S-phase cell cycle arrest, apoptosis, and molecular mechanisms of aplasia ras homolog member I-induced human ovarian cancer SKOV3 cell lines

Preliminary evaluation of antiproliferative and apoptotic activities of novel indolin-2-one derivatives

Indole-based agents are frequently used in targeted or supportive therapy of several cancers. In this study, we investigated the anticancer properties of originally synthesized novel indolin-2-one derivatives (6a-d) against Malignant Mesothelioma, Breast cancer, and Colon Cancer cells. Our results revealed that all derivatives were effectively delayed cell proliferation by inhibiting the ERK1/2, AKT, and STAT3 signaling pathways in a concentration-dependent manner. Additionally, these variants induced cell cycle arrest in the S phase, accompanied by elevated levels of p21 and p27 expressions. Derivatives also initiated mitochondrial apoptosis through the upregulation of Bax and downregulation of Bcl-2 proteins, leading to the activation of caspase 3 and PARP cleavage in exposed cells. Remarkably, three of the indolin-2-one derivatives displayed significant selectivity towards Breast and Colon Cancer cells, with compound 6d promising as the most potent and wide spectral one for all cancer cell lines.

Pendimethalin exposure induces bovine mammary epithelial cell death through excessive ROS production and alterations in the PI3K and MAPK signaling pathways

Herbicides are chemicals that have been established to have adverse impacts. However, they are still widely used in agriculture. Pendimethalin (PDM) is an herbicide that is widely used in many countries to control annual grasses. The possibility of livestock being exposed to PDM is relatively high, considering the half-life of PDM and its residues in water, soil and crops. However, the toxicity of PDM in cattle, especially in the mammary glands, has not been reported. Therefore, we investigated whether PDM has toxic effects in the mammary epithelial cells (MAC-T) of cattle. MAC-T cells were treated with various doses (0, 2.5, 5 and 10 μM) of PDM. We found that PDM affected cell viability and cell proliferation and causes cell cycle arrest. Furthermore, PDM triggered cell apoptosis, induced excessive ROS production and mitochondrial membrane potential (MMP) loss, and disrupted calcium homeostasis. In addition, PDM altered the activation of proteins associated with the endoplasmic reticulum (ER) stress response and modified PI3K and MAPK signaling cascades. In conclusion, our current study unveiled the mechanism of PDM in MAC-T cells and we suggest that PDM might be harmful to the mammary gland system of cattle, possibly affecting milk production.

Hitting Multiple Cellular Targets in Triple-Negative Breast Cancer Using Dual-Action Cisplatin(IV) Prodrugs for Safer Synergistic Chemotherapy

Triple-negative breast cancer (TNBC) cells show improved sensitivity for cisplatin therapy due to their defective DNA damage repair system. However, the clinical utilization of cisplatin is limited by dose-dependent systemic toxicities and chemoresistance. Cisplatin Pt(IV) derivatives having kinetically inert octahedral geometry provide an effective strategy to overcome these limitations. Upon cellular reduction, these derivatives release cisplatin and axial ligands, acting as dual-action prodrugs. Hereby, we have developed three cisplatin(IV) conjugates using distinct bioactive axial moieties (valproate, tocopherol, and chlorambucil), which can synergistically complement cisplatin activity and attack multiple cellular targets. The designed derivatives showcased enhanced antiproliferative activity and improved therapeutic synergism along with a noteworthy cisplatin dose reduction index in a panel of six cancer cells. These Pt(IV) derivatives remarkably improved cellular drug uptake and showed lower dependency on copper transporter 1 (Ctr1) for uptake than cisplatin. The results of enhanced in vitro activity were well corroborated by in vivo efficacy testing in the 4T1 cell-based TNBC model, showcasing ∼2-7-folds higher tumor volume reduction for Pt(IV) derivatives than cisplatin. In addition, the designed derivatives significantly reduced the nephrotoxicity risk involved in cisplatin therapy, indicated by systemic toxicity biomarkers and organ histopathology. The results indicated that cisplatin(IV) derivatives could open new avenues for safer synergistic chemotherapy in TNBC.

S-Adenosylmethionine affects ERK1/2 and STAT3 pathway in androgen-independent prostate cancer cells

Background

The most critical point in the treatment of prostate cancer is the progression towards a hormone-refractory tumour, making research on alternative therapies necessary. This study focused on the methyl donor S-adenosylmethionine (SAM), which is known to act as an antitumourigenic in several cancer cell lines. Though a genome-wide downregulation of proto-oncogenes in prostate cancer cell lines treated with SAM is obvious, the anticancer effects remain elusive. Thus, in this study, the impact of SAM treatment on the cell cycle, apoptosis and cancer-related pathways was investigated.

Methods and results

After performing SAM treatment on prostate cancer cell lines (PC-3 and DU145), a cell-cycle arrest during the S-phase, a downregulation of cyclin A protein levels and an upregulation of p21 cell cycle inhibitor were observed. The proapoptotic Bax/Bcl-2 ratio and the caspase-3 activity were elevated; additionally, the apoptosis rate of SAM treated cells increased significantly in a time-dependent manner. Moreover, immunoblots displayed a downregulation of Erk1/2 and STAT3 phosphorylation accompanied by a reduced expression of the STAT3 protein.

Conclusion

SAM caused changes in cancer-related pathways, probably leading to the effects on the cell cycle and apoptosis rate. These results provide deeper insights into the anticancer effects of SAM on prostate cancer cells.

Loss of TIPE3 reduced the proliferation, survival and migration of lung cancer cells through inactivation of Akt/mTOR, NF-κB, STAT-3 signaling cascade

Lung cancer is the foremost cause of cancer related mortality among men and one of the most fatal cancers among women. Notably, the 5-year survival rate of lung cancer is very less; 5% in developing countries. This low survival rate can be attributed to factors like late stage diagnosis, rapid postoperative recurrences in the patients undergoing treatment and development of chemoresistance against different agents used for treating lung cancer. Therefore, in this study we evaluated the potential of a recently identified protein namely TIPE3 which is known as a transfer protein of lipid second messengers as a lung cancer biomarker. TIPE3 was found to be significantly upregulated in lung cancer tissues indicating its role in the positive regulation of lung cancer. Supporting this finding, knockout of TIPE3 was also found to reduce the proliferation, survival and migration of lung cancer cells and arrested the G2 phase of cell cycle through inactivation of Akt/mTOR, NF-κB, STAT-3 signaling. It is well evinced that tobacco is the major risk factor of lung cancer which affects both males and females. Therefore, this study also evaluated the involvement of TIPE3 in tobacco mediated lung carcinogenesis. Notably, this study shows for the first time that TIPE3 positively regulates tobacco induced proliferation, survival and migration of lung cancer through modulation of Akt/mTOR signaling. Thus, TIPE3 plays critical role in the pathogenesis of lung cancer and hence it can be specifically targeted to develop novel therapeutic strategies.

DIRAS3: An Imprinted Tumor Suppressor Gene that Regulates RAS and PI3K-driven Cancer Growth, Motility, Autophagy, and Tumor Dormancy

DIRAS3 is an imprinted tumor suppressor gene that encodes a 26 kDa GTPase with 60% amino acid homology to RAS, but with a distinctive 34 amino acid N-terminal extension required to block RAS function. DIRAS3 is maternally imprinted and expressed only from the paternal allele in normal cells. Loss of expression can occur in a single "hit" through multiple mechanisms. Downregulation of DIRAS3 occurs in cancers of the ovary, breast, lung, prostate, colon, brain, and thyroid. Reexpression of DIRAS3 inhibits signaling through PI3 kinase/AKT, JAK/STAT, and RAS/MAPK, blocking malignant transformation, inhibiting cancer cell growth and motility, and preventing angiogenesis. DIRAS3 is a unique endogenous RAS inhibitor that binds directly to RAS, disrupting RAS dimers and clusters, and preventing RAS-induced transformation. DIRAS3 is essential for autophagy and triggers this process through multiple mechanisms. Reexpression of DIRAS3 induces dormancy in a nu/nu mouse xenograft model of ovarian cancer, inhibiting cancer cell growth and angiogenesis. DIRAS3-mediated induction of autophagy facilitates the survival of dormant cancer cells in a nutrient-poor environment. DIRAS3 expression in dormant, drug-resistant autophagic cancer cells can serve as a biomarker and as a target for novel therapy to eliminate the residual disease that remains after conventional therapy.

Attenuation of tacrolimus induced oxidative stress, mitochondrial damage, and cell cycle arrest by Boerhavia diffusa root fraction in mdck cell lines

OBJECTIVES

The protective effect of ethyl acetate fraction (EAF) of Boerhavia diffusa roots against Tacrolimus (TAC) induced nephrotoxicity was studied using MDCK cell lines.

MATERIALS AND METHODS

Ethanolic root extract of B. diffusa was fractionated using the liquid-liquid partition method. The cytotoxic effect of TAC and protective effect of EAF co-treatment were studied in MDCK cell lines by measuring ROS, LPO, and NO levels; collagen accumulation, effect on mitochondrial membrane integrity and cell cycle analysis were studied. The active component in EAF was quantified by HPLC analysis.

RESULTS

TAC induced toxicity, leading to apoptosis and necrosis, was significantly reduced (P<0.001) in EAF co-treatment, with reversal of cell cycle arrest and reduced cell population at sub G0/G1 phase. Further, ROS (P<0.05), LPO and NO (P<0.001), were significantly reduced with EAF co-treatment compared with TAC individually treated cells. TAC induced mitochondrial membrane integrity loss was found to be significantly reduced in co-treated cells, as measured by rhodamine123 (P<0.05) and translocation of cytochrome c (P<0.001) from nucleus to cytoplasm, and caspase 3 release (P<0.001). The same was confirmed through annexin-FITC and PI staining (P<0.05) with reduced apoptotic and necrotic death in co-treated population. Interestingly, EAF co-treatment decreased collagen accumulation (P<0.001) with significant increase in the cell survival of tubular epithelial cells. HPLC analysis showed the presence of Quercetin (87.5 mg/g) in EAF, which may be responsible for the nephroprotective role.

CONCLUSION

Thus, these results provide sound evidence that EAF may be an effective adjuvant therapy to prevent nephrotoxicity induced by TAC.

TIPE2 Induced the Proliferation, Survival, and Migration of Lung Cancer Cells Through Modulation of Akt/mTOR/NF-κB Signaling Cascade

Lung cancer represents the most common cause of cancer deaths in the world, constituting around 11.6% of all new cancer cases and 18.4% of cancer-related deaths. The propensity for early spread, lack of suitable biomarkers for early diagnosis, as well as prognosis and ineffective existing therapies, contribute to the poor survival rate of lung cancer. Therefore, there is an urgent need to develop novel biomarkers for early diagnosis and prognosis which in turn can facilitate newer therapeutic avenues for the management of this aggressive neoplasm. TIPE2 (tumor necrosis factor-α-induced protein 8-like 2), a recently identified cytoplasmic protein, possesses enormous potential in this regard. Immunohistochemical analysis showed that TIPE2 was significantly upregulated in different stages and grades of lung cancer tissues compared to normal lung tissues, implying its involvement in the positive regulation of lung cancer. Further, knockout of TIPE2 resulted in significantly reduced proliferation, survival, and migration of human lung cancer cells through modulation of the Akt/mTOR/NF-κB signaling axis. In addition, knockout of TIPE2 also caused arrest in the S phase of the cell cycle of lung cancer cells. As tobacco is the most predominant risk factor for lung cancer, we therefore evaluated the effect of TIPE2 in tobacco-mediated lung carcinogenesis as well. Our results showed that TIPE2 was involved in nicotine-, nicotine-derived nitrosamine ketone (NNK)-, N-nitrosonornicotine (NNN)-, and benzo[a]pyrene (BaP)-mediated lung cancer through inhibited proliferation, survival, and migration via modulation of nuclear factor kappa B (NF-κB)- and NF-κB-regulated gene products, which are involved in the regulation of diverse processes in lung cancer cells. Taken together, TIPE2 possesses an important role in the development and progression of lung cancer, particularly in tobacco-promoted lung cancer, and hence, specific targeting of it holds an enormous prospect in newer therapeutic interventions in lung cancer. However, these findings need to be validated in the in vivo and clinical settings to fully establish the diagnostic and prognostic importance of TIPE2 against lung cancer.

Acidic pH derived from cancer cells as a double-edged knife modulates wound healing through DNA repair genes and autophagy

Wound healing is a sequester program that involves diverse cell signalling cascades. Notwithstanding, complete signal transduction pathways underpinning acidic milieu derived from cancer cells is not clear, yet. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, fluorescein diacetate/propidium iodide staining, and cell cycle flow cytometry revealed that acidic media decreased cell viability and cell number along with enhanced dead cells and S-phase arrest in normal fibroblasts. Notably, the trends of intracellular reactive oxygen species production and lactate dehydrogenase release significantly increased with time. It seems the downregulation of Klf4 is in part due to acidosis-induced DNA damage. It promoted cells towards S-phase arrest and diminished cell proliferation. Klf4 downregulation had a direct correlation with the P53 level while acidic microenvironment promotes cells towards cell death mechanisms including apoptosis and autophagy. Noteworthily, the unchanged levels of Rb and Mlh1 indicated in those genes had no dominant role in the repairing of DNA damage in fibroblasts treated with the acidic microenvironment. Therefore, cells owing to not entering to mitosis and accumulation of DNA damage were undergone cell death to preserve cell homeostasis. Since acidic media decreased the level of tumour suppressor and DNA repair genes and altered the normal survival pathways in fibroblasts, caution should be exercised to not lead to cancer rather than wound healing.

Comparison of the effect of rhodium citrate-associated iron oxide nanoparticles on metastatic and non-metastatic breast cancer cells

Background

Nanocarriers have the potential to improve the therapeutic index of currently available drugs by increasing drug efficacy, lowering drug toxicity and achieving steady-state therapeutic levels of drugs over an extended period. The association of maghemite nanoparticles (NPs) with rhodium citrate (forming the complex hereafter referred to as MRC) has the potential to increase the specificity of the cytotoxic action of the latter compound, since this nanocomposite can be guided or transported to a target by the use of an external magnetic field. However, the behavior of these nanoparticles for an extended time of exposure to breast cancer cells has not yet been explored, and nor has MRC cytotoxicity comparison in different cell lines been performed until now. In this work, the effects of MRC NPs on these cells were analyzed for up to 72 h of exposure, and we focused on comparing NPs’ therapeutic effectiveness in different cell lines to elect the most responsive model, while elucidating the underlying action mechanism.

Results

MRC complexes exhibited broad cytotoxicity on human tumor cells, mainly in the first 24 h. However, while MRC induced cytotoxicity in MDA-MB-231 in a time-dependent manner, progressively decreasing the required dose for significant reduction in cell viability at 48 and 72 h, MCF-7 appears to recover its viability after 48 h of exposure. The recovery of MCF-7 is possibly explained by a resistance mechanism mediated by PGP (P-glycoprotein) proteins, which increase in these cells after MRC treatment. Remaining viable tumor metastatic cells had the migration capacity reduced after treatment with MRC (24 h). Moreover, MRC treatment induced S phase arrest of the cell cycle.

Conclusion

MRC act at the nucleus, inhibiting DNA synthesis and proliferation and inducing cell death. These effects were verified in both tumor lines, but MDA-MB-231 cells seem to be more responsive to the effects of NPs. In addition, NPs may also disrupt the metastatic activity of remaining cells, by reducing their migratory capacity. Our results suggest that MRC nanoparticles are a promising nanomaterial that can provide a convenient route for tumor targeting and treatment, mainly in metastatic cells.

Normobaric hyperoxia inhibits the progression of lung cancer by inducing apoptosis

Hypoxia is a critical characteristic of solid tumors with respect to cancer cell survival, angiogenesis, and metastasis. Hyperoxic treatment has been attempted to reverse hypoxia by enhancing the amount of dissolved oxygen in the plasma. In this study, we evaluated the effects of normobaric hyperoxia on the progression of lung cancer to determine whether oxygen toxicity can be used in cancer therapy. Following a tail vein injection of the Lewis lung carcinoma cells, C57BL/6J mice were exposed to a 24-h normobaric hyperoxia/normoxia cycle for two weeks. In addition, A549 lung cancer cells were incubated in a normobaric hyperoxia chamber for a 24-h period. As a result, the size and number of tumors in the lung decreased significantly with exposure to normobaric hyperoxia in the mouse model. Cell viability, colony-forming ability, migration, and invasion all decreased significantly in A549 cells exposed to normobaric hyperoxia and the normal control group exposed to normobaric hyperoxia showed no significant damage. Oxidative stress was more prominent with exposure to normobaric hyperoxia in cancer cells. A549 cells exposed to normobaric hyperoxia showed a significantly higher cell apoptosis ratio compared with A549 cells without normobaric hyperoxia exposure and normal human lung cells (BEAS-2B cells). The Bax/Bcl-2 mRNA expression ratio also increased significantly. Changes in the key regulators of apoptosis were similar between in vivo and in vitro conditions. The p-ERK level decreased, while the p-JNK level increased, after normobaric hyperoxia exposure in A549 cells. This study demonstrated the role of normobaric hyperoxia in inhibiting lung cancer. Normal tissue and cells showed no significant hyperoxic damage in our experimental setting. The anti-tumor effect of normobaric hyperoxia may due to the increased reactive oxygen species activity and apoptosis, which is related to the mitogen-activated protein kinase pathway. Impact statement Normobaric hyperoxia (NBO) is a feasible therapy for cancer with a low complication rate. Although NBO may be beneficial in cancer treatment, very few studies have been conducted; thus, the evidence is thin. This is the first study to clearly demonstrate morphological changes in lung cancer with NBO exposure and to investigate the underlying mechanisms both in vivo and in vitro. This study will arouse interest in NBO treatment and promote further research.

A Novel Selective JAK2 Inhibitor Identified Using Pharmacological Interactions

The JAK2/STAT signaling pathway mediates cytokine receptor signals that are involved in cell growth, survival and homeostasis. JAK2 is a member of the Janus kinase (JAK) family and aberrant JAK2/STAT is involved with various diseases, making the pathway a therapeutic target. The similarity between the ATP binding site of protein kinases has made development of specific inhibitors difficult. Current JAK2 inhibitors are not selective and produce unwanted side effects. It is thought that increasing selectivity of kinase inhibitors may reduce the side effects seen with current treatment options. Thus, there is a great need for a selective JAK inhibitor. In this study, we identified a JAK2 specific inhibitor. We first identified key pharmacological interactions in the JAK2 binding site by analyzing known JAK2 inhibitors. Then, we performed structure-based virtual screening and filtered compounds based on their pharmacological interactions and identified compound NSC13626 as a potential JAK2 inhibitor. Results of enzymatic assays revealed that against a panel of kinases, compound NSC13626 is a JAK2 inhibitor and has high selectivity toward the JAK2 and JAK3 isozymes. Our cellular assays revealed that compound NSC13626 inhibits colorectal cancer cell (CRC) growth by downregulating phosphorylation of STAT3 and arresting the cell cycle in the S phase. Thus, we believe that compound NSC13626 has potential to be further optimized as a selective JAK2 drug.

The mechanisms of DIRAS family members in role of tumor suppressor

DIRAS family is a group of GTPases belonging to the RAS superfamily and shares homology with the pro-oncogenic Ras GTPases. Currently, accumulating evidence show that DIRAS family members could be identified as putative tumor suppressors in various cancers. The either lost or reduced expression of DIRAS proteins play an important role in cancer development, including cell growth, migration, apoptosis, autophagic cell death, and tumor dormancy. This review focuses on the latest research regarding the roles and mechanisms of the DIRAS family members in regulating Ras function, cancer development, assessing potential challenges, and providing insights into the possibility of targeting them for therapeutic use.

Effects of HAD-B1 on the proliferation of A549 cisplatin-resistant lung cancer cells

The present study investigated the toxicity of HangAmDan-B1 (HAD-B1) on A549-Cisplatin resistant (A549CR) cells. HAD‑B1 inhibited the growth of A549CR cells in a concentration‑dependent manner; HAD‑B1 was more effective at inhibiting A549CR cell viability compared with vehicle‑treated cells. The reduction in viability may be due to S‑phase cell cycle arrest and the induction of apoptosis in HAD‑B1‑treated cells. Cell cycle protein profile analysis of HAD‑B1‑treated A549CR cells using an InnoPharmaScreen (IPS) ProteoChip‑based antibody microarray chip indicated downregulation of signal transducer and activator of transcription 3. The activities of caspase‑3, ‑8 and ‑9 were significantly increased in HAD‑B1‑treated cells when compared with the vehicle‑treated control group. Furthermore, the HAD‑B1‑treated group exhibited similarly increased caspase levels when compared with the Afatinib‑treated group. Taken together, these observations suggest that HAD‑B1 may be a promising candidate for further research into the therapeutic management of cisplatin-resistant lung cancer.

Albumin coated cadmium nanoparticles as chemotherapeutic agent against MDA-MB 231 human breast cancer cell line

With the aim of dedicating toxicity of cadmium nanoparticles (CdNPs) against invasive breast cancer, with minimum damage to surrounding healthy cells, CdNPs were coated with albumin nanocarrier by nanoprecipitation method and named CdNPs@BSA. The characterization was done by TEM image, DLS and UV-Vis, fluorescence, circular dichroism spectroscopy. The cytotoxic efficacy of the CdNPs@BSA against human breast cancer cells (MDA-MB 231 cells) was examined by MTT assay. Apoptosis, as the mechanism of cell death, was verified by inverted microscopy, fluorescent microscopy, gel electrophoresis and flow cytometry. The role of ROS generation in apoptosis was also studied. It was found that the resulted CdNPs@BSA (diameter of 88 nm and zeta potential of about -18.85 mV) was suitable for penetration in tumour micro vessels. In the form of CdNPs@BSA, the 77% of the secondary structure and almost all of the tertiary structure remain intact. Comparing to CdNPs, CdNPs@BSA could significantly suppress the MDA-MB 231 while they were less toxic on WBCs. Therefore, they could be a brilliant candidate to be used as a chemotherapeutic agent against invasive breast cancer cells.

Ginsenoside 20(S)‑Rg3 inhibits the Warburg effect through STAT3 pathways in ovarian cancer cells

Cancer cells prefer to metabolize glucose through aerobic glycolysis, known as the Warburg effect. It plays a crucial role in proliferation and progression of cancer cells. However, the complete mechanism remains elusive. In recent studies, the signal transducer and activator of transcription 3 (STAT3) signaling has been discovered to have roles in cancer‑associated changes in metabolism. In this study, we find that the ginsenoside 20(S)‑Rg3, a pharmacologically active component of the traditional Chinese herb Panax ginseng, inhibits glycolysis in ovarian cancer cells by regulating hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). We also show that 20(S)‑Rg3 regulates HK2 through downregulation of p‑STAT3 (Tyr705). Furthermore, overexpression of STAT3 in ovarian cancer cells weakened the suppression of Warburg effect induced by 20(S)‑Rg3. Importantly, 20(S)‑Rg3 treatment represses HK2 expression in nude mouse xenograft models of ovarian cancer. Taken together, our results show that 20(S)‑Rg3 inhibits the Warburg effect by targeting STAT3/HK2 pathway in ovarian cancer cells, highlighting the potentiality of 20(S)‑Rg3 to be used as a therapeutic agent for ovarian cancer.