Cholangiocarcinoma is a disease with a poor prognosis and increasing incidence and hence there is a pressing unmet clinical need for new adjuvant treatments. Protein kinase CK2 (previously casein kinase II) is a ubiquitously expressed protein kinase that is up-regulated in multiple cancer cell types. The inhibition of CK2 activity using CX-4945 (Silmitasertib) has been proposed as a novel treatment in multiple disease settings including cholangiocarcinoma. Here, we show that CX-4945 inhibited the proliferation of cholangiocarcinoma cell lines in vitro. Moreover, CX-4945 treatment induced the formation of cytosolic vacuoles in cholangiocarcinoma cell lines and other cancer cell lines. The vacuoles contained extracellular fluid and had neutral pH, features characteristic of methuosis. In contrast, simultaneous knockdown of both the α and α′ catalytic subunits of protein kinase CK2 using small interfering RNA (siRNA) had little or no effect on the proliferation of cholangiocarcinoma cell lines and failed to induce the vacuole formation. Surprisingly, low doses of CX-4945 increased the invasive properties of cholangiocarcinoma cells due to an upregulation of matrix metallopeptidase 7 (MMP-7), while the knockdown of CK2 inhibited cell invasion. Our data suggest that CX-4945 inhibits cell proliferation and induces cell death via CK2-independent pathways. Moreover, the increase in cell invasion brought about by CX-4945 treatment suggests that this drug might increase tumor invasion in clinical settings.

The association between iron overload and osteoporosis has been found in many diseases, such as hemochromatosis, β-thalassemia and sickle cell anemia with multiple blood transfusion. One of the contributing factors is iron toxicity to osteoblasts. Some studies showed the negative effects of iron on osteoblasts; however, the effects of two biological available iron species, i.e., ferric and ferrous, on osteoblasts are elusive. Since most intracellular ionized iron is ferric, osteoblasts was hypothesized to be more responsive to ferric iron. Herein, ferric ammonium citrate (FAC) and ferrous ammonium sulfate (FAS) were used as ferric and ferrous donors. Our results showed that both iron species suppressed cell survival and proliferation. Both also induced osteoblast cell death consistent with the higher levels of cleaved caspase 3 and caspase 7 in osteoblasts, indicating that iron induced osteoblast apoptosis. Iron treatments led to the elevated intracellular iron in osteoblasts as determined by atomic absorption spectrophotometry, thereby leading to a decreased expression of genes for cellular iron import and increased expression of genes for cellular iron export. Effects of FAC and FAS on osteoblast differentiation were determined by the activity of alkaline phosphatase (ALP). The lower ALP activity from osteoblast with iron exposure was found. In addition, ferric and ferrous differentially induced osteoblastic and osteoblast-derived osteoclastogenic gene expression alterations in osteoblast. Even though both iron species had similar effects on osteoblast cell survival and differentiation, the overall effects were markedly stronger in FAC-treated groups, suggesting that osteoblasts were more sensitive to ferric than ferrous.

Osteoporosis and derangement of calcium homeostasis are common complications of thalassemia. Despite being an important process for bone and calcium metabolism, little is known about intestinal calcium transport in thalassemia. Recent reports of decreases in both intestinal calcium transport and bone mineral density in thalassemic patients and animal models suggested that defective calcium absorption might be a cause of thalassemic bone disorder. Herein, the possible mechanisms associated with intestinal calcium malabsorption in thalassemia are discussed. This includes alterations in the calcium transporters and hormonal controls of the transcellular and paracellular intestinal transport systems in thalassemia. In addition, the effects of iron overload on intestinal calcium absorption, and the reciprocal interaction between iron and calcium transport in thalassemia are elaborated. Understanding the mechanisms underlining calcium malabsorption in thalassemia would lead to development of therapeutic agents and mineral supplements that restore calcium absorption as well as prevent osteoporosis in thalassemic patients.

One of the potential contributing factors for iron overload-induced osteoporosis is the iron toxicity on bone forming cells, osteoblasts. In this study, the comparative effects of Fe 3+ and Fe 2 + on osteoblast differentiation and mineralization were studied in UMR-106 osteoblast cells by using ferric ammonium citrate and ferrous ammonium sulfate as Fe 3+ and Fe 2+ donors, respectively. Effects of 1,25 dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ] and iron chelator deferiprone on iron uptake ability of osteoblasts were examined, and the potential protective ability of 1,25(OH) 2 D 3 , deferiprone and extracellular calcium treatment in osteoblast cell survival under iron overload was also elucidated. The differential effects of Fe 3+ and Fe 2+ on reactive oxygen species (ROS) production in osteoblasts were also compared. Our results showed that both iron species suppressed alkaline phosphatase gene expression and mineralization with the stronger effects from Fe 3+ than Fe 2+ . 1,25(OH) 2 D 3 significantly increased the intracellular iron but minimally affected osteoblast cell survival under iron overload. Deferiprone markedly decreased intracellular iron in osteoblasts, but it could not recover iron-induced osteoblast cell death. Interestingly, extracellular calcium was able to rescue osteoblasts from iron-induced osteoblast cell death. Additionally, both iron species could induce ROS production and G0/G1 cell cycle arrest in osteoblasts with the stronger effects from Fe 3+ . In conclusions, Fe 3+ and Fe 2+ differentially compromised the osteoblast functions and viability, which can be alleviated by an increase in extracellular ionized calcium, but not 1,25(OH) 2 D 3 or iron chelator deferiprone. This study has provided the invaluable information for therapeutic design targeting specific iron specie(s) in iron overload-induced osteoporosis. Moreover, an increase in extracellular calcium could be beneficial for this group of patients.

Background/Aim: Pyruvate carboxylase (PC) is a major anaplerotic enzyme for generating oxaloacetate for the TCA cycle and also a key enzyme in gluconeogenesis, de novo fatty acid and amino acid synthesis in normal cells. Recent studies have identified PC overexpression in different cancers, such as breast and lung. However, the involvement of PC in colorectal cancer (CRC) is unclear. Our purpose was to investigate the PC expression levels and its correlations with potentially relevant clinical-pathological parameters in CRC. Materials and Methods: PC expression levels in tissues from 60 Thai CRC patients were investigated by immunohistochemistry while a clonogenic assay was performed for determining cell growth of HT-29 cells with PC knockdown. Results: Our results showed for the first time that high PC expression levels were significantly correlated with late stage of the cancer, perineural invasion and lymph node metastasis. The overexpression of PC was also significantly associated with poor overall and disease-free survival times of CRC patients. In addition, suppression of cancer cell growth was found in PC-deficient cell lines using CRISPR-Cas9. Conclusion: The overexpression levels of PC were correlated with CRC progression and survival times. Therefore, PC might serve as a potential clinical prognostic marker for colorectal cancer.

Na/H exchanger (NHE)-3 is important for intestinal absorption of nutrients and minerals, including calcium. The previous investigations have shown that the intestinal calcium absorption is also dependent on luminal nutrients, but whether aliphatic amino acids and glucose, which are abundant in the luminal fluid during a meal, similarly enhance calcium transport remains elusive. Herein, we used the in vitro Ussing chamber technique to determine epithelial electrical parameters, i.e., potential difference (PD), short-circuit current (Isc), and transepithelial resistance, as well as Ca flux in the rat duodenum directly exposed on the mucosal side to glucose or various amino acids. We found that mucosal glucose exposure led to the enhanced calcium transport, PD, and Isc, all of which were insensitive to NHE3 inhibitor (100 nM tenapanor). In the absence of mucosal glucose, several amino acids (12 mM in the mucosal side), i.e., alanine, isoleucine, leucine, proline, and hydroxyproline, markedly increased the duodenal calcium transport. An inhibitor for NHE3 exposure on the mucosal side completely abolished proline- and leucine-enhanced calcium transport, but not transepithelial transport of both amino acids themselves. In conclusion, glucose and certain amino acids in the mucosal side were potent stimulators of the duodenal calcium absorption, but only amino-acid-enhanced calcium transport was NHE3-dependent.

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Extracellular nucleotides were first proposed as signaling molecules in 1972 (1). Signaling through purinergic receptors is ubiquitous due to the diversity of purine and pyrimidine ligands, the number of receptors and extracellular nucleotidases. Purinergic signaling has been shown to play a role in many pathways including neurotransmission (2), cell differentiation, hormone secretion, vasodilation, cell proliferation, wound healing and apoptosis (3). There are two distinct families of purinergic receptors: P1 receptors for adenosine and P2 receptors for ATP/ADP and UTP/UDP ligands. P2 receptors are further divided into ligand-gated ion channel receptors, P2X, and G protein-coupled receptor, P2Y, subfamilies. To date, four P1 receptors (A 1,2a,2b,3 ), seven P2X receptors (P2X 1-7 ) and eight P2Y receptors (P2Y 1,2,4,6,11-14 ) have been identified in mammalian cells (4). The adenosine receptor subtypes A 1 and A 3 downregulate the production of cAMP, while A 2a and A 2b subtypes up-regulate the production of cAMP. Activation of P2X receptors leads to an influx of cations from the extracellular space, while activation of P2Y receptors leads to either an elevation of intracellular Ca 2+ from endoplasmic reticulum stores or down-regulation of cAMP production depending on the specific subtype of P2Y receptor activated.Growth suppression by the P2 agonist, ATP, was demonstrated first by Rapaport in 1983 (5). Exogenous ATP was shown to suppress the growth of pancreatic and colon cancer by causing cell-cycle arrest in S-phase. To date, the anticancer activity of extracellular nucleotides has been investigated in many types of cancer, including leukemia, melanoma and non-melanoma skin cancer, colorectal cancer, lung cancer, cervical cancer, prostate cancer (PCa) and squamous cell skin cancer (6). These led to clinical trials in patients with colorectal and non-small cell lung cancer that showed promising results with limited side-effects (7-9).PCa is the most frequently diagnosed cancer in North American men and the second leading cause of cancerrelated death in American men. It was estimated that there would be approximately 180,890 new cases of PCa and 26,5120 related deaths in the United States alone in 2016 (10). Current standard treatments for advanced PCa include various hormonal therapies whose goal is the ablation of androgens and their action (11). Even though 70% to 80% of patients respond well to first-line treatment, most patients eventually develop castrate-resistant disease (CRPCa) (12). Novel therapy therefore is needed to eliminate both early and 529 Τhis article is freely accessible online.