and only WoodTad-rpe did not express SR-AI. Acetylated low density lipoprotein (AcLDL) is a well-defined ligand for SR-As and WoodTad-rpe was the only cell line to which it was unable to bind. In the other seven tadpole cell lines, the SR-A competitive ligands (dextran sulfate, fucoidan, polyinosinic acid) blocked AcLDL binding whereas the SR-A non-competitive ligand counterparts (chondroitin sulfate, fetuin, polycytidylic acid, respectively) did not. Overall, these new eight cell lines can become important tools in the study of innate immunity in general and SR-A functions in particular in green frogs and wood frogs.

Bovine leukemia virus discovered in human blood

BACKGROUND

Bovine leukemia virus (BLV) infection is widespread in cattle globally and is present in marketed beef and dairy products. Human infection with BLV has been reported in breast and lung cancer tissues and was significantly associated with breast cancer in 3 case-control studies. The purpose of this current research was to determine if BLV is present in human blood cells and if antibodies to BLV are related to blood cell infection.

METHODS

Standard liquid PCR and Sanger DNA sequencing were used to test for BLV in buffy coat cells (leukocytes and platelets) of blood specimens from 95 self-selected female subjects. Enzyme-linked immunosorbent assay (ELISA) for IgG, IgM, and IgA was used to detect antibodies to BLV in the plasma of the corresponding blood samples.

RESULTS

BLV DNA was detected in the buffy coat cells of blood in 33/95 (38%) of the subjects by PCR and DNA sequencing. IgG antibodies were detected in 30/95(32%), IgM in 55/95(58%), and IgA in 30/95(32%) of the subjects. There was no significant correlation between presence of the antibodies and presence of BLV DNA.

CONCLUSIONS

This first report of BLV in human blood raises the question of whether infection of leukocytes could conceivably lead to leukemia as it does in infected cattle. Also, system wide circulation of infected blood cells could facilitate BLV transit to various internal tissues/organs with potential for their infection and subsequent development of cancer. The most likely route of BLV transmission to humans would be zoonotic, as a foodborne infection. Although eradicated from cattle in some countries, BLV still has a high rate of infection in the Americas, the Middle East, and parts of Europe and Asia. This report of BLV in the blood layer containing human leukocytes/platelets adds important information which could be useful to elucidate possible routes of transmission of BLV to humans and to prevent further human infection.

L-WRN conditioned medium for gastrointestinal epithelial stem cell culture shows replicable batch-to-batch activity levels across multiple research teams

Conditioned medium (CM) derived from engineered cells often facilitates the cost-effective culture of a variety of stem cells. Growing emphasis on the importance of rigor and reproducibility in lab-based science requires development of best practices approaches, including quality control procedures for the assessment of CM batches to ensure reliable interpretation and reproducibility. Here, we tested activity level variations of L-WRN CM, which is produced from an L cell line engineered to secrete Wnt3a, R spondin 3, and Noggin into a single CM that is widely used for gastrointestinal stem cell culture. We assessed 14 independent batches of L-WRN CM, produced by 5 laboratories at 3 research institutions, by multiple quantitative assays. We observed highly replicable activity levels among L-WRN CM batches prepared according to a previously published protocol. Quality control assays measuring spheroid growth or mRNA gene marker expression were best able to distinguish the quality L-WRN CM batches, whereas a Wnt reporter assay did not. Thus, we have validated that L-WRN CM activity is highly reproducible over time and between laboratories and have provided guidelines for L-WRN CM quality control testing. These validation procedures and guidelines will benefit experiment replication efforts in stem cell research.

Salinomycin decreases feline sarcoma and carcinoma cell viability when combined with doxorubicin

BACKGROUND

Cancer is a significant health threat in cats. Chemoresistance is prevalent in solid tumors. The ionophore salinomycin has anti-cancer properties and may work synergistically with chemotherapeutics. The purpose of our study was to determine if salinomycin could decrease cancer cell viability when combined with doxorubicin in feline sarcoma and carcinoma cells.

RESULTS

We established two new feline injection-site sarcoma cell lines, B4 and C10, and confirmed their tumorigenic potential in athymic nude mice. B4 was more resistant to doxorubicin than C10. Dose-dependent effects were not observed until 92 μM in B4 cells (p = 0.0006) vs. 9.2 μM (p = 0.0004) in C10 cells. Dose-dependent effects of salinomycin were observed at 15 μM in B4 cells (p = 0.025) and at 10 μM in C10 cells (p = 0.020). Doxorubicin plus 5 μM salinomycin decreased viability of B4 cells compared to either agent alone, but only at supra-pharmacological doxorubicin concentrations. However, doxorubicin plus 5 μM salinomycin decreased viability of C10 cells compared to either agent alone at doxorubicin concentrations that can be achieved in vivo (1.84 and 4.6 μM, p < 0.004). In SCCF1 cells, dose-dependent effects of doxorubicin and salinomycin were observed at 9.2 (p = 0.036) and 2.5 (p = 0.0049) μM, respectively. When doxorubicin was combined with either 1, 2.5, or 5 μM of salinomycin in SCCF1 cells, dose-dependent effects of doxorubicin were observed at 9.2 (p = 0.0021), 4.6 (p = 0.0042), and 1.84 (p = 0.0021) μM, respectively. Combination index calculations for doxorubicin plus 2.5 and 5 μM salinomycin in SCCF1 cells were 0.4 and 0.6, respectively.

CONCLUSIONS

We have developed two new feline sarcoma cell lines that can be used to study chemoresistance. We observed that salinomycin may potentiate (C10 cells) or work synergistically (SCCF1 cells) with doxorubicin in certain feline cancer cells. Further research is indicated to understand the mechanism of action of salinomycin in feline cancer cells as well as potential tolerability and toxicity in normal feline tissues.

Restoration of Endogenous Retrovirus Infectivity Impacts Mouse Cancer Models

Mouse models have been instrumental in establishing fundamental principles of cancer initiation and progression and continue to be invaluable in the discovery and further development of cancer therapies. Nevertheless, important aspects of human disease are imperfectly approximated in mouse models, notably the involvement of endogenous retroviruses (ERVs). Replication-defective ERVs, present in both humans and mice, may affect tumor development and antitumor immunity through mechanisms not involving infection. Here, we revealed an adverse effect of murine ERVs with restored infectivity on the behavior of mouse cancer models. In contrast to human cancer, where infectious ERVs have never been detected, we found that ERV infectivity was frequently restored in transplantable, as well as genetic, mouse cancer models. Such replication-competent, ERV-derived retroviruses were responsible for unusually high expression of retroviral nucleic acids and proteins in mouse cancers. Infectious ERV-derived retroviruses produced by mouse cancer cells could directly infect tumor-infiltrating host immune cells and fundamentally modified the host's immune defenses to cancer, as well as the outcome of immunotherapy. Therefore, infectious retroviruses, variably arising in mouse cancer models, but not in human cancer, have the potential to confound many immunologic studies and should be considered as a variable, if not altogether avoided. Cancer Immunol Res; 6(11); 1292-300. ©2018 AACR.

Assessing off-target cytotoxicity of the field lampricide 3-trifluoromethyl-4-nitrophenol using novel lake sturgeon cell lines

Lampricides are currently being applied to streams and rivers to control the population of sea lamprey, an invasive species, in the Great Lakes. The most commonly used lampricide agent used in the field is 3-trifluoromethyl-4-nitrophenol (TFM), which targets larval sea lamprey in lamprey-infested rivers and streams. The specificity of TFM is due to the relative inability of sea lamprey to detoxify the agent relative to non-target fishes. There is increasing concern, however, about non-target effects on fishes, particularly threatened populations of juvenile lake sturgeon (LS; Acipenser fulvescens). There is therefore a need to develop models to better define lake sturgeon's response to TFM. Here we report the establishment of five LS cell lines derived from the liver, gill, skin and intestinal tract of juvenile LS and some of their cellular characteristics. All LS cell lines grew well at 25 °C in Leibovitz's (L)- 15 medium supplemented with 10% FBS. All cell lines demonstrated high senescence-associated β-galactosidase activity and varying levels of Periodic acid Schiff-positive polysaccharides, indicating substantial production of glycoproteins and mucosubstances by the cells. Comparative toxicity of TFM in the five LS cell lines was assessed by two fluorescent cell viability dyes, Alamar Blue and CFDA-AM, in conditions with and without serum and at 24 or 72 h exposure. Deduced EC₅₀ values were compared between the cell lines and to the reported in vivo LC₅₀s. Tissues sensitive to the effects of TFM in vivo correlated with cell lines from the same tissues being most sensitive to TFM in vitro. EC₅₀ values for the LSliver-e cells was significantly lower than the EC₅₀ for the rainbow trout (RBT) liver cells RTL-W1, reaffirming the in vivo observation that LS was generally more TFM-sensitive than rainbow trout. Our data suggests that whole-fish sensitivity of LS to TFM is likely attributable to sensitivity at the cellular level. Thus, LS cell lines, as well as those of RBT, can be used to screen and evaluate the toxicity of the next generation of lampricides on non-target fish such as lake sturgeon.

Establishment and characterization of rough-tailed gecko original tail cells

Some of lizard species have the ability to lose their tail in order to defend against predators and regenerate the new tail. Lizard's regenerated tail has attracted scientists' attention for unraveling the regeneration process, but less information is known about the cellular characterization and cell growth properties of original tail. This research aimed to report cell culture and banking process of rough-tailed gecko or Cyrtopodion scabrum's original tail cell sample from inner tissue without skin using tissue explant technique. For banking reports, it is essential to analyze this cells' potential to proliferate, to investigate biological aspects such as cell culture features, differentiation and chromosome number and to report its species identification and quality control. To achieve optimal growth conditions, three different temperatures for incubation including 18, 23 and 37 °C and two different media including DMEM and L-15 were applied. The expanded cells were studied for their potential to adipose and osteoblast differentiation. Results indicated that lizard's original tail cells could be successfully obtained by explant technique. The cells demonstrated fibroblast like morphology with population doubling times of approximately 24 ± 0.5 h. Karyotyping analysis showed a distribution of 2n = 40 chromosome number for this cell line. The comparison of different incubation media and temperatures showed that cell growth is equally optimal in all mentioned conditions according to growth curves. Adipose and osteoblast differentiation was obviously observed in these cells which confirms the hint of stem-ness in the produced mixed cells. According to cell banking policies, produced cells were also checked for bacterial, fungal, yeast and mycoplasma contaminations and no contamination was observed. Multiplex PCR for identification of species confirmed the species of lizard with no cross-contamination with other cells in the cell bank. Establishment of authenticated and well-characterized lizard's original tail cell line will provide a valuable source for subsequent in vitro regenerative research and molecular studies which are not feasible in in vivo methods. This finding will allow us to get an opportunity to create and preserve a new collection of lizard cell lines in the future.

Development of a continuous cell line from larval Atlantic cod (Gadus morhua) and its use in the study of the microsporidian, Loma morhua

In vitro cell culture methods are crucial for the isolation, purification and mass propagation of intracellular pathogens of aquatic organisms. Cell culture infection models can yield insights into infection mechanisms, aid in developing methods for disease mitigation and prevention, and inform commercial-scale cultivation approaches. This study details the establishment of a larval cell line (GML-5) from the Atlantic cod (Gadus morhua) and its use in the study of microsporidia. GML-5 has survived over 100 passages in 8 years of culture. The line remains active and viable between 8 and 21°C in Leibovitz-15 (L-15) media with 10% foetal bovine serum and exhibits a myofibroblast phenotype as indicated by immuno-positive results for vimentin, α-smooth muscle actin, collagen I and S-100 proteins, while being desmin-negative. GML-5 supports the infection and development of two microsporidian parasites, an opportunistic generalist (Anncaliia algerae) and cod-specific Loma morhua. Using GML-5, spore germination and proliferation of L. morhua was found to require exposure to basic pH and cool incubation temperatures (8°C), in contrast to A. algerae, which required no cultural modifications. Loma morhua-associated xenoma-like structures were observed 2 weeks postexposure. This in vitro infection model may serve as a valuable tool for cod parasitology and aquaculture research.

Anti-angiogenic efficacy of aflibercept and bevacizumab in primary oral squamous cell carcinoma cells

BACKGROUND

In recent decades, anti-angiogenic treatment strategy has been well described in cancer treatment. The anti-angiogenic activity of both bevacizumab and aflibercept has been researched on 10 previously established primary oral squamous cell carcinoma (OSCC) cells of an Iranian population with different levels of purity, in an attempt to find the most effective anti-angiogenic-targeted drug.

METHODS

To investigate and compare the effect of bevacizumab and aflibercept on vascular endothelial growth factor (VEGF) secretion of 10 primary OSCC cells, cell proliferation and viability were assessed by ELISA and MTT assays. In addition, cell migration was studied using scratch assay.

RESULTS

The results showed that VEGF impressively expressed in all primary cancer cells. Although both drugs significantly reduced the secretion of VEGF, the effect of aflibercept was more prominent. Also, bevacizumab-treated cells migration was lower than the control group and the cells treated with aflibercept showed the lowest migration rate compared to bevacizumab and control groups.

CONCLUSION

The anti-angiogenic-targeted drugs, especially Af, might be effective in treatment of patients with OSCC in combination with conventional surgical treatments.

Systematic Review: Characteristics and Preclinical Uses of Bladder Cancer Cell Lines

BACKGROUND

Bladder cancer (BC) cell lines are indispensable in basic and preclinical research. Currently, an up-to-date and comprehensive overview of available BC cell lines is not available.

OBJECTIVE

To provide an overview and resources on the origin, pathological and molecular characteristics of commonly used human, murine and canine BC cell lines.

METHODS

A PubMed search was performed for relevant articles published between 1980 and 2017 according to the following MeSH terms: cell line; cell line, tumor; urinary bladder neoplasms; carcinoma, transitional cell. The Cellosaurus database was searched, using the term "bladder" and/or "urothelial carcinoma". We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We provide information on 157 human, murine and canine BC cell lines. 103 human BC cell lines have molecular data available, of which 69 have been profiled by at least one "omic" technology. We outline how these cell lines are currently being used for in vitro and in vivo experimental models. These results allow direct comparison of BC cell lines to patient samples, providing information needed to make informed decisions on the most genomically appropriate cell line to answer research questions. Furthermore, we show that cross-contamination remains an issue and describe guidelines for prevention.

CONCLUSIONS

In the BC field, multiple human, murine and canine BC cell lines have been developed and many have become indispensable for in vitro and in vivo research. High-throughput -omic technologies have dramatically increased the amount of molecular data on these cell lines. We synthesized a comprehensive overview of these data as a resource for the BC scientific community.

Development of new preclinical models to advance adrenocortical carcinoma research

Adrenocortical cancer (ACC) is an orphan malignancy that results in heterogeneous clinical phenotypes and molecular genotypes. There are no curative treatments for this deadly cancer with 35% survival at five years. Our understanding of the underlying pathobiology and our ability to test novel therapeutic targets has been limited due to the lack of preclinical models. Here, we report the establishment of two new ACC cell lines and corresponding patient-derived xenograft (PDX) models. CU-ACC1 cell line and PDX were derived from a perinephric metastasis in a patient whose primary tumor secreted aldosterone. CU-ACC2 cell line and PDX were derived from a liver metastasis in a patient with Lynch syndrome. Short tandem repeat profiling confirmed consistent matches between human samples and models. Both exomic and RNA sequencing profiling were performed on the patient samples and the models, and hormonal secretion was evaluated in the new cell lines. RNA sequencing and immunohistochemistry confirmed the expression of adrenal cortex markers in the PDXs and human tumors. The new cell lines replicate two of the known genetic models of ACC. CU-ACC1 cells had a mutation in CTNNB1 and secreted cortisol but not aldosterone. CU-ACC2 cells had a TP53 mutation and loss of MSH2 consistent with the patient's known germline mutation causing Lynch syndrome. Both cell lines can be transfected and transduced with similar growth rates. These new preclinical models of ACC significantly advance the field by allowing investigation of underlying molecular mechanisms of ACC and the ability to test patient-specific therapeutic targets.

Bovine leukemia virus linked to breast cancer but not coinfection with human papillomavirus: Case-control study of women in Texas

BACKGROUND

Bovine leukemia virus (BLV) and human papillomavirus (HPV) were previously identified in human breast tissue and have been associated with breast cancer in independent studies. The objective of the current study was to test for the presence of BLV and HPV in the same breast tissue specimens to determine whether the viruses were associated with breast cancer either singly or together.

METHODS

Archival formalin-fixed paraffin-embedded breast tissue sections from 216 women were received from The University of Texas MD Anderson Cancer Center along with patient diagnosis. In situ polymerase chain reaction and/or DNA hybridization methods were used to detect targeted DNA segments of BLV and HPV. Standard statistical methods were used to calculate age-adjusted odds ratios, attributable risk, and P values for the trend related to the association between presence of a virus and a diagnosis of breast disease.

RESULTS

Women diagnosed with breast cancer were significantly more likely to have BLV DNA in their breast tissue compared with women with benign diagnoses and no history of breast cancer. Women with breast pathology classified as premalignant and no history of breast cancer also were found to have an elevated risk of harboring BLV DNA in their breast tissue. HPV status was not associated with malignancy, premalignant breast disease, or the presence of BLV in the breast tissues.

CONCLUSIONS

The data from the current study supported previous findings of a significant association between BLV DNA in breast tissue and a diagnosis of breast cancer, but did not demonstrate oncogenic strains of HPV associated with breast cancer or the presence of BLV DNA in breast tissue. The authors believe the findings of the current study contribute to overall knowledge regarding a possible causal role for viruses in human breast cancer. Cancer 2018;124:1342-9. © 2017 American Cancer Society.

Sequential actions of phosphatidylinositol phosphates regulate phagosome-lysosome fusion

Phagosome-with-lysosome fusion comprises subreactions with differential lipid requirements: PI(4)P is required during and after phagosome-to-lysosome tethering, and PI(3)P is required after tethering. Moreover, PI(4)P serves to anchor to (phago)lysosome membranes Arl8 and HOPS, whereas PI(3)P contributes to membrane binding of HOPS only.

Phagosomes mature into phagolysosomes by sequential fusion with early endosomes, late endosomes, and lysosomes. Phagosome-with-lysosome fusion (PLF) results in the delivery of lysosomal hydrolases into phagosomes and in digestion of the cargo. The machinery that drives PLF has been little investigated. Using a cell-free system, we recently identified the phosphoinositide lipids (PIPs) phosphatidylinositol 3-phosphate (PI(3)P) and phosphatidylinositol 4-phosphate (PI(4)P) as regulators of PLF. We now report the identification and the PIP requirements of four distinct subreactions of PLF. Our data show that (i) PI(3)P and PI(4)P are dispensable for the disassembly and activation of (phago)lysosomal soluble N-ethylmaleimide-sensitive factor attachment protein receptors, that (ii) PI(3)P is required only after the tethering step, and that (iii) PI(4)P is required during and after tethering. Moreover, our data indicate that PI(4)P is needed to anchor Arl8 (Arf-like GTPase 8) and its effector homotypic fusion/vacuole protein sorting complex (HOPS) to (phago)lysosome membranes, whereas PI(3)P is required for membrane association of HOPS only. Our study provides a first link between PIPs and established regulators of membrane fusion in late endocytic trafficking.

Optimization of cell lines as tumour models by integrating multi-omics data

Cell lines are widely used as in vitro models of tumorigenesis. However, an increasing number of researchers have found that cell lines differ from their sourced tumour samples after long-term cell culture. The application of unsuitable cell lines in experiments will affect the experimental accuracy and the treatment of patients. Therefore, it is imperative to identify optimal cell lines for each cancer type. Here, we review the methods used to evaluate cell lines since 2005. Furthermore, gene expression, copy number and mutation profiles from The Cancer Genome Atlas and the Cancer Cell Line Encyclopedia are used to calculate similarity between tumours and cell lines. Then, the ideal cell lines to use for experiments for eight types of cancers are found by combining the results with Gene Ontology functional similarity. After verification, the optimal cell lines have the same genomic characteristics as their homologous tumour samples. The contaminated cell lines identified in previous research are also determined to be unsuitable in vitro cancer models here. Moreover, our study suggests that some of the commonly used cell lines are not suitable cancer models. In summary, we provide a reference for ideal cell lines to use in in vitro experiments and contribute to improving the accuracy of future cancer research. Furthermore, this research provides a foundation for identifying more effective treatment strategies.