Ovarian cancer is the most lethal gynecologic malignancy with an overall cure rate of merely 30%. Most patients experience recurrence within 12-24 months of cure and die of progressively chemotherapy-resistant disease. Thus, more effective anti-ovarian cancer therapies are needed. Here, we investigate the possibility of repurposing antibiotic monensin as an anti-ovarian cancer agent. We demonstrate that monensin effectively inhibits cell proliferation, migration and cell cycle progression, and induces apoptosis of human ovarian cancer cells. Monensin suppresses multiple cancer-related pathways including Elk1/SRF, AP1, NFκB and STAT, and reduces EGFR expression in ovarian cancer cells. Monensin acts synergistically with EGFR inhibitors and oxaliplatin to inhibit cell proliferation and induce apoptosis of ovarian cancer cells. Xenograft studies confirm that monensin effectively inhibits tumor growth by suppressing cell proliferation through targeting EGFR signaling. Our results suggest monensin may be repurposed as an anti-ovarian cancer agent although further preclinical and clinical studies are needed.

The prominent role of Fanconi anemia (FA) proteins involves homologous recombination (HR) repair. Poly[ADP-ribose] polymerase1 (PARP1) functions in multiple cellular processes including DNA repair and PARP inhibition is an emerging targeted therapy for cancer patients deficient in HR. Here we show that PARP1 activation in hematopoietic stem and progenitor cells (HSPCs) in response to genotoxic or oxidative stress attenuates HSPC exhaustion. Mechanistically, PARP1 controls the balance between HR and non-homologous end joining (NHEJ) in double strand break (DSB) repair by preventing excessive NHEJ. Disruption of the FA core complex skews PARP1 function in DSB repair and led to hyper-active NHEJ in Fanca(-/-) or Fancc(-/-) HSPCs. Re-expression of PARP1 rescues the hyper-active NHEJ phenotype in Brca1(-/-)Parp1(-/-) but less effective in Fanca(-/-)Parp1(-/-) cells. Inhibition of NHEJ prevents myeloid/erythroid pathologies associated with synthetic lethality. Our results suggest that hyper-active NHEJ may select for "synthetic lethality" resistant and pathological HSPCs.

Measuring conditional relatedness between a pair of genes is a fundamental technique and still a significant challenge in computational biology. Such relatedness can be assessed by gene expression similarities while suffering high false discovery rates. Meanwhile, other types of features, e.g., prior-knowledge based similarities, is only viable for measuring global relatedness. In this paper, we propose a novel machine learning model, named Multi-Features Relatedness (MFR), for accurately measuring conditional relatedness between a pair of genes by incorporating expression similarities with prior-knowledge based similarities in an assessment criterion. MFR is used to predict gene-gene interactions extracted from the COXPRESdb, KEGG, HPRD, and TRRUST databases by the 10-fold cross validation and test verification, and to identify gene-gene interactions collected from the GeneFriends and DIP databases for further verification. The results show that MFR achieves the highest area under curve (AUC) values for identifying gene-gene interactions in the development, test, and DIP datasets. Specifically, it obtains an improvement of 1.1% on average of precision for detecting gene pairs with both high expression similarities and high prior-knowledge based similarities in all datasets, comparing to other linear models and coexpression analysis methods. Regarding cancer gene networks construction and gene function prediction, MFR also obtains the results with more biological significances and higher average prediction accuracy, than other compared models and methods. A website of the MFR model and relevant datasets can be accessed from http://bmbl.sdstate.edu/MFR .

Cones are responsible for daylight, central, high acuity and color vision. Three proteins found in human cones, i.e. long-wavelength (L)-, middle-wavelength (M)-, and short-wavelength sensitive (S)-opsins, are responsible for red, green and blue color recognition, respectively. Human blue cone monochromacy (BCM) is characterized by functional loss of both L- and M-cone opsins due to mutations in the OPN1LW/OPN1MW gene cluster on the X chromosome. BCM patients, who rely on their vision from only S-cones and rods, suffer severely reduced visual acuity and impaired color vision. Recent studies show that there is sufficient cone structure remaining in the central fovea of BCM patients to consider AAV-mediated gene augmentation therapy. In contrast, mouse retina has only two opsins, S-opsin and M-opsin, but no L-opsin. We generated an M-opsin knockout mouse (Opn1mw -/-) expressing only S-opsin as a model for human BCM. We show that recombinant M-opsin delivered by AAV5 vectors rescues M-cone function in Opn1mw -/- mice. We also show that AAV delivered M-opsin localizes in the dorsal cone outer segments, and co-localizes with S-opsin in the ventral retina. Our study demonstrates that cones without M-opsin remain viable and respond to gene augmentation therapy, thereby providing proof-of-concept for cone function restoration in BCM patients.

Myeloid-derived suppressor cells (MDSCs) are known to play important roles in the development of immunosuppressive tumor microenvironment. A20 is a zinc-finger protein which could negatively regulate apoptosis in several cell types. However, the role of A20 in tumor microenvironment remains largely unknown. In this study, we found that A20 was over-expressed in MDSCs. The treatment of tumor-bearing mice with small interfering RNA targeting A20 (si-A20) inhibited the growth of tumors. The infiltration of MDSCs was dramatically reduced after si-A20 treatment, as compared to control groups, whereas the numbers of dendritic cells and macrophages were not affected. Also, injection of si-A20 improved T cell mediated tumor-specific immune response. Depletion of MDSCs with anti-Gr1 antibody showed similar antitumor effect and improved T cell response. TNF-α was highly expressed after si-A20 injection. Furthermore, si-A20 induced apoptosis of MDSCs in the presence of TNF-α both in vivo and in vitro. Cleaved Caspase-3 and Caspase-8 were elevated with the activation of JNK pathway after the induction of MDSC apoptosis by si-A20. Thus, our findings suggested that knockdown of A20 in tumor site inhibited tumor growth at least through inducing the apoptosis of MDSCs. A20 might be a potential target in anticancer therapy.

Fancd2 is a component of the Fanconi anemia (FA) DNA repair pathway, which is frequently found defective in human cancers. The full repertoire of Fancd2 functions in normal development and tumorigenesis remains to be determined. Here we developed a Flag- and hemagglutinin-tagged Fancd2 knock-in mouse strain that allowed a high throughput mass spectrometry approach to search for Fancd2-binding proteins in different mouse organs. In addition to DNA repair partners, we observed that many Fancd2-interacting proteins are mitochondrion-specific. Fancd2 localizes in the mitochondrion and associates with the nucleoid complex components Atad3 and Tufm. The Atad3-Tufm complex is disrupted in Fancd2-/- mice and those deficient for the FA core component Fanca. Fancd2 mitochondrial localization requires Atad3. Collectively, these findings provide evidence for Fancd2 as a crucial regulator of mitochondrion biosynthesis, and of a molecular link between FA and mitochondrial homeostasis.

Effective treatment of osteomyelitis remains a formidable clinical challenge. The rapid emergence of multidrug-resistant bacteria has renewed interest in developing antimicrobial biomaterials using antiseptic silver ions to treat osteomyelitis. However, inadequate local retention and severe cytotoxic effects have limited the clinical use of ionic silver for bone grafts. We recently developed novel porous nano-hydroxyapatite/polyamide 66 (nHP66)-based nanoscaffold materials containing varied concentrations of silver ions (Ag+) (TA-nHAPA66) and oxidized titanium (TiO2), which was added as a second binary element to enhance antibacterial activity and biocompatibility. In this study, we establish a large cohort of rabbit model of experimental osteomyelitis and investigate the in vivo antimicrobial and therapeutic effects of TA-nHP66 biomaterials and their in vivo silver release kinetics. We find the TA-nHP66 scaffolds exhibit potent antibacterial activities against E. coli and S. aureus, support cell adhesion and cell proliferation of pre-osteoblasts, and stimulate osteogenic regulator/marker expression. Moreover, the TA2-nHP66 scaffold exerts potent antibacterial/anti-inflammation effects in vivo and promotes bone formation at the lesion site of osteomyelitis. We further demonstrate that TA2-nHP66 exhibits excellent biosafety profile without apparent systemic toxicities. Therefore, the TA-nHP66 scaffold biomaterials may be further explored as an effective adjuvant therapy for infected bone defects and/or osteomyelitis debridement.

Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, variable congenital malformations and a predisposition to malignancies. FANCB (also known as FAAP95), is the only X-linked FA gene discovered thus far. In the present study, we investigated hematopoiesis in adult Fancb deficient (Fancb(-/y)) mice and found that Fancb(-/y) mice have decreased hematopoietic stem cell (HSC) quiescence accompanied by reduced progenitor activity in vitro and reduced repopulating capacity in vivo. Like other FA mouse models previously reported, the hematopoietic system of Fancb(-/y) mice is hypersensitive to DNA cross-linking agent mitomycin C (MMC), which induces bone marrow failure in Fancb(-/y) mice. Furthermore, Fancb(-/y) BM exhibits slower recovery kinetics and less tolerance to myelotoxic stress induced by 5-fluorouracil than wild-type littermates. RNA-seq analysis reveals altered expression of genes involved in HSC function and cell cycle regulation in Fancb(-/y) HSC and progenitor cells. Thus, this Fancb(-/y) mouse model provides a novel approach for studying the critical role of the FA pathway not only in germ cell development but also in the maintenance of HSC function.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly malignancies with <5% five-year survival rate due to late diagnosis, limited treatment options and chemoresistance. There is thus an urgent unmet clinical need to develop effective anticancer drugs to treat pancreatic cancer. Here, we study the potential of repurposing monensin as an anticancer drug for chemo-resistant pancreatic cancer. Using the two commonly-used chemo-resistant pancreatic cancer cell lines PANC-1 and MiaPaCa-2, we show that monensin suppresses cell proliferation and migration, and cell cycle progression, while solicits apoptosis in pancreatic cancer lines at a low micromole range. Moreover, monensin functions synergistically with gemcitabine or EGFR inhibitor erlotinib in suppressing cell growth and inducing cell death of pancreatic cancer cells. Mechanistically, monensin suppresses numerous cancer-associated pathways, such as E2F/DP1, STAT1/2, NFkB, AP-1, Elk-1/SRF, and represses EGFR expression in pancreatic cancer lines. Furthermore, the in vivo study shows that monensin blunts PDAC xenograft tumor growth by suppressing cell proliferation via targeting EGFR pathway. Therefore, our findings demonstrate that monensin can be repurposed as an effective anti-pancreatic cancer drug even though more investigations are needed to validate its safety and anticancer efficacy in pre-clinical and clinical models.

Proliferation and spatial development of colonic epithelial cells are highly regulated along the crypt vertical axis, which, when perturbed, can result in aberrant growth and carcinogenesis. In this study, two key factors were identified that have important and counterbalancing roles regulating these processes: pericrypt myofibroblast-derived Wnt-5a and the microbial metabolite butyrate. Cultured YAMC cell proliferation and heat shock protein induction were analzyed after butryate, conditioned medium with Wnt5a activity, and FrzB containing conditioned medium. In vivo studies to modulate Hsp25 employed intra-colonic wall Hsp25 encoding lentivirus. To silence Wnt-5a in vivo, intra-colonic wall Wnt-5a silencing RNA was used. Wnt-5a, secreted by stromal myofibroblasts of the lower crypt, promotes proliferation through canonical β-catenin activation. Essential to this are two key requirements: (1) proteolytic conversion of the highly insoluble ~40 kD Wnt-5a protein to a soluble 36 mer amino acid peptide that activates epithelial β-catenin and cellular proliferation, and (2) the simultaneous inhibition of butyrate-induced Hsp25 by Wnt-5a which is necessary to arrest the proliferative process in the upper colonic crypt. The interplay and spatial gradients of these factors insures that crypt epithelial cell proliferation and development proceed in an orderly fashion, but with sufficient plasticity to adapt to physiological perturbations including inflammation.

Chronic kidney disease (CKD) poses a formidable challenge for public healthcare worldwide as vast majority of patients with CKD are also at risk of accelerated cardiovascular disease and death. Renal fibrosis is the common manifestation of CKD that usually leads to end-stage renal disease although the molecular events leading to chronic renal fibrosis and eventually chronic renal failure remain to be fully understood. Nonetheless, emerging evidence suggests that an aberrant activation of PI3Kγ signaling may play an important role in regulating profibrotic phenotypes. Here, we investigate whether a blockade of PI3Kγ signaling exerts any beneficial effect on alleviating kidney injury and renal fibrosis. Using a mouse model of angiotensin II (Ang II)-induced renal damage, we demonstrate that PI3Kγ inhibitor AS605240 effectively mitigates Ang II-induced increases in serum creatinine and blood urea nitrogen, renal interstitial collagen deposition, the accumulation of ECM proteins and the expression of α-Sma and fibrosis-related genes in vivo. Mechanistically, we reveal that AS605240 effectively inhibits Ang II-induced cell proliferation and phosphorylation of Akt in fibroblast cells. Furthermore, we demonstrate that Ang II-upregulated expression of IL-6, Tnf-α, IL-1β and Tgf-β1 is significantly attenuated in the mice treated with AS605240. Taken together, our results demonstrate that PI3Kγ may function as a critical mediator of Ang II-induced renal injury and fibrosis. It is thus conceivable that targeted inhibition of PI3Kγ signaling may constitute a novel therapeutic approach to the clinical management of renal fibrosis, renal hypertension and/or CKD.