TAC-101 (4-[3,5-bis(trimethylsilyl)benzamido]benzoic acid) inhibits spontaneous mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma

A phase I/II trial of TAC-101, an oral synthetic retinoid, in patients with advanced hepatocellular carcinoma

PURPOSE

Preclinical models showed TAC-101 (4-[3,5-bis(trimethylsilyl) benzamide] benzoic acid), an oral synthetic retinoid, has anti-tumor activity in hepatocellular carcinoma (HCC). A phase I/II study was performed in advanced HCC patients (pts).

PATIENTS AND METHODS

Thirty-three patients were enrolled. During Phase I, pts received 40 mg daily for 14 days q3 weeks; 2 of 5 patients developed DLT so dose was reduced to 20 mg/day. Twenty-eight patients received 20 mg/day.

RESULTS

No pt had a CR or PR, but 12 of 21 (57%) had SD. Two pts (9.5%) had late PR after discontinuing TAC-101. Median survival (MS) for all 28 pts treated with 20 mg/day was 12.7 months (95% CI 8.8-22.7); MS for 21 evaluable pts was 19.2 months (95% CI 10.4-27.6).

CONCLUSIONS

20 mg of TAC- was well tolerated. Significant disease stabilization (12/21 pts, 57%), 2 late PRs, and prolonged MS (19.2 months) suggest that TAC-101 provides meaningful patient benefit.

Syngeneic lymph-node-targeting model of green fluorescent protein-expressing Lewis lung carcinoma

The Lewis lung tumor has been extensively studied in both syngeneic and allogeneic mouse models. However, its metastatic potential and mechanism are poorly understood. The aim of the present study was to develop a highly metastatic lymph-node targeting, imageable model of the Lewis lung carcinoma in a syngeneic host. We report here a syngeneic model of the Lewis lung carcinoma in which the carcinoma cells are labeled with green fluorescent protein (GFP). The tumor cells were transplanted in the dorsal side of the ear of C57-B16 mice in order to give the tumor cells access to the lymphatic system. This model of the Lewis lung carcinoma extensively metastasized to numerous lymph nodes throughout the body of the animal as well as visceral organs, as visualized by fluorescence microscopy using the bright GFP signal. Twenty-one different metastatic sites, including lymph nodes throughout the body, were identified among the cohort of transplanted animals. The data demonstrate a predilection of the Lewis lung carcinoma for lymphatic pathways for metastasis throughout the animal body. The concomitant macrometastases to the visceral organs observed in this model may be remetastasis from the lymph nodes. This model of the Lewis lung carcinoma should be very useful in defining cellular trafficking and targeting mechanisms of metastasis, in particular those involving lymphatic pathways.

TAC-101 inhibits intrahepatic metastasis of orthotopically implanted murine hepatocellular carcinoma

The anti-metastatic effect of 4-[3,5-bis(trimethylsilyl)benzamido]benzoic acid (TAC-101) was investigated using our established intrahepatic metastasis model. Orthotopic implantation of a fragment of CBO140C12 hepatoma into the liver resulted in the formation of a solitary tumor nodule and its intrahepatic metastasis. Daily oral administration of TAC-101 at a dose of 8 mg/kg resulted in a significant inhibition of intrahepatic metastasis, but did not affect the growth of the tumor at the implanted site. The down-regulation of transcriptional anti-activator protein-1 (AP-1) activity by TAC-101 paralleled the inhibition of cell invasion and migration through the repression of expression of the mRNAs for urokinase-type plasminogen activator (u-PA) and its receptor (u-PAR). These findings suggest that TAC-101 may improve therapeutic efficacy for liver cancer patients to prevent intrahepatic metastasis.

Multifunctional anti-angiogenic activity of the cyclic peroxide ANO-2 with antitumor activity

Our focus was to develop an anti-angiogenic drug possessing the inhibitory activity of urokinase-type plasminogen activator (u-PA) production. During preliminary screening, the effects of 13 ozonides on the inhibition of u-PA production in human fibrosarcoma HT-1080 cells and on the inhibition of angiogenesis on chicken embryonic chorioallantoic membranes were determined. Of the ozonides tested, 9 inhibited in vitro u-PA production of HT-1080 cells and 7 of these 9 exhibited strong anti-angiogenic activity. Interestingly, 6 of the 13 ozonides also inhibited cathepsin B activity. 1-Phenyl-1, 4-epoxy-1H,4H-naphtho[1,8-de][1, 2]dioxepin (ANO-2) potently inhibited cathepsin B (IC(50) = 0.47 microM) as well as u-PA production. Consequently, ANO-2 was selected for further study. ANO-2 inhibited tube formation by human umbilical vein endothelial cells cultured on Matrigel while exhibiting no cytotoxicity. Additionally, in vivo administration of ANO-2 inhibited angiogenesis induced by mouse Sarcoma-180 cells tested using the mouse dorsal air sac assay. Moreover, ANO-2 also suppressed primary tumor growth and reduced the number of pulmonary metastases caused by Lewis lung carcinoma cells in mice. These in vitro and in vivo activities indicate that ANO-2 has considerable potential as a new and potent anti-angiogenic drug that inhibits both u-PA production and enzymatic activity of cathepsins, indicating that ANO-2 may be a multifunctional inhibitor of angiogenesis.

Regulation of activator protein-1 activity in the mediastinal lymph node metastasis of lung cancer

Orthotopic implantation of a metastatic cell line of Lewis lung carcinoma (LLC-MLN), which was isolated by an in vivo selection method, resulted in greater metastatic growth in mediastinal lymph nodes as compared with that of the original LLC cells. LLC-MLN cells also had increased invasive ability and activator protein-1 (AP-1) transcriptional activity as compared with the original LLC cells. This is well consistent with the previously reported finding that overexpression of AP-1 is associated with lymphatic metastasis in lung cancer patients. Oral administration of curcumin, which downregulates AP-1 transcription, significantly inhibited the mediastinal lymph node metastasis of orthotopically implanted LLC cells in a dose-dependent manner, but did not affect the tumor growth at the implantation site. Combined treatment with curcumin and an anti-cancer drug, cis-diamine-dichloroplatinum (CDDP), resulted in a marked inhibition of tumor growth at the implanted site and of lymphatic metastasis, and a significant prolongation of the survival time. The downregulation of transcriptional AP-1 activity by curcumin as seen in the dual luciferase assay caused inhibition of LLC cell invasion through the repression of expression of the mRNAs for urokinase-type plasminogen activator (u-PA) and its receptor (u-PAR). Inhibition of AP-1 transcriptional activity may offer improved therapeutic efficacy for lung cancer patients with lymphatic metastasis.

Inhibitory effect of berberine on the mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma

We examined the effect of berberine, a major component with anti-fungal properties contained in Coptidis Rhizoma and Phellodendri Cortex, on the lymph node metastasis of murine lung cancer. Oral administration of berberine for 14 days significantly inhibited the spontaneous mediastinal lymph node metastasis produced by orthotopic implantation of Lewis lung carcinoma (LLC) into the lung parenchyma in a dose-dependent manner, but did not affect the tumor growth at the implantation site of the lung. Combined treatment with berberine and an anti-cancer drug, CPT-11, resulted in a marked inhibition of tumor growth at the implantation site and of lymphatic metastasis, as compared with either treatment alone. Anti-activator protein-1 (anti-AP-1) transcriptional activity of non-cytotoxic concentrations of berberine caused the inhibition of the invasiveness of LLC cells through the repression of expression of urokinase-type plasminogen activator (u-PA).