Comparative study of the effects of PEGylated interferon-α2a versus 5-fluorouracil on cancer stem cells in a rat model of hepatocellular carcinoma

Multi-Omics Identification of Genetic Alterations in Head and Neck Squamous Cell Carcinoma and Therapeutic Efficacy of HNC018 as a Novel Multi-Target Agent for c-MET/STAT3/AKT Signaling Axis

Amongst the most prevalent malignancies worldwide, head and neck squamous cell carcinoma (HNSCC) is characterized by high morbidity and mortality. The failure of standard treatment modalities, such as surgery, radiotherapy, and chemotherapy, demands the need for in-depth understanding of the complex signaling networks involved in the development of treatment resistance. A tumor's invasive growth and high levels of intrinsic or acquired treatment resistance are the primary causes of treatment failure. This may be a result of the presence of HNSCC's cancer stem cells, which are known to have self-renewing capabilities that result in therapeutic resistance. Using bioinformatics methods, we discovered that elevated expressions of MET, STAT3, and AKT were associated with poor overall survival in HNSCC patients. We then evaluated the therapeutic potential of our newly synthesized small molecule HNC018 towards its potential as a novel anticancer drug. Our computer-aided structure characterization and target identification study predicted that HNC018 could target these oncogenic markers implicated in HNSCC. Subsequently, the HNC018 has demonstrated its anti-proliferative and anticancer activities towards the head and neck squamous cell carcinoma cell lines, along with displaying the stronger binding affinities towards the MET, STAT3, and AKT than the standard drug cisplatin. Reduction in the clonogenic and tumor-sphere-forming ability displays HNC018's role in decreasing the tumorigenicity. Importantly, an vivo study has shown a significant delay in tumor growth in HNC018 alone or in combination with cisplatin-treated xenograft mice model. Collectively with our findings, HNC018 highlights the desirable properties of a drug-like candidate and could be considered as a novel small molecule for treating head and neck squamous cell carcinoma.

α-Hederin Saponin Augments the Chemopreventive Effect of Cisplatin against Ehrlich Tumors and Bioinformatic Approach Identifying the Role of SDF1/CXCR4/p-AKT-1/NFκB Signaling

Stromal cell-derived factor-1 (SDF1) and its C-X-C chemokine receptor type 4 receptor (CXCR4) are significant mediators for cancer cells’ proliferation, and we studied their expression in Ehrlich solid tumors (ESTs) grown in mice. α-Hederin is a pentacyclic triterpenoid saponin found in Hedera or Nigella species with biological activity that involves suppression of growth of breast cancer cell lines. The aim of this study was to explore the chemopreventive activity of α-hederin with/without cisplatin; this was achieved by measuring the reduction in tumor masses and the downregulation in SDF1/CXCR4/pAKT signaling proteins and nuclear factor kappa B (NFκB). Ehrlich carcinoma cells were injected in four groups of Swiss albino female mice (Group1: EST control group, Group2: EST + α-hederin group, Group3: EST + cisplatin group, and Group4: EST+α-hederin/cisplatin treated group). Tumors were dissected and weighed, one EST was processed for histopathological staining with hematoxylin and eosin (HE), and the second MC was frozen and processed for estimation of signaling proteins. Computational analysis for these target proteins interactions showed direct-ordered interactions. The dissected solid tumors revealed decreases in tumor masses (~21%) and diminished viable tumor regions with significant necrotic surrounds, particularly with the combination regimens. Immunohistochemistry showed reductions (~50%) in intratumoral NFκβ in the mouse group that received the combination therapy. The combination treatment lowered the SDF1/CXCR4/p-AKT proteins in ESTs compared to the control. In conclusion, α-hederin augmented the chemotherapeutic potential of cisplatin against ESTs; this effect was at least partly mediated through suppressing the chemokine SDF1/CXCR4/p-AKT/NFκB signaling. Further studies are recommended to verify the chemotherapeutic potential of α-hederin in other breast cancer models.

Ameliorative potential of manganese nanoparticles with low-level ionizing radiation against experimentally induced hepatocarcinogenesis

Nanotechnology is a rich field with infinite possibilities of drug designs for cancer treatment. We aimed to biosynthesize manganese nanoparticles (Mn NPs) using Lactobacillus helveticus to investigate its anticancer synergistic effect with low-dose gamma radiation on HCC-induced rats. Diethylnitrosamine (DEN) (20 mg/kg BW, 5 times a week for 6 weeks) induced HCC in rats. Rats received Mn NPs (5 mg/kg BW/day) by gastric gavage over 4 weeks concomitant with single dose of gamma radiation (γ-R) (0.25 Gy). Characterization, cytotoxicity, and anticancer activity of Mn NPs were evaluated. DEN-induced significant liver dysfunction (alanine transaminase activity ALT, total proteins, and albumin levels) associated with significant increase in lipid peroxidation levels with reduction in super oxide dismutase activity. Furthermore, DEN intoxication is sponsored for remarkable increase in levels of Alfa-fetoprotein, tumor necrosis factor α, vascular endothelial growth factor, and transforming growth factor beta with remarkable decrease in caspase 3 and cytochrome c. Treatment with Mn NPs (4.98-11.58 nm) and single dose gamma radiation evoked significant repair in ALT, total protein, and albumin accompanied with balanced oxidative status, diminished inflammatory biomarkers, angiogenic factor, and growth factor with restoration in apoptotic factors. Mn NPs revealed obvious in vitro cytotoxic activity against HepG2 cell line in a dose-dependent manner. Our findings were well appreciated with the histopathological study. In conclusion, a new approach of the single or combined use of Mn NPs with low-dose γ-radiation regimens as promising paradigm for HCC treatment is recommended.

GNS561, a New Autophagy Inhibitor Active against Cancer Stem Cells in Hepatocellular Carcinoma and Hepatic Metastasis from Colorectal Cancer

Patients with advanced hepatocellular carcinoma (HCC) or metastatic colorectal cancer (mCRC) have a very poor prognosis due to the lack of efficient treatments. As observed in several other tumors, the effectiveness of treatments is mainly hampered by the presence of a highly tumorigenic sub-population of cancer cells called cancer stem cells (CSCs). Indeed, CSCs are resistant to chemotherapy and radiotherapy and can regenerate the tumor bulk. Hence, innovative drugs that are efficient against both bulk tumor cells and CSCs would likely improve cancer treatment. In this study, we demonstrated that GNS561, a new autophagy inhibitor that induces lysosomal cell death, showed significant activity against not only the whole tumor population but also a sub-population displaying CSC features (high ALDH activity and tumorsphere formation ability) in HCC and in liver mCRC cell lines. These results were confirmed in vivo in HCC from a DEN-induced cirrhotic rat model in which GNS561 decreased tumor growth and reduced the frequency of CSCs (CD90+CD45-). Thus, GNS561 offers great promise for cancer therapy by exterminating both the tumor bulk and the CSC sub-population. Accordingly, a global phase 1b clinical trial in liver cancers was recently completed.

Vitamin D potentiates anti-tumor activity of 5-fluorouracil via modulating caspase-3 and TGF-β1 expression in hepatocellular carcinoma-induced in rats

We investigated the role of vitamin D (Vit D) alone and in combination with 5-fluorouracil (5-FU) in thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. Fifty male Sprague-Dawley rats were randomized into a control group and 4 groups that received TAA (200 mg/kg, i.p.) twice per week for 16 weeks. These 4 groups were further divided as follows: HCC group; 5-FU group (75 mg/kg, i.p., once weekly for 3 weeks starting from the 12th week); Vit D group (200 IU/kg daily by oral tube for 16 weeks); and 5-FU + Vit D group (received the previously mentioned dosage regimens of 5-FU and Vit D). HCC was detected by histopathological changes in liver sections and the elevation of serum α-fetoprotein (AFP). Treatment with 5-FU + Vit D significantly decreased gene expression of nuclear factor erythroid 2-related factor 2 (NrF2) and transforming growth factor β1 (TGF-β1) at both the gene and protein level and serum AFP concentrations in comparison with their corresponding monotherapy. Moreover, 5-FU + Vit D treatment enhanced apoptosis by increasing caspase-3 gene and protein expression. Conclusively, Vit D enhances antitumor activity of 5-FU in an HCC-induced model and improves liver function of treated animals. Combination therapy in a TAA-induced HCC rat model was more effective than 5-FU or Vit D through the modulation of TGF-β1, caspase-3, and NrF2 expressions.

Combined treatment with sorafenib and silibinin synergistically targets both HCC cells and cancer stem cells by enhanced inhibition of the phosphorylation of STAT3/ERK/AKT

Silibinin, a nontoxic bioactive component in milk thistle, is used as a liver-protective drug in the clinic mainly because of its antioxidant and anti-inflammation activities. In this study, we studied the cytotoxic effects of silibinin combined with sorafenib on hepatocellular carcinoma (HCC). The results indicated that silibinin combined with sorafenib potently inhibited the proliferation of various HCC cells and induced significant apoptosis. In an HCC subcutaneous transplantation tumor model, the combination of silibinin and sorafenib significantly suppressed tumor growth compared with monotherapy. As determined by fluorescence staining and Western blots, the combination of the two drugs inhibited the phosphorylation of RAC-alpha serine/threonine-protein kinase (AKT) and signal transducer and activator of transcription 3 (STAT3) together with the expression of antiapoptotic proteins including myeloid leukemia cell differentiation protein Mcl-1 (Mcl-1) and apoptosis regulator Bcl-2 (Bcl-2), resulting in the death of cancer cells. We also found that the combination inhibited the formation and self-renewal of HCC stem cells by down-regulating the expression of stemness-related proteins, such as Homeobox protein NANOG (Nanog) and Krueppel-like factor 4 (Klf4). These results suggested that silibinin improved the efficacy of sorafenib in HCC therapy, indicating a clinical promising therapeutic strategy for HCC patients.

The added value of type I interferons to cytotoxic treatments of cancer

Type I interferons (IFNs) exert anti-proliferative, antiviral and immunomodulatory activities. They are also involved in cell differentiation and anti-tumor defense processes. A growing body of literature indicates that the success of conventional chemotherapeutics, epigenetic drugs, targeted anticancer agents and radiotherapy (RT) relies, at least in part, on the induction of type I IFN signaling in malignant cells, tumor-infiltrating antigen presenting cells or other immune cells within lymphoid organs or blood. The mechanisms underlying type I IFN induction and the clinical consequences of these observations are only beginning to be elucidated. In the present manuscript, we reviewed the recent advances in the field and provided our personal view on the role of type I IFNs induced in the context of cytotoxic anticancer treatments and on its possible exploitation as a complement in cancer therapy.

Screening of breast cancer stem cell inhibitors using a protein kinase inhibitor library

BACKGROUND

Cancer stem cells (CSCs), a subpopulation in tumors, are known to cause drug resistance, tumor recurrence and metastasis. Based on the characteristic formation of mammospheres in in vitro conditions, the mammosphere formation assay has become an essential tool for quantifying CSC activity in breast cancer research. However, manual counting of mammospheres is a time-consuming process that is not amenable to high-throughput screening, and there are occasional inaccuracies in the process of determining the mammosphere diameter. In this study, we proposed a novel automated counting method of mammosphere using the National Institute of Standards and Technology (NIST)'s Integrated Colony Enumerator (NICE) with a screening of protein kinase library.

METHODS

Human breast cancer cell line MCF-7 was used for evaluation of tumor sphere efficiency, migration, and phenotype transition. Cell viability was assessed using MTT assay, and CSCs were identified by an analysis of CD44 expression and ALDEFLUOR assay using flow cytometry. Automated counting of mammosphere using NICE program was performed with a comparison to the result of manual counting. After identification of inhibitors to ameliorate CSC formation by screening a library of 79 protein kinase inhibitors using automated counting in primary, secondary and tertiary mammosphere assay, the effect of selected kinase inhibitors on migration, colony formation and epithelial-to-mesenchymal transition (EMT) of MCF-7 cells was investigated.

RESULTS

Automated counting of mammosphere using NICE program was an easy and less time-consuming process (<1 min for reading 6-well plate) which provided a comparable result with manual counting. Inhibition of calcium/calmodulin-dependent protein kinase II (CaMKII), Janus kinase-3 (JAK-3), and IκB kinase (IKK) were identified to decrease the formation of MCF-7-derived CSCs in primary, secondary and tertiary mammosphere assay. These protein kinase inhibitors alleviated TGF-β1-induced migration, colony formation and EMT of MCF-7 cells.

CONCLUSIONS

We have developed a novel automated cell-based screening method which provided an easy, accurate and reproducible way for mammosphere quantification. This study is the first to show the efficacy of an automated medium-throughput mammosphere-counting method in CSC-related research with an identification of protein kinase inhibitors to ameliorate CSC formation.

Long Noncoding RNA lncCAMTA1 Promotes Proliferation and Cancer Stem Cell-Like Properties of Liver Cancer by Inhibiting CAMTA1

Hepatocellular carcinoma (HCC) is the most common subtype of liver malignancy, and it is characterized by poor prognosis because of cancer stem cell (CSC)-mediated high postsurgical recurrence rates. Thus, targeting CSCs, or HCC cells with CSC-like properties, is an effective strategy for HCC therapy. Here, using long noncoding RNA (lncRNA) microarray analysis, we identified a novel lncRNA termed lncCAMTA1 that is increased in both liver CSCs and HCC. High lncCAMTA1 expression in HCC indicates poor clinical outcome. In vitro and in vivo functional experiments showed that overexpression of lncCAMTA1 promotes HCC cell proliferation, CSC-like properties, and tumorigenesis. Conversely, depletion of lncCAMTA1 inhibits HCC cell proliferation, CSC-like properties, and tumorigenesis. Mechanistically, we demonstrated that lncCAMTA1 physically associates with the calmodulin binding transcription activator 1 (CAMTA1) promoter, induces a repressive chromatin structure, and inhibits CAMTA1 transcription. Furthermore, CAMTA1 is required for the effects of lncCAMTA1 on HCC cell proliferation and CSC-like properties, and the expression of lncCAMTA1 and CAMTA1 is significantly negatively correlated in HCC tissues. Collectively, our study revealed the important roles and underlying molecular mechanisms of lncCAMTA1 on HCC, and suggested that lncCAMTA1 could be an effective prognostic factor and a potential therapeutic target for HCC.

Multiple regulation pathways and pivotal biological functions of STAT3 in cancer

STAT3 is both a transcription activator and an oncogene that is tightly regulated under normal physiological conditions. However, abundant evidence indicates that STAT3 is persistently activated in several cancers, with a crucial position in tumor onset and progression. In addition to its traditional role in cancer cell proliferation, invasion, and migration, STAT3 also promotes cancer through altering gene expression via epigenetic modification, inducing epithelial–mesenchymal transition (EMT) phenotypes in cancer cells, regulating the tumor microenvironment, and promoting cancer stem cells (CSCs) self-renewal and differentiation. STAT3 is regulated not only by the canonical cytokines and growth factors, but also by the G-protein-coupled receptors, cadherin engagement, Toll-like receptors (TLRs), and microRNA (miRNA). Despite the presence of diverse regulators and pivotal biological functions in cancer, no effective therapeutic inventions are available for inhibiting STAT3 and acquiring potent antitumor effects in the clinic. An improved understanding of the complex roles of STAT3 in cancer is required to achieve optimal therapeutic effects.