The currently available chemotherapeutic regimens against gastric cancer are not very effective, leading to high recurrence and poor survival. Resveratrol is a naturally occurring polyphenol with potent apoptosis-inducing activity. However, the mechanism underlying its actions remains unknown. In the present study, human gastric adenocarcinoma SGC7901 cells were treated with resveratrol (0, 25, 50, 100 and 200 μmol/L) for 48 h, and cellular apoptosis DNA damage were determined. In certain experiments, cells were incubated with superoxide dismutase (100 U/mL), catalase (300 U/mL) or sirtinol (10 μmol/L) to determine the role of reactive oxygen species (ROS) and sirtuin1 in resveratrol-induced cellular apoptosis. Treatment with resveratrol (50-200 μmol/L) for 48 h significantly induced apoptosis and DNA damage in human gastric cancer SGC7901 cells. This was due to the increased generation of ROS following resveratrol treatment because incubation of cells with superoxide dismutase (100 U/mL) or catalase (300 U/mL) attenuated resveratrol-induced cellular apoptosis. Interestingly, treatment with resveratrol (25-200 μmol/L) did not affect the level and activity of sirtuin1, whereas the sirtuin1 inhibitor sirtinol (10 μmol/L) significantly reduced sirtuin1 activity. Furthermore, treatment with sirtinol (10 μmol/L) did not have any effect on apoptosis induced by resveratrol. These data provide evidence that resveratrol induces apoptosis via ROS, but independent of sirtuin1, in the human gastric cancer cell line SGC7901.
Hericium is a genus of mushrooms (fungus) in the Hericiaceae family. Hericium erinaceus (HE) has been used for the treatment of digestive diseases for over 2000 years in China. HE possesses many beneficial functions such as anticancer, antiulcer, antiinflammation and antimicrobial effects, immunomodulation and other activities. The aim of the studies was to evaluate the anticancer efficacy of two extracts (HTJ5 and HTJ5A) from the culture broth of HE against three gastrointestinal cancers such as liver, colorectal and gastric cancers in both of in vitro of cancer cell lines and in vivo of tumor xenografts and discover the active compounds.
MATERIALS AND METHODS:
Two HE extracts (HTJ5 and HTJ5A) were used for the studies. For the study of chemical constituents, the HTJ5 and HTJ5A were separated using a combination of macroporous resin with silica gel, HW-40 and LH-20 chromatography then purified by semipreparative high-performance liquid chromatography (HPLC) and determined by nuclear magnetic resonance (NMR) spectra. For the in vitro cytotoxicity studies, HepG2 and Huh-7 liver, HT-29 colon, and NCI-87 gastric cancer cell lines were used and MTT assay was performed to determine the in vitro cytotoxicity. For in vivo antitumor efficacy and toxicity studies, tumor xenograft models of SCID mice bearing liver cancer HepG2 and Huh-7, colon cancer HT-29 and gastric cancer NCI-87 subcutaneously were used and the mice were treated with the vehicle control, HTJ5 and HTJ5A orally (500 and 1000mg/kg/day) and compared to 5-fluorouraci (5-FU) at the maximum tolerated dose (MTD, 25-30mg/kg/day) intraperitoneally daily for 5 days when the tumors reached about 180-200mg (mm(3)). Tumor volumes and body weight were measured daily during the first 10 days and 2-3 times a week thereafter to assess the tumor growth inhibition, tumor doubling time, partial and complete tumor response and toxicity.
Twenty-two compounds were obtained from the fractions of HTJ5/HTJ5A including seven cycli dipeptides, five indole, pyrimidines, amino acids and derivative, three flavones, one anthraquinone, and six small aromatic compounds. HTJ5 and HTJ5A exhibited concentration-dependent cytotoxicity in vitro against liver cancer HepG2 and Huh-7, colon cancer HT-29, and gastric cancer NCI-87 cells with the IC50 in 2.50±0.25 and 2.00±0.25, 0.80±0.08 and 1.50±0.28, 1.25±0.06 and 1.25±0.05, and 5.00±0.22 and 4.50±0.14mg/ml; respectively. For in vivo tumor xenograft studies, HTJ5 and HTJ5A showed significantly antitumor efficacy against all four xenograft models of HepG2, Huh-7, HT-29 and NCI-87 without toxicity to the host. Furthermore, HTJ5 and HTJ5A are more effective than that of 5-FU against the four tumors with less toxicity.
HE extracts (HTJ5 and HTJ5A) are active against liver cancer HepG2 and Huh-7, colon cancer HT-29 and gastric cancer NCI-87 cells in vitro and tumor xenografts bearing in SCID mice in vivo. They are more effective and less toxic compared to 5-FU in all four in vivo tumor models. The compounds have the potential for development into anticancer agents for the treatment of gastrointestinal cancer used alone and/or in combination with clinical used chemotherapeutic drugs. However, further studies are required to find out the active chemical constituents and understand the mechanism of action associated with the super in vivo anticancer efficacy. In addition, future studies are needed to confirm our preliminary results of in vivo synergistic antitumor efficacy in animal models of tumor xenografts with the combination of HE extracts and clinical used anticancer drugs such as 5-FU, cisplatin and doxurubicin for the treatment of gastrointestinal cancers.
Treatment of gastric cancer remains a major challenge, and new anticancer drugs are urgently required. This study investigated whether dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, could inhibit the growth of gastric cancer both in vitro and in vivo. A series of in vitro experiments including MTT, colony-forming, wound healing, invasion, cell cycle, cellular senescence, and apoptosis assays were performed to examine the antiproliferative and antimetastatic effects of DHA on three gastric cancer cell lines, SGC-7901, BGC823, and MGC803. The result showed that the proliferation rate and colony-forming abilities of gastric cancercells were significantly suppressed by DHA together with significant suppression of the expressions of proliferation markers (PCNA, cyclin E, and cyclin D1), and upregulation of p21 and p27.
Moreover, DHA induced cellular senescence, G1 phase cell cycle arrest and hindered the migration and invasion of gastric cancer cells corresponding with downregulation of MMP-9 and MMP-2. Furthermore, DHA significantly induced apoptosis through suppressing Bcl-2 as well as activating caspase-9 and PARP. Treatment of gastric cancer cells with DHA increased miR-15b and miR-16 expression, caused a downregulation of Bcl-2, resulting in apoptosis of gastric cancer cells. In vivo, our data showed that DHA significantly inhibited the growth of SGC7901 cell-transplanted tumors. In summary, we have shown that DHA is able to inhibit the growth and metastasis of human gastric cancer. The modulation of miR-15b and miR-16 mediated the apoptosis effects of DHA in gastric cancer cells. Our work suggested that DHA has significant anticancer effects against gastric cancer both in vivo and in vitro, indicating that it is a promising therapy for human gastric cancer.
Tratamentele chemoterapice disponibile în mod curent împotriva cancerului gastric nu sunt foarte eficiente, ducând la recidive şi slabă supravieţuire. Resveratrolul este un polifenol apărut pe cale naturală cu puternică acţiune de inducere a apoptozei. Cu toate acestea mecanismele care stau la baza acţiunilor sale rămân necunoscute. În studiul prezent celule ale adenocarcinomului uman gastric SGC7901au fost tratate cu resveratrol (0,25, 50, 100 şi 200 µmol/L) pentru 48 de ore, şi a fost determinată distrugerea ADN-ului prin apoptoză celulară. În anumite experimente unele celule au fost incubate cu superoxid dismutază (100 U/ml), catalază (300 U/ml) sau sirtinol (10 µmol/L) pentru a determina rolul speciilor de oxigen reactive (ROS) şi a sirtuinei1 în apoptoza celulară indusă de resveratrol. Tratamentul cu resveratrol (50-200 µmol/L) timp de 48 de ore a indus semnificativ apoptoza şi distrugerea ADN-ului la celulele de cancer uman gastric SGC7901. Aceasta a fost datorită generaţiilor mărite de ROS care au urmat tratamentului cu resveratrol, deoarece incubaţia celulelor cu superoxid distutază (100 U/ml) sau catalază (300 U/ml) a atenuat apoptoza celulară indusă de resveratrol. În mod interesant, tratamentul cu resveratrol (25-200 µmol/L) nu a afectat nivelul şi activitatea sirtuinei1, în timp ce inhibitorul de sirtuină1, sirtinol (10 µmol/L), a redus semnificativ activitatea sirtuinei1. Mai mult, tratamentul cu sirtinol (10 µmol/L) nu a avut nici un efect asupra apoptozei indusă de resveratrol. Aceste date furnizează probe că resveratrolul induce apoptoza via ROS, dar independent de sirtuina1, la linia celulară a cancerului gastric uman SGC7901.
Tratamentul cancerului gastric rămâne o provocare majoră, şi se impune găsirea unor noi medicamente anti-cancer cât mai curând posibil. Acest studiu investighează faptul dacă dihidroartemisininul (DHA), un derivat semi-sintetic al artemisininului, poate inhiba dezvoltarea cancerului gastric atât in vivo cât şi in vitro. Au fost desfăşurate o serie de experimente in vitro, incluzând MTT, formarea de colonii, vindecarea unor răni, invazie, ciclu celular, îmbătrânire celulară şi teste de apoptoză, pentru a examina efectele anti-proliferative şi anti-metastatice ale DHA asupra a trei linii celulare ale cancerului gastric, SGC-7901, BGC823 şi MGC803. Rezultatele au arătat că rata de proliferare şi abilitatea de a forma colonii ale celulelor canceroase gastrice au fost semnificativ supresate de DHA odată cu o supresare semnificativă a expresiei markerilor de proliferare (PCNA, ciclina E şi ciclina D1) şi hiperreglarea lui p21 şi p27.
Mai mult decât atât, DHA a indus senescenţă celulară, stoparea ciclului celular în faza G1 şi a împiedicat migraţia şi invazia celulelor canceroase gastrice cu hiporeglarea lui MMP-9 şi MMP-2. În plus, DHA a indus semnificativ apoptoza prin supresarea Bcl-2 ca şi prin activarea caspazei 9 şi PARP. Tratamentul celulelor gastrice cu DHA a crescut expresia miR-15b şi miR-16 şi a cauzat o hiporeglare a Bcl-2, rezultând apoptoza celulelor canceroase gastrice. In vivo datele noastre au arătat că DHA a inhibat semnificativ tumorile cu celule SGC7901, transplantate. În rezumat am arătat că DHA este capabil să inhibe dezvoltarea şi metastazele cancerului gastric uman. Modularea miR-15b şi miR-16 a mediat efectele de apoptoză ale DHA în celulele canceroase gastrice. Munca noastră sugerează că DHA are efecte semnificative anti-cancer asupra cancerului gastric atât in vivo cât şi in vitro, indicându-l ca pe un tratament promiţător pentru cancerul gastric la oameni.