TIPRL, a Novel Tumor Suppressor, Suppresses Cell Migration, and Invasion Through Regulating AMPK/mTOR Signaling Pathway in Gastric Cancer.

Invasion and metastasis of gastric cancer after curative resection remain the most common lethal outcomes. However, our current understanding of the molecular mechanism underlying gastric cancer metastasis is far from complete. Herein, we identified TOR signaling pathway regulator (TIPRL) as a novel metastasis suppressor in gastric cancer through genome-wide gene expression profiling analysis using mRNA microarray. Decreased TIPRL expression was detected in clinical gastric cancer specimens, and low TIPRL expression was correlated with more-advanced TNM stage, distant metastasis, and poor clinical outcome. Moreover, TIPRL was identified as a direct target of miR-216a-5p and miR-383-5p. Functional study revealed that re-expression of TIPRL in gastric cancer cell lines suppressed their migratory and invasive capacities, whereas inverse effects were observed in TIPRL-deficient models. Mechanistically, TIPRL downstream effectors and signaling pathways were investigated using mRNA microarray. Gene expression profiling revealed that TIPRL could not modulate the downstream genes at transcriptional levels, thereby implying that the regulation might occur at the post-transcriptional levels. We further demonstrated that TIPRL induced phosphorylation/activation of AMPK, which in turn attenuated phosphorylation of mTOR, p70S6K, and 4E-BP1, thereby leading to inactivation of mTOR signaling and subsequent suppression of cell migration/invasion in gastric cancer. Taken together, TIPRL acts as a novel metastasis suppressor in gastric cancer, at least in part, through regulating AMPK/mTOR signaling, likely representing a promising target for new therapies in gastric cancer.

Anticancer Effects of Constituents of Herbs Targeting Osteosarcoma.

Osteosarcoma is a rare primary malignancy of bone that is prone to early metastasis. Resection surgery and chemotherapeutic regimens are current standard treatments for osteosarcoma. However, the long-term survival rate of patients with osteosarcoma is low due to a high risk of metastasis. Hence, a new approach is urgently needed to improve the treatment of osteosarcoma. Compared with chemotherapy, natural active constituents isolated from herbs exhibit less adverse effects and better anti-tumor effects. This study aimed to summarize the anticancer effects of constituents of herbs on the progression and metastasis of osteosarcoma cells. It showed that many constituents of herbs inhibited osteosarcoma by targeting proliferation, matrix metalloproteinases, integrin and cadherin, and angiogenesis. The findings might be beneficial for the development of new drugs and treatment strategies.

Clinical application of RT-nested PCR integrated with RFLP in Hantavirus detection and genotyping: a prospective study in Shandong Province, PR China.

The aim of the present study was to evaluate the clinical usefulness of applying RT-nested PCR along with RFLP as a method for diagnosis and genotypic differentiation of Hantavirus in the acute-stage sera of HFRS patients as compared to the ELISA technique. A prospective study of patients with suspected HFRS patients was carried out. Sera were collected for serological evaluation by ELISA and RT-nested PCR testing. Primers were selected from the published sequence of the S segment of HTNV strain 76-118 and SEOV strain SR-11, which made it possible to obtain an amplicon of 403 bp by RT-nested PCR. The genotypic differentiations of the RT-nested PCR amplicons were carried out by RFLP. Sequence analyses of the amplicons were used to confirm the accuracy of the results obtained by RFLP. Of the 48 acute-stage sera from suspected HFRS patients, 35 were ELISA-positive while 41 were positive by RT-nested PCR. With Hind III and Hinf I, RFLP profiles of the RT-nested PCR amplicons of the 41 positive sera exhibited two patterns. 33 had RFLP profiles similar to the reference strain R22, and thus belonged to the SEOV type. The other 8 samples which were collected during October-December had RFLP profiles similar to the reference strain 76-118, and thus belonged to the HTNV type. Sequence phylogenetic analysis of RT-nested PCR amplicons revealed sdp1, sdp2 YXL-2008, and sdp3 as close relatives of HTNV strain 76-118, while sdp22 and sdp37 as close relatives of SEOV strain Z37 and strain R22 located in two separate clusters in the phylogenetic tree. These results were identical to those acquired by RFLP. RT-nested PCR integrated with RFLP was a rapid, simple, accurate method for detecting and differentiating the genotypes of Hantavirus in the acute-stage sera of suspected HFRS patients. In Shandong province, the main genotypes of Hantavirus belonged to the SEOV types, while the HTNV types were observed during the autumn-winter season.

[Spatial niches of dominant zooplankton species in Sanmen Bay, Zhejiang Province of East China].

Ecological niche has close relations with inter-species competition and resources utilization, and thus, can be used as an indicator to symbolize the resources utilization capability of certain groups of related species. In this paper, the niche breadth and overlap of the dominant zooplankton species in the Sanmen Bay of Zhejiang were determined by Shannon's formula and Petraitis index, respectively, and the differentiation of the niche was studied by canonical correspondence analysis (CCA), aiming to approach the distribution features of coastal zooplankton and related affecting factors in the Bay. In the study area, some coastal species such as Zonosagitta bedoti, Centropages dorsispinatus, and brachyuran larvae had wider niche breadth than the pelagic species such as Flaccisagitta enflata and Pseudeuphausia sinica, and the species of different groups with prey-predator relation had a greater niche overlap than those of the same groups without this relation. The CCA analysis showed that the spatial distribution of the zooplankton was more affected by water temperature, salinity, and chlorophyll a content rather than nutrients. The spatial niche of the zooplankton species was correlated with their living habit, inter-species competition, and prey- predator relationship.

Enteroenteroanastomosis near adjacent ileocecal valve in infants.

AIM: To investigate the feasibility and the effectiveness of ileoileostomy in the region adjacent to the ileocecal valve, which can retain the ileocecal valve in infants. METHODS: This is a retrospective review of 48 patients who underwent ileoileostomy in the region adjacent to the ileocecal valve (group 1) and 34 patients who underwent ileocecal resections and ileotransversanastomosis (group 2). Patients were monitored for the time to flatus, resumption of eating, length of hospital stay after surgery, serum total bile acid, vitamin B12 and postoperative complications. RESULTS: The time to flatus, time until resumption of eating and post-operative length of hospital stay showed no statistically significant differences between the two groups. Serum total bile acid and vitamin B12 were not significantly different between the two groups at post-operative day 1 and day 3, but were significantly decreased at 1 wk after operation in group 2. None of the patients died or suffered from stomal leak in these two groups. However, the incidence of diarrhea, intestinal infection, disturbance of acid-base balance and water-electrolytes in group 1 was lower than in group 2. CONCLUSION: Ileoileostomy in the region adjacent to the ileocecal valve is safe and results in fewer complications than ileotransversanastomosis in infants.

[Effects of intranasal interferon gamma on transforming growth factor-ß1/Smad in rats with allergic rhinitis].

OBJECTIVE: To investigate the effects of intranasal interferon gamma (IFN-γ) on nasal mucosa remodeling and expression of transforming growth factor-ß1 (TGF-ß1), Smad2, Smad3, Smad7 in allergic rhinitis (AR) rat model. METHODS: Ovalbumin (OVA) and aluminum hydroxide were used to construct the AR model. Thirty AR rats were randomly divided into positive control group (group B, n = 10), IFN-γ treatment group (group C, n = 10) and negative control group (normal rats, n = 10). After the AR models were built, 50 µl PBS, 1 µg IFN-γ was dropped into the nasal cavity of each rat in group B and group C, from the fouth week to tenth week, twice a week. The nasal mucosa was collected on day 71 in order to observe the pathologic changes, and the expression of TGF-ß1, TGF-ß1 mRNA, Smad2 mRNA, Smad3 mRNA and Smad7 mRNA by immunohistochemistry and reverse transcriptase-polymerase chain reaction. RESULTS: Decreases of TGF-ß1, Smad2 and Smad3 mRNA were seen in nasal tissue of group C (0.59 ± 0.04, 0.39 ± 0.08, 0.46 ± 0.15) as compared with group B (0.82 ± 0.12, 0.70 ± 0.18, 0.95 ± 0.26), the differences were significant (q value were 3.15, 4.47, 3.03, all P < 0.05). The levels of Smad7 mRNA expression increased significantly (q = 2.98, P < 0.05) in group C (0.31 ± 0.05) as compared with group B (0.25 ± 0.06). Immunohistochemistry showed significant decrease of TGF-ß1 expression in the nasal tissue of group C much lesser than that in group B. CONCLUSIONS: Intranasal IFN-γ could decrease the expression of TGF-ß1, TGF-ß1 mRNA, Smad2 mRNA, Smad3 mRNA, increase the expression of Smad7 mRNA in AR rats model and inhibit the nasal mucosa remodeling.

The chronic effects of oil pollution on marine phytoplankton in a subtropical bay, China.

To evaluate the effects of crude oil water accommodated fraction (WAF) on marine phytoplankton community, natural phytoplankton collected seasonally from the Yueqing bay were exposed to eight groups of crude oil WAF for 15 days under laboratory conditions. Chlorophyll a and cell density were measured, and species of phytoplankton were identified every 24 h to reflect the change of phytoplankton community. The results showed that (1) High concentrations (≥ 2.28 mg l(-1)) of oil pollution would greatly restrain phytoplankton growth (p<0.001), decrease chlorophyll a content and cell density, whereas low concentrations (≤ 1.21 mg l(-1)) did not restrain its growth but rather promoted the phytoplankton growth. (2) The biodiversity, evenness, and species number of phytoplankton were all significantly influenced by crude oil WAF in all seasons (p<0.001). (3) The dominant species changes were different under different pollutant concentrations in different seasons. Different species had different tolerances to the oil pollution, thus leading to abnormal succession.

Increased plasma osteoprotegerin levels are associated with the presence and severity of acute coronary syndrome.

OBJECTIVE: The objective of this study was to explore the relationship between increased plasma osteoprotegerin (OPG) levels and acute coronary syndrome (ACS). METHODS: Plasma OPG levels from 85 subjects undergoing coronary artery angiography in three different groups, including ACS (n=45), stable angia pectoris (SAP) (n=20) and normal coronary artery (NCA) (n=20), were detected by ELISA. Twenty-two ascending aorta specimens were surgically taken from 8 ACS, 7 SAP and 7 NCA patients, and OPG mRNA expression in the specimens was detected by RT-PCR. In addition, 10 coronary artery sections each were selected from autopsy archives for the presence of vulnerable atherosclerosis plaques (VP), stable plaques (SP) or no plaques (NP) and OPG protein expression in the sections was detected by immunohistochemistry. RESULTS: Plasma OPG concentrations in the ACS group were significantly higher than those in the SAP or NCA group.The levels of plasma OPG in the 1-, 2- and 3-vessel disease subgroups of ACS were increasingly higher (P < 0.05 or 0.01). Multiple logistic regression analyses revealed a significant independent relation between plasma OPG concentration and the presence of ACS (P = 0.032, odd ratio = 1.006).Ascending aorta specimens from the ACS group had a greater OPG mRNA expression than those from the NCA or SAP group (P < 0.01). Sections with VP had a markedly higher OPG expression than sections with SP or NP (P < 0.05 and P < 0.01, respectively). CONCLUSIONS: Increased plasma osteoprotegerin levels are associated with the presence and severity of acute coronary syndrome.

[Effects of residual heat and chlorine in cooling water from coastal power plant on Calanus sinicus].

According to the practical operation of coastal power plant cooling system, a simulation study was conducted on the effects of residual heat and chlorine in the cooling water on Calanus sinicus. The results showed that the thermal tolerance of C. sinicus to the cooling water was decreased with increasing exposure duration but increased with increasing acclimation temperature. When the acclimation temperature was 16 degrees C-27 degrees C, the lethal temperature of C. sinicus under thermal shock for 15, 30 and 45 min was 29.9 degrees C-31.7 degrees C, 29.4 degrees C-31.0 degrees C and 28.9 degrees C-30.3 degrees C, and that of C. sinicus continually exposed to increasing temperature for 24 and 48 h was 26.9 degrees C-28.5 degrees C and 26.4 degrees C-28.0 degrees C, respectively. When the acclimation temperature increased to a certain degree, the thermal tolerance of C. sinicus maintained at a stable level. The toxicity of residual chlorine on C. sinicus enhanced with increasing acclimation temperature, temperature increment, and exposure duration.

[Thermal tolerance of some marine copepods].

By using experimental ecological methods, the 24 hours semi-lethal temperature (24 h LT50) of typical copepods living in the coastal area of East China Sea was determined to elucidate the effects of thermal discharge from power station on the coastal ecosystem. The results indicated that different copepods at same natural acclimated temperature and specific copepod at different initial acclimated temperature had different thermal tolerance capability. The 24h LT50 of Calanus sinicus and Sinocalanus tenellus at natural acclimated temperature 13.5 degrees C was 26.9 degrees C and 25.4 degrees C, of Acartiella sinensis and Corycaeus affinis at natural acclimated temperature 14.2 degrees C was 26.7 degrees C and 30.5 degrees C, and of Centropages dorsispinatus, Paracalanus crassirostris, Acartia spinicauda and Euterpina acutifrons at natural acclimated temperature 28.0 degrees C was 34.0 degrees C, 34.3 degrees C, 35.7 degrees C and 36.0 degrees C, respectively. The 24h LT50 of S. tenellus at natural acclimated temperature 13.5 degrees C and 23.5 degrees C was 25.4 degrees C and 33.0 degrees C, respectively.

[Expression and significance of NKG2D ligands in 13 tumor cell lines].

BACKGROUND & OBJECTIVE: The interaction between NKG2D and its ligands plays a major role in immune surveillance against tumor. This study was to observe the expression and analyze the significance of NKG2D ligands in 13 tumor cell lines. METHODS: The mRNA expression of NKG2D ligands in K562, Raji, PG, Hep2, HepG2, HeLa, HT29, M21, MDA231, SGC7901, Caski, HL-60 and Jurkat cells was measured by reverse transcription-polymerase chain reaction (RT-PCR). The cytotoxicity of natural killer (NK) cells to the tumor cells at different effector-to-target cell (E:T) ratios were detected by MTT assay. The expression of MICA protein was measured by SABC immunohistochemistry and Western blot. RESULTS: The 13 tumor cell lines expressed different levels of NKG2D ligands. MICA was highly expressed in Hep2 cells, but not expressed in Caski, PG, HL-60 and Raji cells. The expression of MICA and MICB were positively correlated to the cytotoxicity of NK cells (r=0.851, P<0.001; r=0.652, P<0.05). Except for ULBP3, the expression of ULBP1, 2, 4 had no correlations to the cytotoxicity of NK cells. CONCLUSION: Among the 6 human NKG2D ligands, the expression of MICA is most intimate to the cytotoxicity of NK cells to tumor cells, and its expression level may determine the degree of immune response of NK cells to tumor.

[Effects of surgical treatment for low birth weight neonates with critical acute abdomen].

OBJECTIVE: To evaluate the effects of the surgical treatment in critical acute abdomen in low birth weight neonates. METHODS: The clinical data of 228 neonates with critical acute abdomen who underwent surgical treatment from January 2000 to January 2003, aged (4.1 +/- 0.7) days (1 h-7 days), 141 being preterm infants and 87 being small for date infants, 26 with the birth weight < or = 2000 g and 202 with the birth weight of 2000 - 2500 g, and 83 cases admitted between Jan 2000 and Dec 2002 (first 3-year group) and 145 admitted between Jan 2003 and Jan 2006 (last 3-year group), were analyzed retrospective Follow-up was conducted for 4 approximately 48 months. RESULTS: Twenty-six pediatric patients died after operation with a hospital mortality rater of 11.4%. The mortality rates of the group of preterm infants, newborns with the birth body weight < or = 2000 g, and the first 3-year group were 14.89% (21/141), 53.84% (14/26), and 18.07% (15/83) respectively, all significantly higher than the full-term small for date infants, newborns with the birth weight of 2000 approximately 2500 g, and the last 3-year group [5.75% (5/87, chi(2) = 4.455, P < 0. 05), 5.94% (12/202, chi(2) = 52.324, P < 0. 01); and 7.59% (11/145, chi(2) = 5.745, P < 0. 05) respectively. Follow-up showed that all surviving infants had good gastrointestinal functions and approximately normal growth. CONCLUSION: Death of low birth weight neonates with critical acute abdomen is associated with premature birth and low birth weight. With the development of neonatal surgery, prenatal diagnosis, and perioperational therapy, the curative rate of critical acute abdomen in low birth weight neonates is increasing.

[Up-regulation of IFN-alpha on expression of MICA in the cervical carcinoma cell lines].

AIM: To investigate the effect of IFN-alpha on expression of MHC class I chain-related protein A (MICA) in the cervical carcinoma cell lines. METHODS: The cervical carcinoma cell lines (HeLa and Caski) were treated with IFN-alpha. The expression of MICA was measured by RT-PCR and by immunohistochemical staining. The cytotoxicity of human NK cells to the IFN-alpha treated cervical carcinoma cells was detected by MTT method. RESULTS: The mRNA and protein expression of MICA was up-regulated by IFN-alpha in HeLa and Caski cells in a time and dose-dependent manner. Compared to Caski cells which weakly expressed MICA, higher cytolytic activity of NK cells was found against HeLa cells, which expressed relatively higher level of MICA. After being treated with IFN-alpha for 3 d, the susceptibility of the two cervical carcinoma cells to NK cytolysis was increased significantly. CONCLUSION: IFN-alpha can up-regulate the MICA expression in the cervical carcinoma cell lines and thereby enhance the susceptibility to cytolysis of NK cells.

[Cloning of human NKG2D gene and its expression in CHO cells].

AIM: To construct a recombinant eukaryotic expression vector of human NK cell receptor NKG2D, and express the recombinant human NKG2D in CHO cells. METHODS: A NKG2D gene fragment, with a length of about 650 bp, was amplified from the NK-92 cell line by RT-PCR and was cloned to plasmid pGEM-T Easy. Then the cloned DNA fragment was sequenced. The recombinant plasmid pGEM-T Easy/NKG2D was digested with EcoR I and BamH I, and then NKG2D fragment was isolated and inserted into the corresponding restriction site on eukaryotic expression vector pEGFP-N1. The Lipofectin was used to transfect the recombinant eukaryotic expression plasmid in CHO cells. The expression level of NKG2D gene in transfected CHO cells was detected by fluorescence microscope, RT-PCR, Western blot and immunohistochemical staining. RESULTS: The length of cDNA fragment amplified by RT-PCR was consistent with that of NKG2D. DNA sequencing of pGEM-T Easy/NKG2D revealed that the cloned DNA sequence was identical to that of reported NKG2D. Green fluorescence was seen in transfected CHO cells by fluorescence microscope. Human NKG2D mRNA was highly expressed in transfected CHO cells. Western blot and Immunohistochemical staining detection showed that NKG2D was expressed in transfected cells. CONCLUSION: A recombinant eukaryotic expression vector of human NKG2D can be constructed and it can be expressed successfully in CHO cells.

Intervention of Tongxinluo capsule against vascular lesion of atherosclerosis and its effect on lectin-like oxidized low density lipoprotein receptor-1 expression in rabbits.

OBJECTIVE: To investigate the prevention by Tongxinluo capsule (TXL) of vascular lesions and its effect on the levels of protein and gene expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) of vascular wall in rabbits with atherosclerosis (AS), and to explore its possible mechanism against AS. METHODS: AS models were established by feeding New Zealand white rabbits with high-cholesterol diet, and 24 immature rabbits were randomly divided into the control group, model group and treated group (treated with TXL capsule). The indexes of total cholesterol (TC) and low density lipoprotein (LDL) levels were measured at the 16th week. The intima thickness and the plaque area of abdominal aorta were quantitatively analyzed by pathological morphological analysis, the expression of macrophage and smooth muscle cell (SMC) in intima were detected by immunohistochemical method and histologic segments were stained by Hematoxilin-Eosin (HE) to identify the degree of atherosclerotic lesion in the model group and the prevention by TXL. The LOX-1 gene and protein expression in abdominal aorta was detected by semi-quantitative RT-PCR and immunohistochemistry, respectively. RESULTS: In the model group, the levels of TC and LDL were significantly elevated, aortic intima thickened extensively, the intima area enhanced, and macrophages expression increased; the levels of LOX-1 gene and protein expression was up-regulated in endothelium and neo-intima of the abdominal aorta. The treatment with TXL reduced blood lipids, attenuated arterial intimal proliferation, markedly inhibited the expression of macrophage and excessively expressed the level of LOX-1. CONCLUSION: TXL has an inhibitory effect on blood lipids, and it can prevent the occurrence of vascular lesion and cure its development, and its protection against AS was possibly associated with a crucial endothelial protective action through lowering the expression of LOX-1 in vascular walls.

[Induction of uridine 5'-diphosphate-glucuronosyltransferase gene expression by sulforaphane and its mechanism: experimental study in human colon cancel cells].

OBJECTIVE: To study the induction of expression of uridine 5'-diphosphate (UDP)-glucuronosyltransferase (UGT) 1A in colon cancer cells by sulforaphane (SFN) and its possible mechanism. METHODS: Human colon cancer cells of the line Caco-2 were cultured and added with SFN of different terminal concentrations, all below the concentration of IC(50). RT-PCR was used to examine the expression of UGT1A mRNA induced by SFN. Western blotting was used to detect the expression of UGT1A protein. The glucuronidation rate of N-hydroxy-PhIP was measured by high performance liquid chromatography (HPLC). The nuclear localization of transcription factor Nrf2 was observed by confocal laser microscopy. RESULTS: (1) Expression of UGT1A mRNA was observed in the Cac0-2 cells induced by SFN of the concentrations of 10 micromol/L approximately 35 micromol/L in a dose-independent manner (P < 0.05). Sulforaphane of the concentration of 25 micromol/L induced the UGT1A mRNA expression time-dependently. The levels of UGT1A1, UGT1A8, and UGT1A10 mRNA expression were significantly increased in the cells treated with 25 micromol/L sulforaphane compared to that in the controls (P = 0.006, P = 0.017, and P = 0.008 respectively). (2) The UGT1A protein band intensity increased significantly in the Coco-2 cells treated with sulforaphane of the concentrations 10 micromol/L approximately 30 micromol/L for 24 h in comparison with the control cells. (3) When the microsomes from the untreated Caco-2 cells were incubated with N-hydroxy-PhIP there was a minor HPLC peak at the expected retention time for N-hydroxy-PhIP-N2-glucuronide. This peak was dramatically increased in the sulforaphane-treated cells, suggesting higher activities of glucuronidation of N-hydroxy-PhIP. (4) Cytoplasmic labeling of NF-E2-related factor 2 (Nrf2), a transcription factor, with no nuclear staining was observed in the non-stimulated cells, whereas an intense nuclear labeling was observed in the sulforaphane-treated cells, indicating the induction of nuclear translocation of Nrf2 by sulforaphane. CONCLUSION: (1) Low dose sulforaphane induces the expression of UGT1A, UGT1A1, UGT1A A8, and UGT1A A10 mRNA significantly. These changes are accompanied by an increase in UGT1A1 protein and increase in heterocyclic aromatic amine glucuronidation. (2) The induction of the phase II enzyme activity by SFN occurs at the transcriptional level and is regulated by Nrf2.

[The negative regulatory effect of IFN-gamma on cognitive function of human natural killer cells].

OBJECTIVE: To investigate the regulatory effect of IFN-gamma on recognition of target cells by human natural killer (NK) cells. METHODS: The cytotoxic activity of human NK cell lines (NK92, NKL) was detected by MTT method. Expression of NK cell receptors (NKG2D, NKG2A/B, KIR2DL1 and KIR2DS1) and MICA on target cells (the ligand of NKG2D) was measured by RT-PCR. RESULTS: Both NK92 and NKL cells exerted higher cytotoxicity to tumor cells with MICA expression, while tumors without MICA expression could resist NK cell lysis. IFN-gamma (> 1000 U/ml) inhibited NK lysis of tumor cells with MICA expression through down-regulating the expression of NKG2D, but up-regulating the expression of NKG2A/B and KIR2DL1. CONCLUSION: IFN-gamma has a negative effect on activation and cytotoxicity of human NK cells by altering the balance between the expression of activating and inhibitory receptors on NK cells in favor of inhibition. This may serve to limit NK cell over-activation in vivo.

[Influence of chemotherapy on Th1/Th2 cytokine switching in stomach cancer patients].

OBJECTIVE: To observe the influence of chemotherapy on the switching of Th1/Th2 cytokines in stomach cancer patients. METHODS: Th1/Th2 cytokine genes expressed by peripheral blood mononuclear cells of stomach cancer patients before and after chemotherapy were detected by RT-PCR. RESULTS: The expression of Th2 cytokines was dominant in patients before chemotherapy, and the dominancy became less marked after chemotherapy. CONCLUSION: The immune deviation with Th2 predominance in stomach cancer patients has a tendency to become reversed after chemotherapy.