Publications by authors named "Hiroharu Arakawa"

Wee1 is a tyrosine kinase that phosphorylates and inactivates CDC2 and is involved in G(2) checkpoint signaling. Because p53 is a key regulator in the G(1) checkpoint, p53-deficient tumors rely only on the G(2) checkpoint after DNA damage. Hence, such tumors are selectively sensitized to DNA-damaging agents by Wee1 inhibition.

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The replacement of 1,3-dihydroxy-2-propylamino moiety at the N6-position of edotecarin (1) by arylmethylamino groups yielded a number of more potent topoisomerase I inhibitors with better cytotoxic (CTX) activities in vitro than edotecarin. Among them, the three most potent pyridylmethyl analogues, compounds 22g, 22m, and 23c, showed better antitumor activities against MKN-45 human stomach cancer or MX-1 human breast cancer xenografted mice than those of edotecarin. Furthermore, compounds 22m and 23c exhibited complete response against MX-1 cells implanted in mice.

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Article Synopsis
  • The study focuses on the ABCG2 half-transporter, which is linked to resistance against certain chemotherapy drugs, including indolocarbazole derivatives, in cancer cells.
  • Researchers compared two versions of ABCG2 (wild type 482R and mutant 482T) to see how they impacted cross-resistance patterns, finding both types conferred strong resistance to indolocarbazoles.
  • The transport mechanism of indolocarbazole compound A was further explored, showing it was actively transported in cells and that its movement was energy-dependent, suggesting distinct binding sites and transport mechanisms for other drugs like mitoxantrone.
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Purpose And Experimental Design: We previously reported that an increased expression of cystatin-like metastasis-associated protein (CMAP) mRNA is involved in liver-specific metastasis in a mouse model. We also identified its human homologue and showed that the expression of CMAP in various human cancer cell lines correlated with the description of malignancy in these cell lines. However, there is still no information available on the clinical significance of CMAP expression in human cancer specimens.

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