Polyploid cells, which contain more than one set of chromosome pairs, are very common in nature. Polyploidy can provide cells with several potential benefits over their diploid counterparts, including an increase in cell size, contributing to organ growth and tissue homeostasis, and improving cellular robustness via increased tolerance to genomic stress and apoptotic signals. Here, we focus on why polyploidy in the cell occurs and which stress responses and molecular signals trigger cells to become polyploid. Moreover, we discuss its crucial roles in cell growth and tissue regeneration in the heart, liver, and other tissues.
Humans ; Liver ; Hepatocytes ; Cell Cycle ; Polyploidy ; Homeostasis

Objective: To explore the effect of dormant polyploid giant cancer cells (PGCC) on nasopharyngeal carcinoma (NPC) recurrence and to clarify the role of inhibition of autophagy in inhibiting NPC-PGCC formation and preventing NPC recurrence. Methods: NPC cells-derived PGCC (NPC-PGCC) were induced by paclitaxel (PTX), and the morphology, polyploid characteristics and cell activity of PGCC were identified by light microscopy, immunofluorescence and Live/Dead cell double staining assays. RNA-seq was used to analyze the differentially expressed genes between NPC-PGCC and diploid nasopharyngeal carcinoma cells CNE2. Functional enrichment and pathway annotation analysis of differentially expressed genes were performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG). The level of autophagy in NPC-PGCC cells was assessed by Western Blot and transmission electron microscopy analysis. The role of autophagy in the formation of NPC-PGCC and the effect of NPC-PGCC on the recurrence of nasopharyngeal carcinoma were studied using a highly clinically relevant mouse nasopharyngeal carcinoma recurrence model. Statistical analysis was performed using GraphPad Prism 6 and P-values<0.05 were considered statistically significant. Results: NPC-PGCC induced by paclitaxel had the characteristics of burst-like division after dormancy. GO enrichment and KEGG pathway analyses identified the significant biological processes and pathways mainly concentrated in autophagy and related pathways involving the differentially expressed genes between NPC-PGCC and diploid nasopharyngeal carcinoma cells CNE2. The autophagy level was significantly enhanced in NPC-PGCC cells. In a highly clinically relevant mouse nasopharyngeal carcinoma recurrence model, the number of PGCC in the primary tumor of the nude mice treated with cisplatin were higher than those of the other groups. In nude mice pretreated with autophagy inhibitor and then co-treatment with autophagy inhibitor and cisplatin, the number of PGCC in primary tumors was less and the recurrence rate was significantly lower than in other groups. Conclusions: The mechanism of dormant polyploid giant cancer cells formation is related to autophagy. Inhibition of autophagy can inhibit the formation of PGCC and thus prevent the recurrence of nasopharyngeal carcinoma.
Animals ; Autophagy ; Carcinoma/genetics* ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Cisplatin/pharmacology* ; Gene Expression Regulation, Neoplastic ; Mice ; Mice, Nude ; Nasopharyngeal Carcinoma/genetics* ; Nasopharyngeal Neoplasms/pathology* ; Paclitaxel/pharmacology* ; Polyploidy

Lycophytes and seed plants constitute the typical vascular plants. Lycophytes have been thought to have no paleo-polyploidization although the event is known to be critical for the fast expansion of seed plants. Here, genomic analyses including the homologous gene dot plot analysis detected multiple paleo-polyploidization events, with one occurring approximately 13-15 million years ago (MYA) and another about 125-142 MYA, during the evolution of the genome of Selaginella moellendorffii, a model lycophyte. In addition, comparative analysis of reconstructed ancestral genomes of lycophytes and angiosperms suggested that lycophytes were affected by more paleo-polyploidization events than seed plants. Results from the present genomic analyses indicate that paleo-polyploidization has contributed to the successful establishment of both lineages-lycophytes and seed plants-of vascular plants.
Evolution, Molecular ; Genome, Plant ; Genomics ; Phylogeny ; Polyploidy ; Selaginellaceae/genetics*

Andrographis paniculata (Burm. f.) Nees (AP) is commonly used for the treatment of many infectious diseases and has been cultivated widely in Asian countries, and has been included in United States Pharmacopoeia as a dietary supplement, but the cultivars of A. paniculata are not abundant due to its self-pollinated. With the aims to enrich AP resources and provide materials for after breeding we explored the polyploidy induction. Different explants, colchicine concentration, and treatment time were tested. After identification by flow cytometry, eleven polyploid plants with different morphologic traits were obtained. The agronomic traits and andrographolide concentration of the polyploids were improved greatly. One of the polyploids (serial 3-7) was chosen for further study. The traits of the second and third generation polyploids (serial 3-7) were stable. Compared with the normal plants, the seeds (2nd generation) weight increased by 31%, and the andrographolide concentration of the leaves increased by 14% (2nd) and 28% (3rd). In conclusion, AP autopolyploids with different morphologic traits were established successfully for the first time, and the polyploids induction might be effective for crop improvement of AP.
Andrographis ; chemistry ; genetics ; growth & development ; Breeding ; Cell Culture Techniques ; Plant Extracts ; chemistry ; Polyploidy

By genetic transformation with Agrobacterum rhizogenes and artificial chromosome doubling techniques, we studied the induction of hairy roots and their polyploidization, and subsequent plant regeneration and nicotine determination to enhance the content of nicotine in Nicotiana tabacum. The results show that hairy roots could be induced from the basal surface of leaf explants of N. tabacum 8 days after inoculation with Agrobacterium rhizogenes ATCC15834. The percentage of the rooting leaf explants was 100% 15 days after inoculation. The hairy roots could grow rapidly and autonomously on solid or liquid phytohormones-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and paper electrophoresis of opines from N. tabacum hairy roots. The highest rate of polyploidy induction, more than 64.71%, was obtained after treatment of hairy roots with 0.1% colchicine for 36 h. The optimum medium for plant regeneration from polyploid hairy roots was MS+2.0 mg/L 6-BA +0.2 mg/L NAA. Compared with the control diploid plants, the hairy roots-regenerated plants had weak apical dominance, more axillary buds and more narrow leaves; whereas the polyploid hairy root-regenerated plants had thicker stems, shorter internodes and the colour, width and thickness of leaves were significantly higher than that of the control. Observation of the number of chromosomes in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 96 (4n = 96) chromosomes. Pot-grown experiments showed compared to the control, the flowering was delayed by 21 days in diploid hairy roots-regenerated plants and polyploid hairy root-regenerated plants. GC-MS detection shows that the content of nicotine in polyploid plants was about 6.90 and 4.57 times the control and the diploid hairy roots-regenerated plants, respectively.
Agrobacterium ; Plant Roots ; growth & development ; Plants, Genetically Modified ; growth & development ; Polyploidy ; Regeneration ; Tobacco ; genetics ; growth & development ; Transformation, Genetic

OBJECTIVETo investigate the concordance of dual-color silver enhanced in-situ hybridization (DSISH) and immunohistochemistry (IHC) in the detection of HER2 gene amplification and expression and to evaluate the values of DSISH in detecting HER2 gene status in gastric carcinoma.

METHODSBy using automated DSISH and IHC, HER2 gene status was detected in 230 cases of gastric cancer.

RESULTSAmong the 230 cases of gastric carcinoma tested by DSISH, 43 cases were positive and 187 cases were negative; HER2 gene amplification rate was 18.7% (43/230). The expression of HER2 protein was negative, weakly, moderately and strongly positive in 115, 69, 15 and 31 cases, respectively, by IHC. HER2 protein positive rate was 13.5% (31/230). Of the 43 HER2 gene amplification cases by DSISH, 2, 10, 2 and 29 cases were negative, weakly, moderately and strongly positive by IHC; Of the 187 HER2 negative cases by DSISH, 113, 59, 13 and 2 cases were negative, weakly, moderately and strongly positive by IHC, respectively. The overall concordance of HER2 status in the investigation between IHC and DSIDH was 93.5% (201/215), with a high consistency (Kappa coefficient 0.767, P < 0.01).

CONCLUSIONSDSISH can be applied to detect the HER2 gene status in gastric cancer and it also has a high consistency with the result of IHC. In addition, due to frequent heterogeneous expression of HER2, cases with moderate HER2 protein expression may need further assessment by DSISH.

Adult ; Aged ; Aged, 80 and over ; Esophagogastric Junction ; Female ; Gene Amplification ; Genes, erbB-2 ; Humans ; Immunohistochemistry ; In Situ Hybridization ; methods ; In Situ Hybridization, Fluorescence ; Male ; Middle Aged ; Phosphoproteins ; genetics ; metabolism ; Polyploidy ; Receptor, ErbB-2 ; metabolism ; Silver Staining ; Stomach Neoplasms ; genetics ; metabolism

Abstract: In order to enhance the content of secondary metabolites patchouli alcohol in Pogostemon cablin, we induced polyploid hairy roots and their plant regeneration, and determined the content of patchouli alcohol through artificial chromosome doubling with colchicine. The highest rate of polyploidy induction was more than 40% when hairy roots were treated with 0.05% colchicine for 36 h. The obtained polyploid hairy roots formed adventitious shoots when cultured in an MS medium with 6-BA 0.2 mg/L and NAA 0.1 mg/L for 60 d. Compared with the control diploid plants, the polyploid hairy root-regenerated plants of P. cablin had more developed root systems, thicker stems, shorter internodes and longer, wider and thicker leaves. Observation of the chromosome number in their root tip cells reveals that the obtained polyploid regenerated plants were tetraploidy, with 128 (4n = 128) chromosomes. The leaves contained around twice as many stomatal guard cells and chloroplasts as the controls, but the stomatal density declined with increasing ploidy. The stomatal density in diploid plants was around 1.67 times of that in polyploid plants. GC-MS analysis shows that the content of patchouli alcholol in the hairy root-derived polyploid plants was about 4.25 mg/g dry weight, which was 2.3 times of that in diploid plants. The present study demonstrates that polyploidization of hairy roots can stimulate the content of patchouli alcholol in medicinal plant of P. cablin.
Colchicine ; Diploidy ; Lamiaceae ; genetics ; growth & development ; Plant Roots ; growth & development ; Plants, Medicinal ; genetics ; growth & development ; Polyploidy ; Regeneration ; Sesquiterpenes ; chemistry

Acute myeloid leukemia (AML) is a phenotypically heterogeneous disorder. The M4 subtype of AML is frequently associated with the cytogenetic marker inversion 16 and/or the presence of eosinophilia. Blast crisis is the aggressive phase of the triphasic chronic myeloid leukemia (CML), which is a disease with Philadelphia(Ph) chromosome as the major abnormality. In the present study, we report a 76-year-old patient suspected of having AML with eosinophilic differentiation (AML-M4), which in clinical tests resembles CML blast crisis with multiple chromosomal abnormalities. Isochromosome 21 [i(21)(q10)] was the most recurrent feature noted in metaphases with 46 chromosomes. Ring chromosome, tetraploid endoreduplication, recurrent aneuploid clones with loss of X chromosome, monosomy 17, monosomy 7, and structural variation translocation (9;14) were also observed in this patient. Fluorescent in situ hybridization (FISH) confirmed the absence of Ph chromosome. This report shows how cytogenetic analyses revealed atypical structural aberrations in the M4 subtype of AML.
Aged ; Blast Crisis ; genetics ; Chromosome Aberrations ; Chromosome Deletion ; Chromosomes, Human, Pair 14 ; genetics ; Chromosomes, Human, Pair 17 ; genetics ; Chromosomes, Human, Pair 21 ; genetics ; Chromosomes, Human, Pair 7 ; genetics ; Chromosomes, Human, Pair 9 ; genetics ; Chromosomes, Human, X ; genetics ; Cytogenetic Analysis ; Endoreduplication ; Humans ; In Situ Hybridization, Fluorescence ; Isochromosomes ; Leukemia, Myelomonocytic, Acute ; genetics ; pathology ; Male ; Philadelphia Chromosome ; Polyploidy ; Ring Chromosomes ; Translocation, Genetic

OBJECTIVETo investigate the changes of drug sensitivity of spindle poison-induced polyploid tumor cells to chemotherapeutic agents and its possible mechanism.

METHODSNocodazole in a dose of 100 ng/ml was used to induce polyploidization in a breast cancer cell line MDA-MB-231 cells. The polyploid cells (T-MDA-MB-231) were sorted by flow cytometry. The morphological changes and proliferation of T-MDA-MB-231 cells were compared with that of MDA-MB-231 cells. The cell growth inhibition was assessed by MTT assay. The cells were treated with paclitaxel, docetaxel, vincristine, epirubicin, 5-Fu, VP16 and oxaliplatin, respectively. Those cells were labeled with annexin V-FITC/PI and analyzed by flow cytometry. Bcl-2 was knocked down in T-MDA-MB-231 cells using SiRNA and their growth inhibition was evaluated by MTT assay to evaluate the reversing effect of Bcl-2-silencing on drug resistance.

RESULTSThe polyploid T-MDA-MB-231 cells grew in vitro continuously and maintained constant DNA content. They had a larger cell size, and grew more slowly than MDA-MB-231 cells. The IC(50(s)) of T-MDA-MB-231 cells were significantly higher than that of the MDA-MB-231 cells: paclitaxel: (6.37 ± 0.07) vs. (2.05 ± 0.83) µmol/L; docetaxel: (32.98 ± 1.48) vs. (11.95 ± 0.98) µmol/L; vincristine: (35.28 ± 1.66) vs. (14.58 ± 0.94) µmol/L; oxaliplatin: (19.07 ± 0.45) vs. (9.75 ± 1.05) µmol/L; 5-Fu: (85.49 ± 3.21) vs. (31.35 ± 1.51) µmol/L; and epirubicin: (0.53 ± 0.06) vs. (0.15 ± 0.01) µmol/L, (all P < 0.05). The IC(50(s)) of VP16 in T-MDA-MB-231 cells was (2.85 ± 0.50)µmol/L, significantly lower than the (12.20 ± 1.55) µmol/L in MDA-MB-231 cells (P < 0.05), and that of T-MDA-MB-231 cells after Bcl-2-knocked down by siRNA was (19.59 ± 0.48) µmol/L, significantly higher than the (12.20 ± 1.55) µmol/L in the MDA-MB-231 cells (P < 0.05). The IC(50(s)) of docetaxel of T-MDA-MB-231 cells after Bcl-2-knocked down by siRNA was (21.52 ± 0.68) µmol/L, significantly decreased and lower than that before Bcl-2 silencing (32.98 ± 1.48) µmol/L.

CONCLUSIONSOur results indicate that polyploid tumor cells induced by spindle poison Nocodazole are more resistant to most of chemotherapeutic drugs. Downregulation of Bcl-2 increases the sensitivity of polyploid cells to docetaxel. The high expression of Bcl-2 may be one of the drug resistance mechanisms of polyploid tumor cells. The polyploid tumor cells are relatively sensitive to VP16, suggesting that VP16 might be an effective candidate drug for treatment of chemoresistant polyploid tumors.

Antineoplastic Agents ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Down-Regulation ; Drug Resistance, Neoplasm ; Epirubicin ; pharmacology ; Etoposide ; pharmacology ; Female ; Fluorouracil ; pharmacology ; Gene Knockdown Techniques ; Humans ; Inhibitory Concentration 50 ; Nocodazole ; pharmacology ; Organoplatinum Compounds ; pharmacology ; Paclitaxel ; pharmacology ; Polyploidy ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Taxoids ; pharmacology ; Vincristine ; pharmacology

OBJECTIVETo establish and characterize a lung adenocarcinoma cell line from a female patient in Xuanwei, Yunnan province.

METHODSSurgical specimen of the lung adenocarcinoma was obtained and cultured immediately in RPMI 1640 medium with 10% fetal bovine serum and 10(5) U/L penicillin and 100 mg/L streptomycin. When stable proliferation of the cells was achieved after over 40 passages in culture, the biological features of the cell line were investigated by cell morphology, karyotyping, protein marker expression [cytokeratins (CKs), epithelial membrane antigen (EMA) and CD proteins], growth kinetics, cell cycle phase distribution, mitotic index, colony formation in soft agar, cell invasion and tumorigenicity in Balb/c nude mice.

RESULTSThe established cell line was stably cultured for over 80 passages during a one-year period as an anchorage-dependent monolayer of short spindle, polygonal to epithelioid cells under phase contrast microscope. Microglandular cavities and disordered microfilaments were observed under transmission electron microscope. The growth curve presented in an "S" shape with the cell population doubled every 46.7 hours. The mitotic index was 1.5% and the colony formation rate was 8.3%. The cell cycle distribution included 76.9% in G(0)/G(1), 15.1% in S and 8.0% in G(2)/M. The cell line displayed a hypotriploid karyotype with a mode of 66 chromosomes and a median of 64 chromosomes. The cells expressed CK7, CK8, CK (Pan) and EMA by immunohistochemistry. A high level of cell surface expression of CD13 and CD59 was evident by flow cytometry. The cells were able to penetrate Matrigel in vitro but failed to form a stable xenograft in nude mice.

CONCLUSIONA new human lung adenocarcinoma cell line, designated as XLA-07, is successfully established from a Xuanwei lung cancer patient.

Adenocarcinoma ; metabolism ; pathology ; Animals ; CD13 Antigens ; metabolism ; CD59 Antigens ; metabolism ; Cell Culture Techniques ; Cell Cycle ; Cell Line, Tumor ; ultrastructure ; Cell Proliferation ; Female ; Humans ; Karyotyping ; Keratins ; metabolism ; Lung Neoplasms ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Mucin-1 ; metabolism ; Neoplasm Transplantation ; Polyploidy ; Tumor Stem Cell Assay