Reduced expression ofβ-catenin inhibitor Chibby in colon carcinoma cell lines

AIM： To analyse the Chibby expression and its function in colon carcinoma cell lines and colorectal carcinoma （CRC）. METHODS： Chibby expression levels were investigated by quantitative RT-PCR in a panel of seven different colon carcinoma cell lines. By sequencing, we analysed mutational status of Chibby. To test whether Chibby exhibited effects on β-catenin signalling in colon carcinoma cells, we transfected SW480 cells with Chibby expression plasmid and, subsequently, analysed activity of β-catenin and tested for alterations in cellular phenotype. In addition, we examined Chibby mRNA levels in samples of colorectal carcinomas and adjacent normal tissues by using quantitative RT-PCR and hybridised gene chips with samples from CRC and normal tissues. RESULTS： Chibby mRNA expression was strongly downregulated in colon carcinoma cell lines in comparison to normal colon epithelial cells and no mutation in any of the examined colon carcinoma cell lines was found. Further, we could show that Chibby inhibited β-catenin activity in TOPflash assays when over-expressed in SW480 cells. Proliferation and invasion assays with Chibby transfected SW480 cells did not reveal profound differences compared to control cells. In contrast to these in vitro data, quantitative RT-PCR analyses of Chibby mRNA levels in CRC tumor samples did not show significant differences to specimens in adjacent non-cancerous tissue. Consistent with these findings, gene chips analysing tissue samples of tumors and corresponding normal tissue did not show altered Chibby expressionCONCLUSION： Altered Chibby expression might be observed in vitro in different colon carcinoma cell lines. However, this finding could not be confirmed in vitro in CRC tumors, indicating that Chibby is not likely to promote CRC tumor development or progression. As Chibby is an important inhibitor of β-catenin signalling, our data implicate that the usability of colon carcinoma cell lines for in vitro studies analysing the Wnt/β-catenin pathway in colorectal carcinoma needs extensive verification.

Effects of Meloxicam on Vascular Endothelial Growth Factor and Angiopoietin-2 Expression in Colon Carcinoma Cell Line HT-29

To investigate the effect of meloxicam, a selected NSAIDs, on cell growth, expression of VEGF and angiopointin-2 （Ang-2） protein in HT-29 cell line, cultured HT-29 cells were treated with meloxicam of various concentrations for various lengths of time. The proliferation of HT-29 was detected by cell counting kit-8 （CCK-8）, the cell cycle was determined by flow cytometer and the levels of VEGF and Ang-2 protein in supernatants were examined by enzyme linked immunosorbent assay （ELISA）. The mRNA expressions of VEGF and Ang-2 in cultured HT-29 were determined by real-time quantitative reverse-transcription polymerase chain reaction. Our results showed that treatment of meloxicam of different concentrations and for various lengths of time had a cytotoxicic effect on the cell proliferation of HT-29 cells in a concentration-dependant and time-dependant manner. Cell cycle analysis showed that the cells were mainly blocked in G0/G1 phase. The VEGF and Ang-2 protein levels in supernatants of the culture medium were decreased gradually in a concentration-dependent or time-dependent fashion. The mRNA expression of cox-2, VEGF and Ang-2 showed a gradual and concentration-dependent reduction. It is concluded that meloxicam can reduce the expression of VEGF and Ang-2 at the protein and mRNA level in colon carcinoma cell line.

STUDY ON THE EXPRESSION OF CYCLOOXYGENASE-2 IN HEPATOCELLULAR CARCINOMA CELL LINES AND ON THE GROWTH INHIBITION EFFECT OF NS-398

Objective： To investigate the expression of cyclooxygenase -2 （COX-2） in hepatocellular carcinoma cell lines and to explore the effect of NS-398, a selective inhibitor for COX-2, on HepG-2 cell line. Methods： lmmunohistochemistry and RT-PCR were used to investigate COX-2 expression in 6 HCC cell lines. MTT and Flowcytometry were used to evaluate the effect of the selective inhibitor of COX-2, NS-398, on HepG-2 cell lines. Results： All six HCC cell lines showed COX-2 expression at protein level. Five out of 6 cell lines showed COX-2 expression at mRNA level. NS-398 could suppress the growth of HepG-2 cell line, in a time and dose dependant manner. Conclusion： NS-398, a selective inhibitor of COX-2, showed inhibition effect on HepG-2 HCC cell line. The efficacy of inhibition was time and dose dependent, providing a new evidence for chemoprovention of hepatocellular carcinorma with COX-2 selective inhibitors.

Induced Differentiation of Epithelioid Carcinoma Cell Lines: Evidence for Tumor Cell Quantal Mitosis

The effects of growth factors and calcium concentrations present in different culture media on induction of terminal differentiation were investigated for four different epidermoid carcinoma cell lines, Hela, KB, A431, and SCC-25, and their responses determined relative to those elicited by normal human keratinocytes subjected to these culture conditions. Differentiation status was determined cyto-chemically by a validated keratin protein staining method, and by autoradiographic analyses. Growth and differentiation promoting factors that influenced the direction of integrated control of growth and differentiation in normal human keratinocytes were found to be effective for some cell lines but not others. The factors examined were 1) high density arrest in serum-free and serum-containing media, 2) media shifts from high density culture in serum-containing media to low density growth factor-depleted or supplemented serum-free medium, and 3) the concentration of calcium in the media. The extent and degree of differentiation achieved varied among different cell lines depend on the presence or absence of serum, EGF and insulin protein growth factors. Certain growth media appear to sponsor keratin protein, cyto-chemically-detected differentiation, and evidence of quantal mitotic division in low density HeLa cell and SCC25 cell cultures. Epidermoid carcinoma cell lines retain limited capacity to commit to early stages of cell differentiation.

Modulating effects of survivin antisense oligonucleotide on changes of apoptosis and cell cycle of human hepatocellular carcinoma cell line SMMC-7721

To investigate the modulating effects of survivn antisense oligonucletode (ASODN) on the cell cycle and apoptosis of human hepatocellular carcinoma (HCC) cell line SMMC-7721 and explore its mechanism.Methods Survivin ASODN was transfected into SMMC-7721 cells mediated by DOTAP liposomal reagent.Electron microscopy,flow cytometry and RT-PCR were used to detect the changes in cell ultrastructure,apoptosis,cell cycle and the expression of cyclinB1 mRNA,respectively.Results After transfection of survivin ASODN,the expression of cyclinB1 mRNA in the cells significantly increased and increase in G2-M arrest and apoptosis appeared.Meanwhile,the cell ultrastructure had apoptotic changes such as chromatin condensation and apoptotic body formation.Conclusion Survivin ASODN can induce the expression of cyclinB1 that may result in G2-M arrest.Consequently,apoptosis is triggered.Survivin ASODN transfection might be an improtant new treatment for HCC.14 refs,2 figs,1 tab.

Potential roles of EZH2, Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma cell line Hep3B

AIM: To investigate the potential roles of enhancer of zeste homolog2(EZH2), Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma(HCC) cell line Hep3 B.METHODS: A total of 73 patients who underwent surgical resection at Fuzong Clinical Medical College of Fujian Medical University were enrolled in this study. Hep3 B cells were cultivated in RPMI 1640 medium supplemented with 10% fetal bovine serum at 37?℃. Vectors that containing c DNA of the EZH2 gene or mi R-203 targeted sh RNA plasmid were constructed, and then transfected into Hep3 B cells. The m RNA expression of mi R-203, EZH2, and Bmi-1 was analyzed using quantitative real-time polymerase chain reaction analysis, and the protein levels of EZH2 and Bmi-1 were detected by Western blot analysis. Effect of EZH2 or mi R-203 on cell proliferation was observed by methyl thiazolyl tetrazolium assay, and cell apoptosis was assessed using flow cytometry. Besides, effect of EZH2 or mi R-203 on tumor cell invasion was detected using Transwell assay.RESULTS: The m RNA levels of EZH2 and Bmi-1 in HCC tissues and in Hep3 B cells were significantly higher compared with those in normal samples(P < 0.01), while mi R-203 level was significantly lower in HCC tissues(P < 0.01). Hep3 B cells transfected with EZH2-sh RNA or mi R-203-sh RNA showed lower expression levels of EZH2 and Bmi-1(P < 0.05). Compared with controls, Hep3 B cells transfected with EZH2-sh RNA had relative slow cell proliferation, indicating that low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could inhibit Hep3 B cell proliferation(P < 0.05). The average apoptosis rate of Hep3 B cells transfected with EZH2-sh RNA vector was about 18.631%, while that of Hep3 B cells transfected with sh RNA vector was about 5.33%, suggesting that EZH2 was down-regulated by transfecting with EZH2-sh RNA, and the down-regulated EZH2 contributed to the cell apoptosis. Low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could reduce Hep3 B cell invasion(P < 0.05).CONCLUSION: Our study suggests that EZH2 and Bmi-1 are up-regulated while mi R-203 is downregulated in Hep3 B cells. Mi R-203 may contribute to the metastasis and enhance apoptosis of HCC cells by regulating EZH2 and Bmi-1. Our study may provide a theoretical basis for metastasis of HCC and targeted therapy of HCC.

Up-Regulation of the Gap Junction Intercellular Communication by Tea Polyphenol in the Human Metastatie Lung Carcinoma Cell Line

Our previous study has proven that tea polyphenol has a role in lung neoplasms. The present communication was to investage the anti-proliferation effect of tea polyphenol on the PG cells, which was a high metastatic human lung carcinoma cell line, by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) cell viability assay, and to study the change of intracellular calcium concentration, connexin43 (Cx43) expression, gap junctional intercellular communication (GJIC) and cell cycle distribution after the tea polyphenol treatment by laser scanning confocal microscopy and flow cytometry. The results showed that 1) tea polyphenol could kill the PG cells in a dose-depent manner via inhibiting the PG cell proliferation and blocking the PG cell cycle progression staying in G0/G1 phase and not transfering in S and G2/M phases to reduce the PG cell proliferation index;2) the increases of intracellular calcium concentration, GJIC and Cx43 expression were related with the tea polyphenol doses. The data suggested that tea polyphenol could inhibit the growth of PG cells, which mechanism was associated with the up-regulation of GJIC.

MiR-25-3p attenuates the proliferation of tongue squamous cell carcinoma cell line Tca8113

Objective:To investigate the effects of miR-25-3p on the occurrence,development and proliferation of tongue squamous cell carcinoma cells.Methods:To establish tongue squamous cell carcinoma cell line Tca8113 that stably and highly express miR-25-3p using recombinant reiroviral vector-mediated gene transfer method.The proliferation of transfected Tca8113 was detected by thiazolyl blue tetrazolium bromide(MTT)and cell colony formation assays.eyclnD1,p21^(cipt)and p27^(kipt)mRNA expressions in the transfected Tca-8113 were detected by quantitative PCR.cyclinD1,p21^(cipt),p27^(kipt),AKT,p-AKT,FOXOt and p-FOX01 expressions in the transfected Tca8113 were detected by western blot analysis.In addition,miR-25-3p expression in the tongue squamous cell carcinoma cell line and tissue specimen was also detected by quantitative PCR.Results:Quantitative PCR showed that mitt-25-3p expression in the tongue squamous cell carcinoma cell lines and tissue specimen was significantly lower than that in the adjacent tissue.MTT and cell colony formation assays showed that after miR-25-3p overexpression,the proliferation of transfected Tca8113 was obviously attenuated.Western blot analysis and quantitative PCR showed that after miR-25-3p overexpression.p21^(cipt)and p27^(kipt)expressions were upregulated,while cyclinD1,AKT,FOXO1 expressions were downregulated,and AKT and FOXO1 phosphorylation was inactivated in the transfected Tca8113 cells.Conclusions:MiR-25-3p inhibited the proliferation of tongue squamous cell carcinoma cells and regulated cell cycle-related protein expression,playing an important role in the occurrence and development of squamous cell carcinoma of the tongue.

Protein Profile of Human Lung Squamous Carcinoma Cell Line NCI-H226

Objective To construct a database of human lung squamous carcinoma cell line NCI-H226 and to facilitate discovery of novel subtypes markers of lung cancer. Method Proteomic technique was used to analyze human lung squamous carcinoma cell line NCI-H226. The proteins of the NCI-H226 cells were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. Results The results showed that a good reproducibility of the 2-D gel pattern was attained. The position deviation of matched spots among three 2-D gels was 1.95±0.53 mm in the isoelectric focusing direction, and 1.73±0.45 mm in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis direction. One hundred and twenty-seven proteins, including enzymes, signal transduction proteins, structure proteins, transport proteins, etc. were characterized, of which, 29 identified proteins in NCI-H226 cells were reported for the first time to be involved in lung cancer carcinogenesis. Conclusion The information obtained from this study could provide some valuable clues for further study on the carcinogenetic mechanism of different types of lung cancer, and may help us to discover some potential subtype-specific biomarkers of lung cancer.

Tinospora crispa extract inhibits MMP-13 and migration of head and neck squamous cell carcinoma cell lines

Objective: To investigate the effect of Tinospora crispa(T. crispa) extract on matrix metalloproteinase 13(MMP-13) expression and cell migration. Methods: The cytotoxicity of T. crispa extract was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on head and neck squamous cell carcinoma(HNSCC) cell lines. The effect on expression of MMP-13 was analysed by RT-PCR and ELISA. The migration was assessed by wound healing assay. Results: MMP-13 m RNA was highly expressed in the metastatic human HNSCC cell lines, HN22 and HSC-3. T. crispa extract at a concentration of 100.0 μg/m L caused about 50% reduction of cell survival. T. crispa extract at a non-toxic concentration of 12.5, 25.0 and 50.0 μg/m L signii cantly suppressed MMP-13 m RNA expression and secreted MMP-13 in both HN22 and HSC-3. The expression of tissue inhibitors of metalloprotease by HSC-3 cells was attenuated by 25.0 and 50.0 μg/m L of T. crispa extract. Addition of the extract to cells in a wound healing assay showed inhibition of cell migration by HN22 cells. Conclusions: These data suggest that T. crispa could be considered as a potential therapeutic drug to prevent metastasis of HNSCC.

Mutations and altered expression of p16^(INK4a) in human pancreatic carcinoma cell lines with different potential of metastasis

Objective:To analyze the p16INK4a genomic alteration and expression status in 3 human pancreatic carcinoma cell lines with different potential of metastasis. Methods:Using PCR-SSCP, Dot-blot and immunohistochemistry, the p16INK4a genomic mutation and expression were analyzed on DNA, mRNA and protein levels in 3 human pancreatic carcinoma cell lines Patu8902, Patu8988 and SW1990, which had different potential of metastasis. Results: (1) On DNA level: there was no deletion of p16INK4a Exon Ⅰ in 3cell lines; p16INK4a Exon Ⅱ was only deleted in Patu8902 while no deletion in Patu8988 and SW1990. No insertion, microdeletion and point mutation were found in the 3 cell lines. (2) On RNA level: the expression of p16INK4a protein was negative in Patu8902, low expressed in SW1990, but highly expressed in Patu8988.(3) On protein level: P16 protein was strongly stained in Patu8988, much lower in SW1990, but not stained in Patu8902. Conclusion:The genomic type and expression of p16INK4a are quite different in 3 pancreatic carcinoma cell lines which have different potential of metastasis. It is suggested that genomic homozygous deletion and low expression of mRNA might relate to the potential of metastasis of pancreatic cell lines. In other words, dysfunction of p16INK4a might be an important mechanism in the metastasis of pancreatic carcinoma.

c-Ha-ras and c-myc antisense oligodeoxynucleotides inhibit the proliferation and DNA synthesis in human gastric carcinoma cell lines

The effects of two antisense oligodeoxynucleotides on the expression of c-Ha-ras proto-oncogene and the growth of human gastric carcinoma cell lines were observed. Synthetic 15-mer directed at the region of the translational initiation site of c-Ha-ras proto-oncogene (ASO-r) greatly inhibited the proliferation (55. 61%,P<0. 05) and DNA synthesis (76. 79%,P<0. 05) of MGc-803 cell line. It also inhibited the proliferation (62. 02%,P<0. 05) and DNA synthesis (76. 78%, P<0. 05) of SGc-7901 cell line. A reduction in intracellular P21 ras protein levels in MGc-803 cell line was observed 6 h after the treatment with ASO-r and maintained over 12 h. Another synthetic 15-mer targeted against the initiation codon and downstream 4 codons of c-myc proto-oncogene (ASOm) inhibited only DNA synthesis of MGc-803 cell line (71. 37%, P<0. 05). The control 15-mer did not inhibit the expression of P21 protein and proliferation of these cell lines. These experiments seemed to provide evidence that ASO-r could be effective in inhibiting the expression of c-Ha-ras proto-oncogene and controlling the growth of human gastric carcinoma cells,and that the over-expression of c-Ha-ras proto-oncogene might mainly be associated with the malignant proliferation of human gastric carcinoma cells.

Extraction of Phenolic Compounds from Olive Leaf Extracts and Their Effect on Proliferation of Human Carcinoma Cell Lines

The aim of this work was to evaluate the effect of different olive leaf extracts (OLE) from different leaf growing stages on human carcinoma cell lines. OLE were tested in human carcinoma cell lines in vitro and cells were plated in 96-microtiter culture plates for each OLE concentration. Fresh (F) and freeze-dried (FD) leaves exhibited phenolic compounds in the range of 2.09 ± 0.10 to 8.44 ± 0.64 and 7.72 ± 0.56 to 24.65 ± 1.9 mg gallic acid equivalents/g leaves, respectively. OLE from several Portuguese olive tree cultivars were found to inhibit the growth of human carcinoma cell lines in a range of 2.09 - 8.44 μg phenolic compound/well (209 - 844 μg/ml) and 0.07 - 2.40 μg phenolic compounds/well (7 - 240 μg/ml) for fresh and freeze-dried leaves, respectively. Young (Y) leaves have revealed the highest cell growth inhibition ranging from about 95% for Cobran?osa, followed by 90% for Cobran?osa, 90% for Arbequina and 75% for Arbequina for cell lines A549, HeLa, A431 and OE21, respectively. The lowest cell growth inhibition (35%) was observed for Galega (Y) leaf extract on cell line A549. However, FD samples exhibited a distinctive pattern since cell growth inhibition was highest at highest extract dilution tested, for A431 (Galega Y) followed by A549 (Cobran?osa Y) with cell inhibition of 75% and 70%, respectively. The data presented in this work strongly suggest that OLEs inhibit the growth of human carcinoma cell lines.

Establishment and characterization of a novel nasopharyngeal carcinoma cell line (SUNE2) from a Cantonese patient

The undifferentiated form of nasopharyngeal carcinoma (NPC) is the most common malignant head and neck cancer in South China, especially in Cantonese populations. However, few NPC cell lines have been established from the patients in this region. In this study, we established a new NPC cell line, termed SUNE2, from a Cantonese patient with undifferentiated NPC. This cell line had extremely low concentrations of Epstein-Barr virus (EBV) DNA in long-term culture and expressed low levels of latent membrane protein 1 (LMP1), latent membrane protein 2A (LMP2A), BamH1-A right frame 1 (BARF1), EBV-encoded RNA-1 (EBER1), and EBV-encoded RNA-2 (EBER2) in early passages. SUNE2 cells also showed much stronger transforming ability than 5-8F cells in colony formation assays and anchorage- independent growth assays in soft agar, and they only need 2 weeks to form tumors in nude mice. In summary, the SUNE2 cell line is a new in vitro model that can be used for further research on the mechanisms underlying the occurrence and development of NPC.

Pharmacological Isolation of Experimental Models of Drug-resistant Hepatocellular Carcinoma Cell Line

Drug resistance is one of the major challenges facing the success of chemotherapy against human hepatocarcinoma (HCC) as well as other types of cancer. Studies with cell lines can serve as initial screening for agents that could modulate drug resistance. Development of a good experimental model of drug-resistant cells is a prerequisite for the success of such cellular studies;but could be laborious and generally time-consuming. Additionally, the high mortality rate associated with advanced HCC calls for a probe into the mechanism of resistance by developing experimental model that mimics clinical method of its treatment. Consequently, we have reported a simplified method of selection of drug-resistant hepatocarcinoma cells from human hepatocellular carcinoma (HEPG2) cell line using pharmacologic agents, cisplatin (CDDP) and 5-fluorouracil (5-FU). HEPG2 cell line was incubated for 24 hours with different concentrations of CDDP (0 - 20 μM) or 5-FU (0 - 100 μM). Cell viability was assayed by CCK-8 (Cell Counting Kit) analysis, and the inhibitory concentrations (IC50) for CDDP and 5-FU were established by dose-dependent cytotoxicity curves. The IC50(s) were confirmed by flow cytometric analysis of cell death due to CDDP or 5-FU. Clinical method of treatment was imitated by treating the parental HEPG2 cell line in pulse, at the optimal concentration of either CDDP or 5-FU for 4 to 6 hours. Induction was repeated 6 times, whilst allowing the cells to attain at least 70% confluence between intervals of induction. The resultant drug-resistant sublines, (HEPG2CR) and (HEPG2FR) were found to be stable after over 3 months of drug withdrawal and maintenance in drug-free medium. This was done with the views of establishing a simple, efficient and direct protocol for the development of good cellular models for the study of drug resistance in liver cancer, with possible application in other cancer types.

THE DIFFERENTIATION INDUCING EFFECT OF TANSHINONE AND RETINOIC ACID ON HUMAN CERVICAL CARCINOMA CELL LINE（ME180） IN VITRO

The cervical carcinoma cell line, ME180 cells were treated with tanshinone (Tan) or retinoic acid (RA) in DMSO (final concentration 0.02%, V/V) on 4 successive days. The cells treated with the same concentration of DMSO alone served as control. Morphological studies with light and transmission electron microscopy showed that the cells treated with both Tan and RA became welldifferentiated. The cellular growth and proliferation were suppressed (as revealed by cell counting. [3H]-thymidine uptake and colony-forming assay). The number of nuclear organizer regions(AgNORs) in cells reduced and the distribution type returned nearly to normal type. The tumorigenicity in nude mice was reduced. The cell RNA dot hybridization showed that the expression of c-myc and c-Ha-ras mRNA was inhibited markedly. All above results showed that Tan and RA could reverse some malignant Phenotype and possessed differentiation inducing activity on ME180 cell line. No significant difference was observed between the cells treated with Tan and RA.

EFFECTS OF ANTISENSE EPIDERMAL GROWTH FACTOR AND ITSRECEPTOR RETROVIRAL EXPRESSION VECTORS ON CELLGROWTH OF HUMAN PANCREATIC CARCINOMA CELL LINE

A 150 bp epidermal growth factor (EGF) cDNA fragment and a 1024 bp epidermal growth factor receptor (EGFR) cDNA fragment were inserted into 5.05 kb pBabe-puro retroviral vectors between BamH I and EcoR I sites in 3'-5' and / or 5'-3' orientation. The vectors were ligated with EGF and EGFR fragments by T-4 Ligase. The recombinant retroviral vectors were then packaged with packaging cell line PA317 through calcium phosphate mediated transfection. The viral supernatant of transfected PA317 cell lines were used to infect the human pancreatic carcinoma cell line PC-7. The resultant transformant cell lines: PC-7 / AS-EGF, PC-7 / S-EGFR, PC-7 / AS-EGFR and PC-7 / pBabe were tested for their endogenous EGF and EGFR mRNA expressions, cell growth rate, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice. The results showed that there were noticeable inhibitions of cell growth, 3H-TdR incorporation rate, soft agar colony formation and tumorigenicity in nude mice in PC-7 / AS-EGF and PC-7 / AS-EGFR transformant cell lines. The endogenous EGF mRNA expression was blocked in PC-7 / AS-EGF cell line and the endogenous EGFR mRNA was significantly down-regulated in PC-7 / AS-EGFR cell line.

In vitro cytotoxic studies of red algae Portieria hornemannii and Spyridia fusiformis against Dalton’s lymphoma ascite and Ehrlich ascite carcinoma cell lines

Objective:To study the in vitro cytotoxic activities of methanol extract of Portieria hornemannii(P.hornemannii)and Spyridia fusiformis(S.fusiformis)using Dalton’s lymphoma ascite and Ehrlich ascite carcinoma cell lines.Methods:The effect of cytotoxicity of P.hornemannii and S.fusiformis was evaluated with the concentrations(100 to 200μg/mL)and assessed for the antitumour activity vs.the selected cell lines using Trypan blue assay.Results:The methanol extracts of P.hornemannii and S.fusiformis showed potent cytotoxic activity with IC_(50)values of(209.00±0.05)μg/mL and(190.00±0.05)μg/mL against the Dalton’s lymphoma ascite cell line and IC_(50)values of(190.00±0.05)μg/mL and(182.00±0.05)μg/mL against the Ehrlich ascite carcinoma cell line respectively.In vitro cytotoxicity against the tested cancer cell lines showed strong activity by the abnormal activities of algal residue in the normal cells.Conclusions:The methanol solvent residue of red algae(P.hornemannii and S.fusiformis)could be a good candidate.It would be a novel marine resource as a antitumor medicine demonstrated by cytotoxic studies that the above marine algae can be a potential candidate sources as antitumor drugs.