L-ascorbic acid (L-AA; vitamin C) induces apoptosis in cancer cells. This study aimed to elucidate the molecular mechanisms of L-AA-induced apoptosis in human laryngeal epidermoid carcinoma Hep-2 cells. L-AA suppressed the viability of Hep-2 cells and induced apoptosis, as shown by the cleavage and condensation of nuclear chromatin and increased number of Annexin V-positive cells. L-AA decreased Bcl-2 protein expression but upregulated Bax protein levels. In addition, cytochrome c release from the mitochondria into the cytosol and activation of caspase-9, -8, and -3 were enhanced by L-AA treatment. Furthermore, apoptosis-inducing factor (AIF) and endonuclease G (EndoG) were translocated into the nucleus during apoptosis of L-AA-treated Hep-2 cells. L-AA effectively inhibited the constitutive nuclear factor-κB (NF-κB) activation and attenuated the nuclear expression of the p65 subunit of NF-κB. Interestingly, L-AA treatment of Hep-2 cells markedly activated Akt and mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase [JNK]) and and LY294002 (Akt inhibitor), SB203580 (p38 inhibitor) or SP600125 (a JNK inhibitor) decreased the levels of Annexin V-positive cells. These results suggested that L-AA induces the apoptosis of Hep-2 cells via the nuclear translocation of AIF and EndoG by modulating the Bcl- 2 family and MAPK/Akt signaling pathways.

Fatty acid synthesis (FASN) is an enzyme responsible for the de novo synthesis of long-chain fatty acids. During oncogenesis, FASN plays a role in growth and survival rather than acting within the energy storage pathways. Here, the function of FASN during early embryonic development was studied using its specific inhibitor C75. We found that the presence of the inhibitor reduced blastocyst hatching. FASN inhibition decreased Cpt1 expression, leading to a reduction in mitochondrial copy numbers and ATP content. This inhibition of FASN results in the down-regulation of the AKT pathway, thereby triggering apoptosis through the activation of the p53 pathway. Activation of the apoptotic pathways also leads to increased accumulation reactive oxygen species and autophagy. In addition, the FASN inhibitor can impair cell proliferation, a parameter of blastocyst quality for outgrowth. The level of OCT4, an important factor in embryonic development, decreased after treatment with the FASN inhibitor. These results show that FASN exerts an effect on the early embryonic development by regulation of both fatty acid oxidation and the AKT pathway in pigs.

Cancer cells are often found in an ischemic condition due to the rapid outgrowth of their vascular supply, and these cells are expected to develop an increased potential for local invasive growth. Since the first steps are characterized by increased motility and invasiveness, expression of molecules involved in cellular adhesion to extracellular matrix (ECM) is increased in the process of cancer cell invasion and metastasis. In this work we explored the molecular characteristics and its regulatory mechanism of hypoxic oral squamous cell carcinoma (OSCC) cells. Our experiment identified that hypoxia increases α5 integrin protein levels through phosphoinositide 3-kinase (PI3K)/Akt pathway in OSCC cells.

Akt, a serine/threonine protein kinase as a viral oncogene, is a critical regulator of PI3K-mediated cell proliferation and survival. On translocation, Akt is phosphorylated and activated, ultimately resulting in stimulation of cell growth and survival. As a part of our program toward the novel Akt1 inhibitors with potent activity over PI3K signaling pathway, we found primary hit compound 2 with an IC50 value of 620μM from protein kinase focused library. Based on the structural features of 2, new 1,3,4-thiadiazole derivatives were designed by the introduction of aromatic and heteroaromatic moieties onto thiadiazole nucleus. In this work, a series of 1,3,4-thiadiazole derivatives 1a-1 were synthesized and evaluated for Akt1 inhibitory activity.

Cordyceps militarisis well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militarisextract(CME) in human breast cancer MDA-MB-231 cells. It was found that CME treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNAcontent. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CME treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor,demonstrating the important role of caspase-3 in the observed cytotoxic effect. Cotreatment of CME and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CME in human breast cancer MDAMB- 231 through downregulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

The major component of green tea is (-)-epigallocatechin-3-gallate(EGCG) which accounts for 5080% of catechin, representing 200300 mg in a brewed cup of green tea. EGCG has been known to possess growth inhibitory and pro-apoptotic effect on human cancer cell lines such as prostate, bladder and breast cancers. In contrast, several studies have suggested that EGCG could promote cell proliferation and/or survival instead of pro-apoptotic effect. Understanding how intracellular signaling pathways respond to EGCG may provide a clue to the difference of cell responses and basis for usefulness of EGCG as a chemopreventive and/or chemotherapeutic agent. To better understand the mechanisms responsible for the chemopreventive efficacy of EGCG, the authors tried to identify the key molecules that contributes to Akt activation and can inhibit this activation. In the present study, EGCG increased Akt phosphorylation, an activeform of Akt and negatively affect on direct upstream molecules of Akt including PTEN and EGFR, though Akt phosphorylation was increased.

( - ) -epigall ocatechin - 3 -ga ll ate(EGCG) 는 녹차에서 추출되는 주된 성분으로 항산화. 세포 증식 억제 및 세 포 자멸사를 유도힌다 고 알려져 있다‘ 현 재 끼지의 여러 연구에 의하띤 EGCG는 세 포 성장을 억제하고 나아가서는 apoptoS1S까지도 유발한다. 한편 일부 연구는 EGCG가 오히려 apo ptosi s를 억 제 하고， 세 포 증식을 촉진한다고 보고하고 있다. 저자들은 EGCG가 이러한 상반된 효과틀을 보이게 되 는 기전과 그에 관련된 물질들을 파악하고지 하였다， EGCG를 세포에 처리시 초기에는 세포 생존에 관여힌다고 알려진 인 산화된 Akt 단백이 증가함이 관찰되었다 그 외에도 인산화된 Erk 단백 등의 증가로 EGCG가 세포 생존을 지속시키 는 역할을 하고 있음을 알 수 있었다‘ 이러한 현상은 COS7 과 A549 세 포 에서 관찰되었으며 Hela 세포에서는 관찰되지 않아 세 포외부에서 EGCG가 결합하게 되 는 물질 혹은 세 포내 물질 등의 차이에 의해 세 포 미다 EGCG에 대한 반응이 다른 것으로 추측된다 24시간 이상 처리된 경우 ECCG가 세 포 생존에 관린된 인자들을 감소시키는 것으로 보아 EGCG에 처음에는 세 포 생존을 유도하지만 장시간 처리 시 세 포 증식 및 생존을 억제하는 물질 임 을 확인하였다.

Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

In t his study, we tried to identify the key elements that respond to EGCG t reatment and its role in cell survival 0 1' apop tosis by EGCG. focusing on Akt pathway and Raf-MEK-ERK pathways. Cells were serum starved for 16 h and then treated with (-) -epiga llocatechin-3-gallate. To cletermine which pathway is related to effects of EGCG on cell s, the levels of phosphorylated Akt(pAkt) and Erk (pErk) were a nalyzed by immunoblotting. A549 cell s showed the increase of pAkt in response to EGCG‘ whereas Hela cells exhi bited no difference in the levels of pAkt by EGCG treatment Phos phorylation of Akt over initial basal levels became evident a fter 1 h of EGCG treatment and peaked at 3 h pErk was also increased by EGCG in Hela cells as well as in A549 cells To determine th e effect of EGCG on growth of cells‘ A549 cells were treated wi th vari 。u s concentrations of EGCG (from 10 μ M to 300 μ M) for 3 h. Cell growth was examined by MTI assay. The resulting growth curves of A549 cell s showed that EGCG promotecl cell prolifera tion in a close-dependent manner at early phase. When cells were t rea ted with EGCG for 24 h. pAkt and pErk expressions were significantly i띠1ibited ， even at 10 μ M B-raf ex pression was also clecreased in a close-dependent manner. In teresti ngly. the presence of serum weakened t his inhibitory effect of EGCG on the ex pression of survival facto rs. Our study inrucates that EGCG stimulates cell survival of A549 cells through thc PI3K/AKT pathway. though it fina lly be haves like a suppressive agent on cell su rvival

Cordyceps militaris is well known as a traditional herbal ingredient, which has been used for patients suffering from cancer in oriental medicine. In this study we have investigated the biochemical mechanisms of anti-proliferative effects by C. militaris extract(CBE) in human breast cancer MDA-MB-231 cells. It was found that CBE treatment induced chromatin condensation, mitochondrial energization, annexin V staining and sub-G1 phase DNA content. These indicators of apoptosis correlate with the mitochondrial dependent pathway, which results in the activation of caspase-3 activity. Both the cytotoxic effect by CBE treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, demonstrating the important role of caspase-3 in the observed cytotoxic effect. Co-treatment of CBE and LY294002, resulted in significantly induction of apoptosis. These results indicate that caspase-3 is a key regulator of apoptosis in response to CBE in human breast cancer MDA-MB-231 through down regulation of Akt, and that the C. militaris extract may therefore have therapeutic potential against human breast cancer.

Epithelial-mesenchymal transition(EMT) plays a pivotal role in the convers ion of earl y s tage tumors into invasive malignancies‘ and has been shown to be regulated hy the transcri ptional factor. Snail. Recent ly‘ actlvatlon of the phosphatidylinositol 3' kinase (PI3K)/따<:T axis is emerging as a centra l feature of EMT‘ However. it is unclear whether the phosphorylation of AKT regulate the expl'ession of s nail in ora l cancer cell underwent EMT. T。 investigate a role of p-AKT in EMT, we assessed the effects of inhibi ting p-AK1' activity in oral squamous can cer cells(KOSCC-25B) using PIAs, structurally modified phosphatidyli nositol ether lipid analogues(P1As) . PIAs de creased phosphorylation of c-Jun N-terrninal Kinase(JNK) and increased phosphorylation of glycogen synthase kinase 3beta(GSK-3beta). Inhibition of p-AKT ir빼ce d down regulation of Snail and Twist. but Sip1 regulated independent of p-AKT inhibition. Also inhibi tion of p-AKT dec reased cell migration and invas ion. Therefore our results implicate that p-AKT may contribute to the translocalization of sna il in the EMT associated with canceJ cell rnigration and invasion

Apoptos is s ignal- regulating kinase 1 (ASKl) is a rnitogen-activated protein kinase kinase kinase(MAP3K) 떼 th proapoptotic functlOn 1'he kinase activity of ASKl is stimulated by a variety of death signals , including 1'NFα • Fas ligation, reactive oxygen species, and antineoplastic agents, ASKl promotes cell death by activating the c- Jun N-termina l kinase/stress-activated protein kinase MKK4/MKK7-JNK/SAPK pathway and MKK3/ 1\αCK6-p38 pathway‘ ASKl activity is highly controlled in cells by multiple mechanisms, including phosphorylation, oligome ri zation, and protein- protein ll1 teractlOns Epigallocatechin-3-galla te(EGCG) is the major bioactive polyphenol present in green tea, It possesses anti-oxida nt , a nti - mutagenic‘ a n ti - prote이 ytic ， and anti-proliferative activity, In addition. it has been shown to inhibit cyclin activity, and inhibit cell cycle progression 1n the present study, we exarnined the effect of EGCG on ASKl- overexpressed cells , We expected that EGCG contributes to cell a poptos is by activating ASKl functlOn However, EGCG showed no suppressive effect on cell s urvival of ASKl-overexpressed cells and seemed to promote cell survlval Importantly, the EGCG treatment in creased Akt activity when cells expressed enough amount of ASKl protein, These results s uggest that the presence of ASKl may modify the inhibitory effect of EGCG on cell survival through Akt pathway,