Cancer Cell & Microenvironment 2015; 2: e886. doi: 10.14800/ccm.886; © 2015 by Hirota Fujiki, et al. http://www.smartscitech.com/index.php/ccm

REVIEW

Innovative strategy of cancer treatment with the combination of green tea catechins and anticancer compounds Hirota Fujiki1, Kazue Imai2, Kei Nakachi2, Eisaburo Sueoka1, Tatsuro Watanabe1, Masami Suganuma3 1

Department of Clinical Laboratory Medicine, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan Radiation Effects Research Foundation, 5-2 Hijiyamakoen, Minami-ku, Hiroshima 732-0815, Japan 3 Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan 2

Correspondence: Hirota Fujiki E-mail: [email protected] Received: June 27, 2015 Published online: August 13, 2015

Human cancer development involves durable genetic changes caused by carcinogens, pro-inflammatory cytokines and chemokines, and simultaneous inflammation in cancer microenvironment. Green tea containing non-toxic anti-inflammatory green tea catechins is an acknowledged cancer preventive. This paper first introduces two results that 10 Japanese-size-cups (150 ml/cup) of green tea per day delayed cancer onset in primary cancer prevention and daily green tea supplemented with tablets of green tea extract equivalent to 10 cups prevented colorectal adenoma recurrence in tertiary cancer prevention. The results allowed us to find synergistic anticancer effects in both in vitro and in vivo experiments with the combinations of (-)-epigallocatechin gallate (EGCG) or green tea extract and two non-steroidal anti-inflammatory drugs (NSAIDs), such as sulindac and celecoxib. We next collected the results of numerous investigators as follows: the combinations of EGCG and 37 anticancer compounds, which include NSAIDs, phytochemicals, and anticancer drugs, generally induced in vitro synergistic anticancer effects on 54 human cancer cell lines derived from various cancer tissues, and the combinations of EGCG, or green tea extract and 13 anticancer compounds showed reduction of tumor volume in xenograft mouse models implanted using various human cancer cell lines. For example, average reduction of tumor volume with combinations, anticancer compounds alone, EGCG alone, or vehicle for control were 70.3%, 33.7%, 26.5%, or 0%, respectively. Especially, the complete elimination of tumor development on human prostate cancer cell line PC-3ML was found in xenograft mouse models treated with combinations of EGCG and paclitaxel, and EGCG and docetaxel. The amount of EGCG necessary for complete elimination of tumor in mice corresponds to 6 - 9 cups of green tea for humans. Moreover, the combination was reported to inhibit stem cell characteristics. The combination resulting in 70.3% reduction of tumor volume makes it possible to innovate cancer treatment, and the cancer patient could achieve improved quality of life without suffering the side effects of anticancer drugs, which results in “the final goal of cancer therapy is the survival of cancer patients with coexistence of cancer cells” presented by Prof. Tomizo Yoshida, a mentor of Japanese pathologists. Keywords: Cancer onset; Combination; EGCG; GADD153; Recurrence of colon polyps To cite this article: Hirota Fujiki, et al. Innovative strategy of cancer treatment with the combination of green tea catechins and anticancer compounds. Can Cell Microenviron 2015; 2: e886. doi: 10.14800/ccm.886.

Introduction Drinking green tea daily is part of Japanese lifestyle.

Green tea contains at least four green tea catechins, and (-)-epigallocatechin gallate (EGCG) is the main constituent. Our first indication of EGCG as a cancer preventive agent is

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Cancer Cell & Microenvironment 2015; 2: e886. doi: 10.14800/ccm.886; © 2015 by Hirota Fujiki, et al. http://www.smartscitech.com/index.php/ccm

based on evidence showing that EGCG prevented tumor promotion of both teleocidin, one of the 12-O-tetradecanoylphorbol-13-acetate (TPA) type-tumor promoters and okadaic acid, a strong inhibitor of protein phosphatases 1 and 2A, on mouse skin initiated with 7,12-dimethylbenz[a]anthracene (DMBA) in two-stage carcinogenesis experiments [1, 2]. In light of evidence that tumor promoters of the okadaic acid class, such as okadaic acid, dinophysistoxin-1, calyculin A, microcystin-LR and nodularin induced tumor promoting activity on three different organs, such as mouse skin, rat glandular stomach and rat liver [3], the results allowed us to discover TNF- as a general tumor promoter in various organs [4, 5], and to engender the concept of endogenous tumor promoters representing cytokines and chemokines in tumor promotion and progression [6]. Considering the results that EGCG and green tea extract prevented carcinogenesis in a wide range of target organs in rodents [7], and that green tea catechins generally act as cancer preventive agents through inhibition of inflammation [8, 9], the prospective cohort study of 8,552 individuals in Saitama Prefecture revealed that drinking 10 Japanese-size cups (150 ml/cup; estimated concentration of EGCG being 20-29 mg/100 ml [10]) of green tea per day delayed the cancer onset of humans 6.2 years for females [11], and that drinking 10 cups of green tea supplemented with green tea tablets significantly prevented 51.6% in recurrence of colorectal adenomas of patients [12]. These exciting results prompted us to think that green tea catechins together with anticancer agents are effective cancer treatments, and to move from cancer prevention with green tea to a new strategy of cancer treatment. We found that the combinations of EGCG and sulindac, or EGCG and celecoxib strongly stimulated both induction of apoptosis and expression of growth arrest and DNA damage-inducible gene 153 (GADD153) in human lung cancer cell line PC-9 [13-15], and that the combinations synergistically inhibited rodent carcinogenesis experiments [16, 17]. Furthermore numerous reports of other investigators demonstrated that combinations of green tea catechins and various anticancer compounds induced in vitro and in vivo synergistic anticancer effects on numerous human cancer cell lines. We now present the combinations of EGCG or green tea mixture and anticancer compounds as an innovative strategy of cancer treatment, inhibiting initiation and tumor promotion and progression, which will achieve improved quality of life in cancer patients [18]. Delay of cancer onset The prospective cohort study of Nakachi et al. at Saitama Cancer Center Research Institute surveyed 8,552 individuals in Saitama Prefecture aged over 40 on their living habits, and found a total of 488 cancer patients, 203 females and 285

males for 11 years from 1986 to 1997 [11]. These 488 cancer patients were surveyed at baseline from 1986 and analyzed in terms of the daily consumption of green tea (three categories: under 3 cups, 4 to 9 cups and over 10 cups) and the ages at cancer onset. Average age of cancer onset in female patients who had consumed over 10 cups of green tea per day was 6.2 years later than that of patients who had consumed less than three cups per day, and in male patients who consumed over 10 cups of green tea per day it was 3.2 years later than that of patients who had consumed less than three cups per day [11] (Table 1). The difference between females and males may be partly due to higher tobacco consumption by males. In addition, green tea most significantly prevented lung cancer a relative risk of 0.33 with over 10 cups of green tea per day. High consumption of green tea also prevented cancers of the colorectum, liver and stomach, in that order [11]. This was the significant finding showing that drinking 10 cups of green tea per day results in delay of cancer onset among the general population in primary cancer prevention. The results allowed us to think that green tea catechins in 10 cups of green tea are the cancer preventive amount of green tea for humans [9]. Green tea is now an acknowledged cancer preventive in Japan. When we looked at the previous results of this cohort study with 384 cancer patients (164 females and 220 males) among 8,552 individuals found in 9-year follow-up of 1986 through 1995, average age at cancer onset in female patients (12.8%) in the highest category of green tea consumption was 8.7 years later than that of patients (29.9%) in the lowest category of green tea consumption, and in male patients, the delay of cancer onset was 3.0 years similar as that of 11-year follow-up [10]. The delay of cancer onset in females was further confirmed by an analysis of age-specific cancer incidence rates: An obvious slowdown in the increase of cancer incidence with age, especially in ages < 80 among those consuming the most green tea, compared with those consuming the least green tea [10]. It is evident that female patients who consumed over 10 cups of green tea per day significantly delayed cancer onset in the survey of both 9 and 11 years [10, 11]. Prevention of colorectal adenoma recurrence As Table 1 shows, the percentage of cancer patients who had consumed over 10 cups of green tea per day was 13.8% for females and 30.2% for males. We think that if the average adult consumes daily the same amount of green tea catechins, we can achieve cancer prevention for most Japanese. In order to conduct cancer prevention trial with 10 cups of green tea per day, the tablets of green tea extract (G.T.E) were produced from the dried powder of green tea infusion by the Green Tea Laboratory of Saitama

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Cancer Cell & Microenvironment 2015; 2: e886. doi: 10.14800/ccm.886; © 2015 by Hirota Fujiki, et al. http://www.smartscitech.com/index.php/ccm Table 1. Average age at cancer onset and daily green tea consumption Gender

Consumption of green tea per day (cups) ≦3

Female Average age at cancer onset No. of patients (a total of 203) Male Average age at cancer onset No. of patients (a total of 285)

≧10

68.3 ± 1.6

4〜9 67.5 ± 1.1

74.5 ± 2.0

（58）

（117）

（28）

65.7 ± 0.6

68.0 ± 0.9

68.9 ± 1.0

(69)

（130）

（86）

(Nakachi et al., BioFactors 2000)

Table 2. Phase II prevention trial of colorectal adenoma recurrence in patients with 10 cups of green tea supplemented with G.T.E Groups (cases) Control group (20/65) G.T.E group ( 9/60)

Recurrence rate (%) 31.0 15.0 P