Golgi phosphoprotein 3 promotes ovarian cancer progression and is associated with cisplatin resistance.

Background: Golgi phosphoprotein-3 (GOLPH 3) is involved in the development of several human cancers. However, the clinical significance and biological role of GOLPH 3 in ovarian cancer (OC) remains unknown. Methods: The expression of GOLPH 3 in OC cell lines was quantified using real-time quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The role of GOLPH 3 in tumorigenicity, migration, and invasion of OC cell lines by small interference RNA, scratch wound-healing assays, and transwell assays was detected. In addition, western blotting was used to determine whether GOLPH 3 is associated with the PI3K/AKT/mTOR signaling pathway. Furthermore, RT-qPCR verified whether GOLPH 3 is associated with drug resistance. Results: GOLPH 3-positive expression rate was higher in OC. Downregulation of GOLPH 3 markedly inhibited the migration and invasion and may be related to the PI3K/AKT/mTOR signal pathway. Moreover, the result of the experiment proved that GOLPH 3 enhances the sensitivity of OC to cisplatin by regulating ATP7A/B. GOLPH 3 promoted the invasion and migration of OC, and the mechanism may be related to the PI3K/Akt/mTOR pathway. In addition, inhibition of GOLPH 3 increased the sensitivity of OC cells to cisplatin, which may be associated with ATP7A/B. Conclusion: This study found that GOLPH3 may promote the migration and invasion of OC cells through PI3K/Akt/mTOR pathway. At the same time, low expression of GOLPH3 increased the sensitivity of OC cells to cisplatin.

[Effect of Celastrol Based on IRAK4/ERK/p38 Signaling Pathway on Proliferation and Apoptosis of Multiple Myeloma Cells].

OBJECTIVE: To investigate the effect of celastrol on the proliferation and apoptosis of human multiple myeloma (MM) cell lines, reveal the relationship between IRAK4/ERK/p38 signaling pathway and celastrol regulating the proliferation and apoptosis of H929 and ARP-1 cells, and explore whether celastrol combined with bortezomib has synergistic effect. METHODS: CCK-8 method was used to detect the viability of MM cell lines H929 and ARP-1 treated by different concentrations of celastrol, bortezomib, and their combination, and the synergistic effect was determined by Kim's formula. The apoptosis rate of H929 cells and necrosis rate of ARP-1 were detected by Annexin V/PI method. The expression of key proteins and apoptosis proteins in IRAK4/ERK/p38 signaling pathway were detected by Western blot. RESULTS: Celastrol could significantly inhibit the proliferation of H929 and ARP-1 cells (r=0.9018, r=0.9244) and induce apoptosis in a time-dependent manner. Compared with the control group, celastrol could significantly up-regulate the expression of PARP and cleaved caspase-3 while down-regulate the expression of p-IRAK4, p-ERK, and p-p38 in H929 and ARP-1 cells. Celastrol and bortezomib alone inhibited the proliferation of H929 and ARP-1 cells. Compared with celastrol and bortezomib alone, their combination had lower cell survival rate and higher apoptosis rate (P<0.05). CONCLUSION: Celastrol can inhibit the proliferation and promote the apoptosis of H929 and ARP-1 cells, which may be related to inhibiting the phosphorylation of IRAK4 and blocking the activation of IRAK4/ERK/p38 signaling pathway. Celastrol combined with bortezomib has synergistic effect, which can more effectively inhibit the proliferation and induce apoptosis of H929 and ARP-1 cells.

Outcome of atypia of undetermined significance/follicular lesion of undetermined significance in thyroid fine-needle aspirations: A six-year institutional experience.

BACKGROUND: Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) is one of six diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (BSRTC). The goal of our study is to assess the outcome of cases classified as AUS/FLUS at our institution. METHODS: AUS/FLUS cases were identified by computer searching of the thyroid fine-needle aspiration (FNA) cases performed between 2010 and 2016. Outcomes were categorized as: follow-up surgery, repeat FNA or no follow-up available. Demographics, ultrasound findings and FNA diagnostic criteria were reviewed for AUS/FLUS cases with follow-up surgical pathology diagnosis. RESULTS: Our AUS/FLUS thyroid FNA rate was 6% (117 out of 1984 FNAs). Only 15% of the AUS/FLUS cases had repeat FNA, while 41% underwent surgery. The risk of malignancy (ROM) for cases with follow-up surgery was 17%. When considering all AUS/FLUS cases, the ROM was 7%. Statistically, benign neoplasms were more likely to be single lesions on ultrasound comparing to malignant neoplasms, and to exhibit architectural atypia as opposed to non-neoplastic lesions on FNA. The malignancy rates among patients that directly went to surgical resection (17%) and patients having repeat FNA after the first AUS/FLUS diagnosis followed by surgery (29%) was not significantly different. However, repeat FNA was able to reclassify the majority of cases into more definitive categories. CONCLUSION: The outcome of the thyroid FNAs diagnosed as AUS/FLUS in our institution meets the benchmark statistics for AUS/FLUS rate and ROM. This study constitutes a valuable quality assurance measure and serves as a baseline for subsequent quality improvement.

Artificial Intelligence-Assisted Amphiregulin and Epiregulin IHC Predicts Panitumumab Benefit in RAS Wild-Type Metastatic Colorectal Cancer.

PURPOSE: High tumor mRNA levels of the EGFR ligands amphiregulin (AREG) and epiregulin (EREG) are associated with anti-EGFR agent response in metastatic colorectal cancer (mCRC). However, ligand RNA assays have not been adopted into routine practice due to issues with analytic precision and practicality. We investigated whether AREG/EREG IHC could predict benefit from the anti-EGFR agent panitumumab. EXPERIMENTAL DESIGN: Artificial intelligence algorithms were developed to assess AREG/EREG IHC in 274 patients from the PICCOLO trial of irinotecan with or without panitumumab (Ir vs. IrPan) in RAS wild-type mCRC. The primary endpoint was progression-free survival (PFS). Secondary endpoints were RECIST response rate (RR) and overall survival (OS). Models were repeated adjusting separately for BRAF mutation status and primary tumor location (PTL). RESULTS: High ligand expression was associated with significant PFS benefit from IrPan compared with Ir [8.0 vs. 3.2 months; HR, 0.54; 95% confidence interval (CI), 0.37-0.79; P = 0.001]; whereas low ligand expression was not (3.4 vs. 4.4 months; HR, 1.05; 95% CI, 0.74-1.49; P = 0.78). The ligand-treatment interaction was significant (P interaction = 0.02) and remained significant after adjustment for BRAF-mutation status and PTL. Likewise, RECIST RR was significantly improved in patients with high ligand expression (IrPan vs. Ir: 48% vs. 6%; P < 0.0001) but not those with low ligand expression (25% vs. 14%; P = 0.10; P interaction = 0.01). The effect on OS was similar but not statistically significant. CONCLUSIONS: AREG/EREG IHC identified patients who benefitted from the addition of panitumumab to irinotecan chemotherapy. IHC is a practicable assay that may be of use in routine practice.

[Analysis of Serum Metabonomics in Patients with Multiple Myeloma Based on Liquid Chromatography-Mass Spectrometry].

OBJECTIVE: To observe the changes of serum metabolites in patients with multiple myeloma (MM) by metabonomics, and explore the potential biomarkers for diagnosis, prognosis, and progression of MM. METHODS: Serum samples were collected from 26 patients with MM and 50 healthy controls. The data detected by liquid chromatography-mass spectrometry (LC-MS) was input into SIMCA-14.0 software for multivariate statistical analysis. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to analyze the changes of metabolites. RESULTS: The metabolic change of uric acid and trans-vaccenic acid in serum samples of MM patients was 9.39 times and 2.77 times of these in healthy people, respectively, which were significantly higher than those of healthy people, and the difference was statistically significant(P<0.01). CONCLUSION: Uric acid and trans-vaccenic acid are expected to be important metabolic indicators for the diagnosis, prognosis, and efficacy evaluation of MM, thus providing some clues for the pathogenesis of MM.

A novel acid polysaccharide from Boletus edulis: extraction, characteristics and antitumor activities in vitro.

A novel cold-water-soluble polysaccharide (BEP), with a molecular weight of 6.0 × 106 Da, was isolated from Boletus edulis. BEP consists of galactose, glucose, xylose, mannose, glucuronic, and galacturonic acid in a ratio of 0.34:0.28:0.28:2.57:1.00:0.44. The IR results showed that BEP was an acid polysaccharide, containing α-type and ß-type glucoside bonds. MTT assay showed BEP could inhibit cell proliferation significantly. Morphological observation demonstrated that BEP-treated MDA-MB-231 and Ca761 cells exhibited typical apoptotic morphological features. Flow cytometry analysis revealed that BEP caused mitochondrial membrane potential collapse. Annexin V-FITC/PI staining indicated that BEP induced apoptosis of MDA-MB-231 and Ca761 cells through cell block in S phase and G0/G1 phase, respectively. Western blot results showed that BEP could increase the Bax/Bcl-2 ratios, promote the release of cytochrome C, and activate the expression of caspase-3 and caspase-9 in MDA-MB-231 and Ca761 cells. In conclusion, our results demonstrated that BEP could inhibit the proliferation of breast cancer cells and induce apoptosis through mitochondrial pathways.

Xiyanping Plus Azithromycin Chemotherapy in Pediatric Patients with Mycoplasma pneumoniae Pneumonia: A Systematic Review and Meta-Analysis of Efficacy and Safety.

BACKGROUND: Xiyanping injection (XYP) is a well-known Chinese medicinal preparation reputed as a most effective alternative to antibiotics. XYP has been widely used in combination therapies to treat various infectious diseases, among which XYP plus azithromycin (AZM) chemotherapy is often used for the treatment of Mycoplasma pneumoniae pneumonia in pediatric patients (p-MPP) in China. OBJECTIVE: The present study just aimed to confirm whether XYP can improve the clinical efficacy and safety of AZM chemotherapy for p-MPP by performing meta-analysis and systematic review. METHODS: A meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The randomized controlled trials (RCTs) concerning XYP plus AZM chemotherapy for p-MPP were selected, for which the main outcomes included overall response rate (ORR), antipyretic time, cough disappearance time, lung wet Rales disappearance time, hospitalization duration, and adverse drug reactions (ADRs). Based on the data extracted, the meta-analysis was conducted by using a standard data extraction form. RESULTS: Nine RCTs involving 963 patients were included for meta-analysis. More concretely, the combination therapy showed the risk ratio (RR) and 95% confidence intervals (CI) of ORR and ADRs as (RR, 1.21 [95% CI, 1.15, 1.28]) and (RR, 0.37 [95% CI, 0.27, 0.51]), respectively. And other major outcomes were as follows: hospitalization durations (standard mean difference (SMD), -1.32 [95% CI, -1.48, -1.16]), antipyretic time (SMD, -1.26 [95% CI, -1.70, -0.83]), cough disappearance time (SMD, -1.07 [95% CI, -1.38, -0.75]), and the disappearance time of lung wet Rales (SMD, -0.83 [95% CI, -1.07, -0.60]). With statistically significant differences in various aspects, the combination therapy plus XYP displayed obvious advantages in contrast to AZM alone. CONCLUSION: Overall, XYP might reduce the incidence of ADRs and significantly improve the clinical efficacy for p-MPP receiving AZM chemotherapy.

A prospective analysis of touch preparation cytology for intraoperative detection of mediastinal lymph node metastases.

INTRODUCTION: Patients diagnosed with lung cancer may require immediate evaluation of mediastinal lymph nodes to determine treatment plan. Typically, frozen section (FS) analysis has been used, but this analysis can be time-consuming and uses more tissue than touch preparation (TP) cytologic analysis. TP accuracy has been studied in other organs, but no prospective studies comparing TP to FS have been performed on mediastinal lymph nodes in lung cancer. Our goal was to compare the accuracy of TP to FS in these cases. MATERIALS AND METHODS: After obtaining institutional review board approval, all patients undergoing mediastinal lymph node evaluation for a diagnosis of lung cancer were asked to participate. If consent was given, TP and FS analyses were performed on all mediastinal lymph node stations in all patients and compared to permanent hematoxylin and eosin analysis. Data were collected prospectively. RESULTS: Twenty patients were enrolled. Mean age was 67.7 years. Fifty-five percent (11 of 20) of patients were men. The mean number of lymph node stations sampled in each patient was 3.4. In predicting the stage of the patient, TP had a sensitivity and specificity of 95% and 100%, respectively. FS had a lower sensitivity, 85%, and a specificity of 100%. On permanent analysis, metastatic foci ranged in size from 0.15 mm to 1.5 mm. CONCLUSIONS: TP was more sensitive than FS in detecting mediastinal lymph node metastases. The technical difficulty of obtaining full-thickness sections without creating significant artifact may contribute to the lower sensitivity of FS in detecting micrometastases.

[Clinical and pathological features in IgA nephropathy with IgG deposition in the glomerular mesangial area].

OBJECTIVE: To investigate the relationship between the clinical and pathological findings in IgA nephropathy with or without IgG deposition in the glomerular mesangial area. METHODS: The data were collected from 122 patients with a diagnosis of IgA nephropathy by renal biopsy in the Third Affiliated Hospital of Southern Medical University between November, 2009 and February, 2016. All the samples were examined by light microscopy, immunofluorescence and electron microscopy. According to the results of immunofluorescence assay, the patients were divided into IgA group (n=63) and IgA-IgG group (n=59). The pathological classification of IgA nephropathy was analyzed according to Oxford classification and Lee's classification. The clinical and pathological findings were compared between the two groups. RESULTS: Compared with the patients with IgA nephropathy but without IgG deposition, patients with IgA nephropathy with IgG deposition had higher serum creatinine, higher 24-h urine protein, higher blood uric acid, higher triglyceride levels (P<0.05) and lower eGFR (P<0.05); more of these patients were in Lee's grade IV-V, had renal tubular atrophy and/or interstitial fibrosis, and had MEST scores more than 3 (P<0.05). CONCLUSION: Patients with IgA nephropathy with IgG deposition in the glomerular mesangial have severer clinical symptoms and more serious pathological changes. Measures should be taken to control IgG deposition in patients with IgA nephropathy to delay the progress of the disease.

Hydrogen sulfide mediates the protection of dietary restriction against renal senescence in aged F344 rats.

Renal aging is always accompanied by increased oxidative stress. Hydrogen sulfide (H2S) can be up-regulated by 50% dietary restriction (DR) for 7-day and can block mitochondrial oxidative stress. H2S production exerts a critical role in yeast, worm, and fruit fly models of DR-mediated longevity. In this study, we found that renal aging could be attenuated by 30% DR for 6-month (DR-6M) and life-long (DR-LL), but not for 6-week (DR-6W). The expressions of cystathionine-γ-lyase (CGL) and cystathionine-ß- synthase (CBS) were improved by DR-6M and DR-LL. Endogenous H2S production shared the same trend with CBS and CGL, while glutathione (GSH) didn't. When comparing efficiencies of DR for different durations, more evident production of H2S was found in DR-6M and DR-LL than in DR-6W. Finally the level of oxidative stress was improved by DR-6M and DR-LL rather than by DR-6W. It concluded that aged rats had the ability to produce enough H2S on 30% DR interventions protecting against renal aging, and the effect of DR for long-term were more significant than that of DR for short-term.

Beneficial Effects of Caloric Restriction on Chronic Kidney Disease in Rodent Models: A Meta-Analysis and Systematic Review.

BACKGROUND: Numerous studies have demonstrated the life-extending effect of caloric restriction. It is generally accepted that caloric restriction has health benefits, such as prolonging lifespan and delaying the onset and progression of CKD in various species, especially in rodent models. Although many studies have tested the efficacy of caloric restriction, no complete quantitative analysis of the potential beneficial effects of reducing caloric intake on the development and progression of CKD has been published. METHODS: All studies regarding the relationship between caloric restriction and chronic kidney diseases were searched in electronic databases, including PubMed/MEDLINE, EMBASE, Science Citation Index (SCI), OVID evidence-based medicine, Chinese Bio-medical Literature and Chinese science and technology periodicals (CNKI, VIP, and Wan Fang). The pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated by using fixed- or random-effects models. RESULTS: The data from 27 of all the studies mentioned above was used in the Meta analysis. Through the meta-analysis, we found that the parameter of blood urea nitrogen, serum creatinine and urinary protein levels of the AL group was significant higher than that of the CR group, which are 4.11 mg/dl, 0.08mg/dl and 33.20mg/kg/24h, respectively. The incidence of the nephropathy in the caloric restriction (CR) group was significantly lower than that in the ad libitum-fed (AL) group. We further introduced the subgroup analysis and found that the effect of caloric restriction on the occurrence of kidney disease was only significant with prolonged intervention; the beneficial effects of CR on the 60%-caloric-restriction group were greater than on the less-than-60%-caloric-restriction group, and caloric restriction did not show obvious protective effects in genetically modified strains. Moreover, survival rate of the caloric restriction group is much higher than that of the ad libitum-fed (AL) group. CONCLUSIONS: Our findings demonstrate for the first time that compared with the AL group, the caloric restriction indeed decreased urea nitrogen, creatinine, urine protein, incidence of kidney diseases and increased the survival rate on 700~800 days.

Anti-Inflamm-Aging Effects of Long-Term Caloric Restriction via Overexpression of SIGIRR to Inhibit NF-κB Signaling Pathway.

BACKGROUND: Chronic inflammation is thought to be a determinant of the aging rate and longevity. Caloric restriction (CR) attenuates age-related increases in the systemic levels of several pro-inflammatory mediators, but the anti-inflammatory mechanisms of CR in the aging process remain unclear. METHODS: Fisher 344 rats in a CR group were fed an amount of food corresponding to 60% of that fed to an ad libitum-fed (AL) group for 8 months. Biochemical analyses and renal pathological grading were used to analyze physiological status. Important signaling molecules in the Toll-like receptor/nuclear factor kappa-light-chain-enhancer of activated B cells (TLR/NF-κB) pathway were also analyzed by western blotting, immunofluorescence and immunohistochemistry. RESULTS: 1) Compared with AL feeding, CR decreased aging-mediated increases in both biochemical marker levels and renal pathological grading. 2) Single immunoglobulin IL-1 (IL-1)-related receptor (SIGIRR) expression decreased with increasing age, but CR led to overexpression. 3) The expression of TLR4 was significantly higher in the CR group than in the AL group. 4) SIGIRR overexpression decreased the expression of the adaptor molecules myeloid differentiation factor 88 (MyD88), IL-1 receptor-associated kinase 4 (IRAK4) and tumor necrosis factor receptor-associated factor 6 (TRAF6). 5) The levels of the inflammatory markers phospho-IκBα and phospho-NF-κB p65 decreased in the CR group. CONCLUSIONS: The inflammatory response might be alleviated by SIGIRR via blockade of the TLR4/NF-κB signaling pathway. Therefore, CR can decrease inflammation via SIGIRR overexpression, and SIGIRR might be a new target to delay aging.

Screening for differentially expressed genes in endophytic fungus strain 39 during co-culture with herbal extract of its host Dioscorea nipponica Makino.

Strain 39 is an endophytic fungus which was isolated from Dioscorea nipponica Makino (DNM). After Strain 39 co-cultured with ethanol extract of DNM rhizomes for several days, the content of saponins in this culture mixture would be obviously increased. To analyze the mechanism of this microbial transformation, we used the differential display reverse transcription polymerase chain reaction (DDRT-PCR) method to compare the transcriptomes between Strain 39 cultured in normal PD medium and in PD medium which added ethanol extract of DNM rhizomes. We amplified 29 DDRT-PCR bands using 12 primer combinations of three anchored primers and five random primers, and six bands were re-amplified. Analysis of real-time PCR and sequence alignment showed that three clones were up-regulated in sample group: squalene epoxidase, squalene synthase, and catalase, one clone was expressed only in sample group. The possible roles and origins of the above genes were discussed, and the molecular mechanism of Strain 39 biotransformation was speculated. This study is the first report of the molecular biotransformation mechanism of saponins production by endophytic fungus of DNM.

Performance of the microscopic observation drug susceptibility assay in pyrazinamide susceptibility testing for Mycobacterium tuberculosis.

BACKGROUND: Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis (M. tuberculosis) is difficult and time consuming by conventional methods. In this study, we aimed to evaluate the performance of the microscopic observation drug susceptibility (MODS) assay in the detection of pyrazinamide resistance in M. tuberculosis relative to the conventional Wayne assay and Lowenstein-Jensen (LJ) proportion method. METHODS: M. tuberculosis clinical isolates (n = 132) were tested by the MODS and the Wayne assay: the results were compared with those obtained by the LJ proportion method. Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods. RESULTS: Compared to the LJ results, the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively. Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant (3 tests), in 1 of the 4 strains (LJ only), in 42 of 48 strains (at least 1 test), but no mutations in 1 strain sensitive according to the MODS assay only. The MODS assay, Wayne assay and LJ proportion method provided results in a median time of 6, 7 and 26 days respectively. CONCLUSIONS: MODS assay offers a rapid, simple and reliable method for the detection of pyrazinamide resistance in M. tuberculosis and is an optimal alternative method in resource limited countries.

Crocin inhibits proliferation and nucleic acid synthesis and induces apoptosis in the human tongue squamous cell carcinoma cell line Tca8113.

BACKGROUND: Cancer chemoprevention is a proven effective strategy for oral squamous cell carcinoma (OSCC). The present study was designed to investigate the effects of crocin, a potential chemopreventive agent, on growth and DNA and RNA content in a human tongue squamous cell carcinoma cell line, Tca8113. METHODS: Tca8113 cells were treated with crocin for 24, 48, 72, and 96 h at concentrations of 0.1, 0.2, 0.4, and 0.8 mM. Tumor cell viability was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. In addition, Tca8113 cells were treated with 0.4 mM crocin and cytotoxic effects as an inducer of apoptosis were analyzed using flow cytometry. Furthermore, acridine orange (AO) staining and observation using laser scanning confocal microscopy (LSCM) were used to determine the effects of the drug on nucleic acid synthesis. RESULTS: Crocin decreased Tca8113 cell viability and growth remarkably at 24, 48, 72, and 96 h, in a concentration-dependent manner (P<0.05). In addition, 0.4 mM crocin significantly induced both early and late apoptosis of Tca8113 cells. Moreover, the cellular DNA and RNA content was significantly downregulated by 0.4 mM crocin compared with the negative control (P<0.01). CONCLUSIONS: Our observations support the feasibility of applying crocin as a chemoprophylactic agent and treatment for OSCCs.

Naturally-occurring estradiol-17beta-fatty acid esters, but not estradiol-17beta, preferentially induce mammary tumorigenesis in female rats: implications for an important role in human breast cancer.

Because mammary glands are surrounded by adipose tissues, we hypothesize that the ultra-lipophilic endogenous estrogen-17beta-fatty acid esters may have preferential hormonal and carcinogenic effects in mammary tissues compared to other target organs (such as the uterus and pituitary). This hypothesis is tested in the present study. We found that all 46 rats implanted with an estradiol-17beta pellet developed large pituitary tumors (average weight=251+/-103 mg) and had to be terminated early, but only 48% of them developed mammary tumors. In addition, approximately one-fourth of them developed a huge uterus. In the 26 animals implanted with a mixture containing estradiol-17beta-stearate and estradiol-17beta-palmitate (two representative estradiol-17beta-fatty acid esters) or in the 29 animals implanted with estradiol-17beta-stearate alone (in the same molar dose as estradiol-17beta), 73% and 79%, respectively, of them developed mammary tumors, whereas only 3 or 2 animals, respectively, had to be terminated early due to the presence of a large pituitary tumor. Both tumorous and normal mammary tissues contained much higher levels of estrogen esterase than other tissues, which catalyzes the releases of bioactive estrogens from their fatty acid esters. In conclusion, while estradiol-17beta is much stronger in inducing pituitary tumor (100% incidence) than mammary tumor, estradiol-17beta-fatty acid esters have a higher efficacy than estradiol-17beta in inducing mammary tumor and yet it only has little ability to induce uterine out-growth and pituitary tumorigenesis. This study establishes the endogenous estrogen-17beta-fatty acid esters as preferential inducers of mammary tumorigenesis.