Interferon-β lipofection I. Increased efficacy of chemotherapeutic drugs on human tumor cells derived monolayers and spheroids

Celecoxib and sulindac sulfide elicit anticancer effects on PIK3CA-mutated head and neck cancer cells through endoplasmic reticulum stress, reactive oxygen species, and mitochondrial dysfunction

Gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit alpha gene (PIK3CA) is a significant factor in head and neck cancer (HNC). Patients with HNC harboring PIK3CA mutations receive therapeutic benefits from the use of non-steroidal anti-inflammatory drugs (NSAIDs). However, the molecular mechanisms underlying these effects remain unknown. Here, we examined the Detroit562 and FaDu cell lines as HNC models with and without a hyperactive PIK3CA mutation (H1047R), respectively, regarding their possible distinct responses to the NSAIDs celecoxib and sulindac sulfide (SUS). Detroit562 cells exhibited relatively high PI3K/Akt pathway-dependent cyclooxygenase-2 (COX-2) expression, associated with cell proliferation. Celecoxib treatment restricted cell proliferation and upregulated endoplasmic reticulum (ER) stress-related markers, including GRP78, C/EBP-homologous protein, activating transcription factor 4, death receptor 5, and reactive oxygen species (ROS). These effects were much stronger in Detroit562 cells than in FaDu cells and were largely COX-2-independent. SUS treatment yielded similar results. Salubrinal (an ER stress inhibitor) and N-acetyl-L-cysteine (a ROS scavenger) prevented NSAID-induced ROS generation and ER stress, respectively, indicating crosstalk between ER and oxidative stress. In addition, celecoxib and/or SUS elevated cleaved caspase-3 levels, Bcl-2-associated X protein/Bcl-2-interacting mediator of cell death expression, and mitochondrial damage, which was more pronounced in Detroit562 than in FaDu cells. Salubrinal and N-acetyl-L-cysteine attenuated celecoxib-induced mitochondrial dysfunction. Collectively, our results suggest that celecoxib and SUS efficiently suppress activating PIK3CA mutation-harboring HNC progression by inducing ER and oxidative stress and mitochondrial dysfunction, leading to apoptotic cell death, further supporting NSAID treatment as a useful strategy for oncogenic PIK3CA-mutated HNC therapy.

Modeling the Tumor Microenvironment and Pathogenic Signaling in Bone Sarcoma

Investigations of cancer biology and screening of potential therapeutics for efficacy and safety begin in the preclinical laboratory setting. A staple of most basic research in cancer involves the use of tissue culture plates, on which immortalized cell lines are grown in monolayers. However, this practice has been in use for over six decades and does not account for vital elements of the tumor microenvironment that are thought to aid in initiation, propagation, and ultimately, metastasis of cancer. Furthermore, information gleaned from these techniques does not always translate to animal models or, more crucially, clinical trials in cancer patients. Osteosarcoma (OS) and Ewing sarcoma (ES) are the most common primary tumors of bone, but outcomes for patients with metastatic or recurrent disease have stagnated in recent decades. The unique elements of the bone tumor microenvironment have been shown to play critical roles in the pathogenesis of these tumors and thus should be incorporated in the preclinical models of these diseases. In recent years, the field of tissue engineering has leveraged techniques used in designing scaffolds for regenerative medicine to engineer preclinical tumor models that incorporate spatiotemporal control of physical and biological elements. We herein review the clinical aspects of OS and ES, critical elements present in the sarcoma microenvironment, and engineering approaches to model the bone tumor microenvironment. Impact statement The current paradigm of cancer biology investigation and therapeutic testing relies heavily on monolayer, monoculture methods developed over half a century ago. However, these methods often lack essential hallmarks of the cancer microenvironment that contribute to tumor pathogenesis. Tissue engineers incorporate scaffolds, mechanical forces, cells, and bioactive signals into biological environments to drive cell phenotype. Investigators of bone sarcomas, aggressive tumors that often rob patients of decades of life, have begun to use tissue engineering techniques to devise in vitro models for these diseases. Their efforts highlight how critical elements of the cancer microenvironment directly affect tumor signaling and pathogenesis.

Combination of cytokine-enhanced vaccine and chemo-gene therapy as surgery adjuvant treatments for spontaneous canine melanoma

After 6 years of follow-up treating 364 canine melanoma patients, we present here results about the proof-of-concept, safety, and efficacy of a new surgery adjuvant combined gene therapy. The adjuvant treatment (AT) group was divided in three arms as follows: (i) complete surgery plus vaccine (CS-V), (ii) complete surgery plus combined treatment (CS-CT), and (iii) partial surgery plus combined treatment (PS-CT). Besides the genetic vaccines composed by tumor extracts and lipoplexes carrying human interleukin-2 and granulocyte-macrophage colony-stimulating factor genes, the patients were subjected to combined treatment received in the post-surgical bed injections of lipid-complexed thymidine kinase suicide gene plus ganciclovir and canine interferon-β gene plus bleomycin. As compared with surgery-only treated controls (So), CS-CT and CS-V treatments significantly increased the fraction of local disease-free (from 20 to 89 and 74%) and distant metastases-free patients (M0: from 45 to 87 and 84%). Although less effective than CS arms, PS-CT arm demonstrated a significantly improved control of metastatic disease (M0: 80%) compared with So (M0: 44%). In addition, AT produced a significant 9.3- (CS-CT), 6.5- (CS-V), and 5.4-fold (PS-CT) increase of overall survival as compared with their respective So controls. In general terms, the AT changed a lethal disease into a chronic disease where 70% of CS-CT, 51% of CS-V, and 14% of PS-CT patients died of melanoma unrelated causes. These surgery adjuvant treatments delayed or prevented post-surgical recurrence and distant metastasis, and improved disease-free and overall survival while maintaining quality of life. These successful outcomes encourage assaying a similar scheme for human melanoma.

Tissue engineered models of healthy and malignant human bone marrow

Tissue engineering is becoming increasingly successful in providing in vitro models of human tissues that can be used for ex vivo recapitulation of functional tissues as well as predictive testing of drug efficacy and safety. From simple tissue models to microphysiological platforms comprising multiple tissue types connected by vascular perfusion, these "tissues on a chip" are emerging as a fast track application for tissue engineering, with great potential for modeling diseases and supporting the development of new drugs and therapeutic targets. We focus here on tissue engineering of the hematopoietic stem and progenitor cell compartment and the malignancies that can develop in the human bone marrow. Our overall goal is to demonstrate the utility and interconnectedness of improvements in bioengineering methods developed in one area of bone marrow studies for the remaining, seemingly disparate, bone marrow fields.

Sarcoma Spheroids and Organoids-Promising Tools in the Era of Personalized Medicine

Cancer treatment is rapidly evolving toward personalized medicine, which takes into account the individual molecular and genetic variability of tumors. Sophisticated new in vitro disease models, such as three-dimensional cell cultures, may provide a tool for genetic, epigenetic, biomedical, and pharmacological research, and help determine the most promising individual treatment. Sarcomas, malignant neoplasms originating from mesenchymal cells, may have a multitude of genomic aberrations that give rise to more than 70 different histopathological subtypes. Their low incidence and high level of histopathological heterogeneity have greatly limited progress in their treatment, and trials of clinical sarcoma are less frequent than trials of other carcinomas. The main advantage of 3D cultures from tumor cells or biopsy is that they provide patient-specific models of solid tumors, and they overcome some limitations of traditional 2D monolayer cultures by reflecting cell heterogeneity, native histologic architectures, and cell-extracellular matrix interactions. Recent advances promise that these models can help bridge the gap between preclinical and clinical research by providing a relevant in vitro model of human cancer useful for drug testing and studying metastatic and dormancy mechanisms. However, additional improvements of 3D models are expected in the future, specifically the inclusion of tumor vasculature and the immune system, to enhance their full ability to capture the biological features of native tumors in high-throughput screening. Here, we summarize recent advances and future perspectives of spheroid and organoid in vitro models of rare sarcomas that can be used to investigate individual molecular biology and predict clinical responses. We also highlight how spheroid and organoid culture models could facilitate the personalization of sarcoma treatment, provide specific clinical scenarios, and discuss the relative strengths and limitations of these models.

Therapeutic potential of bleomycin plus suicide or interferon-β gene transfer combination for spontaneous feline and canine melanoma

We originated and characterized melanoma cell lines derived from tumors of two feline and two canine veterinary patients. These lines reestablished the morphology, physiology and cell heterogeneity of their respective parental tumors. We evaluated the cytotoxicity of bleomycin (BLM) alone, or combined with interferon-β (IFN-β) or HSVtk/GCV suicide gene (SG) lipofection on these cells. Although the four animals presented stage III disease (WHO system), SG treated feline tumors displayed stable disease in vivo, while the canine ones exhibited partial response. Their derived cell lines reflected this behavior. Feline were significantly more sensitive than canine cells to IFN-β gene transfer. BLM improved the antitumor effects of both genes. The higher levels of reactive oxygen species (ROS) significantly correlated with membrane and DNA damages, emphasizing ROS intervention in apoptotic and necrotic cell death. After 3 days of BLM alone or combined with gene treatments, the colony forming capacity of two canine and one feline treatments survivor cells almost disappeared. Taken together, these results suggest that the treatments eradicated tumor initiating cells and support the clinical potential of the tested combinations.

Immunomodulatory and antitumor effects of type I interferons and their application in cancer therapy

During the last decades, the pleiotropic antitumor functions exerted by type I interferons (IFNs) have become universally acknowledged, especially their role in mediating interactions between the tumor and the immune system. Indeed, type I IFNs are now appreciated as a critical component of dendritic cell (DC) driven T cell responses to cancer. Here we focus on IFN-α and IFN-β, and their antitumor effects, impact on immune responses and their use as therapeutic agents. IFN-α/β share many properties, including activation of the JAK-STAT signaling pathway and induction of a variety of cellular phenotypes. For example, type I IFNs drive not only the high maturation status of DCs, but also have a direct impact in cytotoxic T lymphocytes, NK cell activation, induction of tumor cell death and inhibition of angiogenesis. A variety of stimuli, including some standard cancer treatments, promote the expression of endogenous IFN-α/β, which then participates as a fundamental component of immunogenic cell death. Systemic treatment with recombinant protein has been used for the treatment of melanoma. The induction of endogenous IFN-α/β has been tested, including stimulation through pattern recognition receptors. Gene therapies involving IFN-α/β have also been described. Thus, harnessing type I IFNs as an effective tool for cancer therapy continues to be studied.

Cytokine-Enhanced Vaccine and Interferon-β plus Suicide Gene Therapy as Surgery Adjuvant Treatments for Spontaneous Canine Melanoma

We present here a nonviral immunogene therapy trial for canine malignant melanoma, an aggressive disease displaying significant clinical and histopathological overlapping with human melanoma. As a surgery adjuvant approach, it comprised the co-injection of lipoplexes bearing herpes simplex virus thymidine kinase and canine interferon-β genes at the time of surgery, combined with the periodic administration of a subcutaneous genetic vaccine composed of tumor extracts and lipoplexes carrying the genes of human interleukin-2 and human granulocyte-macrophage colony-stimulating factor. Following complete surgery (CS), the combined treatment (CT) significantly raised the portion of local disease-free canine patients from 11% to 83% and distant metastases-free (M0) from 44% to 89%, as compared with surgery-only-treated controls (ST). Even after partial surgery (PS), CT better controlled the systemic disease (M0: 82%) than ST (M0: 48%). Moreover, compared with ST, CT caused a significant 7-fold (CS) and 4-fold (PS) rise of overall survival, and >17-fold (CS) and >13-fold (PS) rise of metastasis-free survival. The dramatic increase of PS metastasis-free survival (>1321 days) and CS recurrence- and metastasis-free survival (both >2251 days) demonstrated that CT was shifting a rapidly lethal disease into a chronic one. In conclusion, this surgery adjuvant CT was able of significantly delaying or preventing postsurgical recurrence and distant metastasis, increasing disease-free and overall survival, and maintaining the quality of life. The high number of canine patients involved in CT (301) and the extensive follow-up (>6 years) with minimal or absent toxicity warrant the long-term safety and efficacy of this treatment. This successful clinical outcome justifies attempting a similar scheme for human melanoma.

3D tissue-engineered model of Ewing's sarcoma

Despite longstanding reliance upon monolayer culture for studying cancer cells, and numerous advantages from both a practical and experimental standpoint, a growing body of evidence suggests that more complex three-dimensional (3D) models are necessary to properly mimic many of the critical hallmarks associated with the oncogenesis, maintenance and spread of Ewing's sarcoma (ES), the second most common pediatric bone tumor. And as clinicians increasingly turn to biologically-targeted therapies that exert their effects not only on the tumor cells themselves, but also on the surrounding extracellular matrix, it is especially important that preclinical models evolve in parallel to reliably measure antineoplastic effects and possible mechanisms of de novo and acquired drug resistance. Herein, we highlight a number of innovative methods used to fabricate biomimetic ES tumors, encompassing both the surrounding cellular milieu and the extracellular matrix (ECM), and suggest potential applications to advance our understanding of ES biology, preclinical drug testing, and personalized medicine.

Cationic lipid:DNA complexes allow bleomycin uptake by melanoma cells

Bleomycin is a chemotherapeutic agent barely diffusible through the plasmatic membrane. We evaluated DNA/cationic lipids complexes (lipoplexes) as mediators of its uptake in four spontaneous canine melanoma derived cell lines (Ak, Bk, Br and Rkb). Cell survival after lipofection plus or minus bleomycin was determined by the acid phosphatase method and the cellular uptake of lipoplexes, carrying the E. coli β-galactosidase gene, was evidenced by SYBR Green I staining. The four cell lines resulted sensitive to the bleomycin/lipoplexes system in both spatial configurations. Survival rates values were lower than 20% in monolayers of the four tested lines and lower than 30% in three lines (Ak, Bk and Rkb) when grown as spheroids. The sensitization to bleomycin depended on lipoplexes in Ak and Rkb while Bk (in both spatial configurations) and Br (as monolayers) were sensitive to bleomycin alone. Although some degree of sensitivity to bleomycin was induced by cationic lipids alone in Ak and Rkb monolayers, the maximal bleomycin effects appeared in the presence of lipoplexes. The sensitization was independent of transcriptional activity. The co-administration of lipoplexes diminished bleomycin IC50: 10-fold in Ak and Rkb monolayers; and sensitized the Ak and Rkb resistant spheroids. The bleomycin cytotoxic effects depended on lipoplexes concentration and diminished when cells were incubated at 8°C. Our results suggest that lipoplexes sensitize cells to bleomycin, increasing its uptake by an active transport mechanism, such as endocytosis. The bleomycin/lipoplexes system appears as a promising combination of chemotherapy and non-viral cancer gene therapy.