pyrimidinones and Carcinogenesis

Survivin plays a key role in regulating the cell cycle and apoptosis, and is highly expressed in the majority of malignant tumors. However, little is known about the roles of survivin in KRAS-mutant lung adenocarcinomas. In the present study, we examined 28 KRAS-mutant lung adenocarcinoma tissues and two KRAS-mutant lung adenocarcinoma cell lines, H358 and H441, in order to elucidate the potential of survivin as a therapeutic target. We found that 19 (68%) of the 28 KRAS-mutant lung adenocarcinomas were differentiated tumors expressing thyroid transcription factor‑1 (TTF‑1) and E-cadherin. Patients with tumors immunohistochemically positive for survivin (n=18) had poorer outcomes than those with survivin-negative tumors (n=10). In the H358 and H441 cells, which expressed TTF‑1 and E-cadherin, survivin knockdown alone induced senescence, not apoptosis. However, in monolayer culture, the H358 cells and H441 cells in which survivin was silenced, underwent significant apoptosis following combined treatment with ABT-263, a Bcl‑2 inhibitor, and trametinib, a MEK inhibitor. Importantly, the triple combination of survivin knockdown with ABT-263 and trametinib treatment, clearly induced cell death in a three-dimensional cell culture model and in an in vivo tumor xenograft model. We also observed that the growth of the H358 and H441 cells was slightly, yet significantly suppressed in vitro when TTF‑1 was silenced. These findings collectively suggest that the triple combination of survivin knockdown with ABT-263 and trametinib treatment, may be a potential strategy for the treatment of KRAS-mutant lung adenocarcinoma. Furthermore, our findings indicate that the well‑differentiated type of KRAS-mutant lung tumors depends, at least in part, on TTF‑1 for growth.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Adult; Aged; Aged, 80 and over; Aniline Compounds; Cadherins; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Cellular Senescence; DNA-Binding Proteins; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Inhibitor of Apoptosis Proteins; Lung Neoplasms; Male; MAP Kinase Kinase Kinase 1; Middle Aged; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Sulfonamides; Survivin; Transcription Factors

It is generally known that glioblastoma is the most common primary malignant brain tumor and that it is highly aggressive and deadly. Although surgical and pharmacological therapies have made long‑term progress, glioblastoma remains extremely lethal and has an uncommonly low survival rate. Therefore, further elucidation of the molecular mechanisms of glioblastoma initiation and its pathological processes are urgent. Arsenic resistance protein 2 (Ars2) is a highly conserved gene, and it has been found to play an important role in microRNA biosynthesis and cell proliferation in recent years. Furthermore, absence of Ars2 results in developmental death in Drosophila, zebrafish and mice. However, there are few studies on the role of Ars2 in regulating tumor development, and the mechanism of its action is mostly unknown. In the present study, we revealed that Ars2 is involved in glioblastoma proliferation and we identified a potential mechanistic role for it in cell cycle control. Our data demonstrated that Ars2 knockdown significantly repressed the proliferation and tumorigenesis abilities of glioblastoma cells in vitro and in vivo. Further investigation clarified that Ars2 deficiency inhibited the activation of the MAPK/ERK pathway, leading to cell cycle arrest in the G1 phase, resulting in suppression of cell proliferation. These findings support the conclusion that Ars2 is a key regulator of glioblastoma progression.

Topics: Animals; Brain Neoplasms; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Disease Progression; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Glioblastoma; Humans; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Mice, SCID; Nuclear Proteins; Phosphorylation; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Xenograft Model Antitumor Assays

BRAF inhibitors are highly effective therapies for the treatment of BRAF(V600)-mutated melanoma, with the main toxicity being a variety of hyperproliferative skin conditions due to paradoxical activation of the mitogen-activated protein kinase (MAPK) pathway in BRAF wild-type cells. Most of these hyperproliferative skin changes improve when a MEK inhibitor is co-administered, as it blocks paradoxical MAPK activation. Here we show how the BRAF inhibitor vemurafenib accelerates skin wound healing by inducing the proliferation and migration of human keratinocytes through extracellular signal-regulated kinase (ERK) phosphorylation and cell cycle progression. Topical treatment with vemurafenib in two wound-healing mice models accelerates cutaneous wound healing through paradoxical MAPK activation; addition of a mitogen-activated protein kinase kinase (MEK) inhibitor reverses the benefit of vemurafenib-accelerated wound healing. The same dosing regimen of topical BRAF inhibitor does not increase the incidence of cutaneous squamous cell carcinomas in mice. Therefore, topical BRAF inhibitors may have clinical applications in accelerating the healing of skin wounds.

Topics: Administration, Topical; Animals; Carcinogenesis; Carcinogens; Carcinoma, Squamous Cell; Cell Cycle; Cell Line, Tumor; Female; Humans; Incidence; Indoles; Keratinocytes; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Neoplasms, Experimental; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Skin; Skin Neoplasms; Sulfonamides; Treatment Outcome; Vemurafenib; Wound Healing

The colon cancer tissues from DMH treated rats exhibited higher membrane potential, fluidity and changed lipid order as examined by Merocyanine 540 and 1,6-diphenyl-1,3,5-hexatriene, respectively. A transition from gel to liquid crystalline state was observed by Laurdan fluorescence and also reduced fluorescence quenching of NBD-PE as contributed in the decreased membrane lipid phase separation. With piroxicam, a traditional NSAID and c-phycocyanin, a biliprotein from Spirulina platensis, these effects were normalized. An augmented intracellular Ca(+2) had contributed to the drug mediated apoptosis which is supported by an elevated calpain-9 expression. Histopathologically, a large pool of secreted acid/neutral mucopolysaccrides as well as the presence of blood vessels and dysplastic crypts signifies invasive mucinous adenocarcinoma while both the drugs reduced these neoplastic alterations. Wnt/β-catenin pathway was also found to be up-regulated which served as a crucial indicator for cancer cell growth. A concomitant down regulation of PPARγ was noted in DMH treatment which is associated with tumor progression. The expression of PPARα and δ, the other two isoforms of PPAR family was also modulated. We conclude that piroxicam and c-phycocyanin exert their anti-neoplastic effects via regulating membrane properties, raising calpain-9 and PPARγ expression while suppressing Wnt/β-catenin signaling in experimental colon carcinogenesis.

Topics: 2-Naphthylamine; Animals; Apoptosis; Calcium; Calpain; Carcinogenesis; Colonic Neoplasms; Fluorescence Polarization; Fura-2; Intracellular Space; Laurates; Ligands; Male; Membrane Fluidity; Membrane Potentials; Phase Transition; Phosphatidylethanolamines; Phycocyanin; Piroxicam; PPAR gamma; Pyrimidinones; Rats, Sprague-Dawley; Up-Regulation; Wnt Signaling Pathway

The p21-activated kinases (PAKs) are immediate downstream effectors of the Rac/Cdc42 small G-proteins and implicated in promoting tumorigenesis in various types of cancer including breast and lung carcinomas. Recent studies have established a requirement for the PAKs in the pathogenesis of Neurofibromatosis type 2 (NF2), a dominantly inherited cancer disorder caused by mutations at the NF2 gene locus. Merlin, the protein product of the NF2 gene, has been shown to negatively regulate signaling through the PAKs and the tumor suppressive functions of Merlin are mediated, at least in part, through inhibition of the PAKs. Knockdown of PAK1 and PAK2 expression, through RNAi-based approaches, impairs the proliferation of NF2-null schwannoma cells in culture and inhibits their ability to form tumors in vivo. These data implicate the PAKs as potential therapeutic targets. High-throughput screening of a library of small molecules combined with a structure-activity relationship approach resulted in the identification of FRAX597, a small-molecule pyridopyrimidinone, as a potent inhibitor of the group I PAKs. Crystallographic characterization of the FRAX597/PAK1 complex identifies a phenyl ring that traverses the gatekeeper residue and positions the thiazole in the back cavity of the ATP binding site, a site rarely targeted by kinase inhibitors. FRAX597 inhibits the proliferation of NF2-deficient schwannoma cells in culture and displayed potent anti-tumor activity in vivo, impairing schwannoma development in an orthotopic model of NF2. These studies identify a novel class of orally available ATP-competitive Group I PAK inhibitors with significant potential for the treatment of NF2 and other cancers.

Topics: Animals; Carcinogenesis; Catalytic Domain; Cell Proliferation; Drug Discovery; Humans; Mice; Models, Molecular; Neurilemmoma; Neurofibromatosis 2; p21-Activated Kinases; Protein Kinase Inhibitors; Pyridones; Pyrimidines; Pyrimidinones; Small Molecule Libraries