Catechin, green tea component, causes caspase-independent necrosis-like cell death in chronic myelogenous leukemia

Management strategies of chronic phase chronic myelogenous leukemia (CML) have been revolutionized due to the discovery of a selective tyrosine kinase inhibitor, imatinib (Gleevec, STI571), which is substantially improving median survival. However, emergence of imatinib-resistance has put up a serious problem that requires novel treatment methods. Catechins, polyphenolic compounds in green tea, are gathering much attention due to their potential antitumor effects. So far (–)-epigallocatechin-3-gallate (EGCG), the most abundant component of catechin, has been shown to cause typical apoptosis in several tumor cell lines in most cases through activation of caspases. In this study, we showed that EGCG predominantly caused necrosis-like cell death via a caspase-independent mechanism in CML cells, K562 and C2F8, whereas imatinib induced the typical apoptotic cell death. Moreover, this caspase-independent cell death partially mediated the release of apoptosis-inducing factor, AIF, and serine protease, HtrA2/Omi, from the mitochondria to cytosol. In addition, EGCG enhanced the imatinib-induced cell death ( P <  0.01) resulting in additive cell death in K562 cells and EGCG alone, effectively reduced the viability of imatinib-resistant K562 cells ( P <  0.01). Catechin is a possible candidate for an antitumor agent that causes cell death in CML cells via a caspase-independent mechanism. ( Cancer Sci 2009; 100: 349–356)     

Clinically relevant dose of zoledronic acid inhibits spontaneous lung metastasis in a murine osteosarcoma model

Clinically obtainable concentrations of zoledronic acid (ZOL) inhibited the production of vascular endothelial growth factor and reduced the migration, adhesion, and invasiveness of osteosarcoma (OS) cells in vitro. The in vivo effects of ZOL were investigated by using a murine model of spontaneous lung metastasis. The higher dose of ZOL (80 microg/kg three times/week) inhibited the growth of OS at the primary site, accompanied by inhibition of neovascularization in the tumor. Interestingly, while the lower dose of ZOL (80 microg/kg once a week) could not inhibit the growth of OS at the primary site, it significantly prevented lung metastasis.     

PAX5 alterations in an infant case of KMT2A‐rearranged leukemia with lineage switch

Lineage switch is a rare event at leukemic relapse. While mostly known to occur in KMT2A‐rearranged infant leukemia, the underlying mechanism is yet to be depicted. This case report describes a female infant who achieved remission of KMT2A‐MLLT3‐rearranged acute monocytic leukemia, but 6 months thereafter, relapsed as KMT2A‐MLLT3‐rearranged acute lymphocytic leukemia. Whole exome sequencing of the bone marrow obtained pre‐post lineage switch revealed two somatic mutations of PAX5 in the relapse sample. These two PAX5 alterations were suggested to be loss of function, thus to have played the driver role in the lineage switch from acute monocytic leukemia to acute lymphocytic leukemia.     

A Case of Leiomyosarcoma Associated with Humoral Hypercalcemia of Malignancy: Demonstration of Biological and Immunological Activities of Parathyroid Hormone-related Protein in the Tumor Extract

Hypercalcemia occurred in a patient with leiomyosarcoma when multiple lung metastases developed. Despite normal plasma parathyroid hormone (PTH) levels and low 1,25-dihydroxyvitamin D, this hypercalcemic patient had a marked hypercakiuria and phosphatnria associated with an increased excretion of nephrogenous cyclic AMP (NcAMP). Administration of cisplatin ameliorated both the hypercalcemia and hypercalciuria without any reduction in tumor size or NcAMP excretion. Terminally, acute pancreatitis occurred producing a profound hypocalcemia. In the extract of tumor tissue obtained post mortem, bioactivity stimulating the generation of cyclic AMP in osteogenic cells was demonstrated along with the immunoreactive PTH-related protein (PTH-rP). This is the first report of a solid non-epithelial malignancy producing PTH-rP and associated with humoral hypercalcemia of malignancy. The hypercalcemia in this case caused acute pancreatitis, which led to a profound hypocalcemia     

Apoptotic process of cerebellar degeneration in experimental methylmercury intoxication of rats

This report deals with the mechanism involved in the cerebellar degeneration following experimental methylmercury poisoning of male Wistar rats. The cerebellar granule cells of animals that exhibited typical hind leg paresis were shrunken and displayed marked nuclear pyknosis. At the ultrastructural level, the nuclei of these cells were condensed and fragmented, features which are characteristic of apoptosis. In situ staining for DNA strand breaks revealed that the pyknotic nuclei were positively labeled. DNA fragmentation was confirmed by agarose gel electrophoresis; a ladder pattern of multiples of approximately 200-base pair fragments, typical of apoptosis, was observed with the cerebellar DNA of the methylmercury-treated animals. These observations suggest that the degeneration of cerebellar granule cells by alkyl mercury compounds involves an apoptotic process. Received: 21 June 1995 / Revised, accepted: 11 September 1995     

Endocrinology: Reduced implantation rate associated with a subtle rise in serum progesterone concentration during the follicular phase of cycles stimulated with a combination of a gonadotrophin-releasing hormone agonist and gonadotrophin

Our objective was to assess the effects of subtle increasesin serum progesterone concentration (1.0–2.0 ng/ml) onthe outcome of in-vitro fertilization (IVF), particularly onthe quality of embryos, during the follicular phase of cyclesstimulated with gonadotrophin-releasing hormone agonist (GnRHa)and human menopausal gonadotrophin (HMG). A total of 97 patientsunderwent 116 cycles of IVF and were stimulated with a combinationof HMG and GnRHa. They were divided into two groups: those witha subtle progesterone rise and those with no progesterone rise.The two groups were compared with respect to serum oestradiol,progesterone, immunoreactive luteinizing hormone (I-LH), bioactiveLH (B-LH), and results of IVF. The groups did not differ significantlyin mean age or in total dose of HMG received. On the day thathuman chorionic gonadotrophin was administered, concentrationsof oestradiol and progesterone were significantly higher inthe subtle progesterone rise cycles than in the no progesteronerise cycles. In the no progesterone rise cycles, the percentagesfor embryos beyond the 4-cell stage, grade 1 embryos, and implantationrates were significantly higher than those in subtle progesteronerise cycles. The combination of GnRHa and HMG eliminated anysignificant rise in serum I-LH or B-LH concentration duringthe follicular phase, but did not suppress the subtle rise inprogesterone. These results confirm our previous finding thata subtle progesterone rise adversely affects the outcome ofIVF. It is also suggested that a reduction in embryo qualitymay influence the lower rate of implantation in subtle progesteronerise cycles.