Arbuscular mycorrhizal fungi improve the growth and disease resistance of the invasive plant Wedelia trilobata.

AIMS: Arbuscular mycorrhizal fungi (AMF) are symbiotic partners of many invasive plants, however, it is still unclear how AMF contribute to traits that are important for the successful invasion of their host and how environmental factors, such as nutrient conditions, influence this. This study was to explore the effects of Glomus versiforme (GV) and Glomus mosseae (GM) on the growth and disease resistance of the invasive plant Wedelia trilobata under different nutrient conditions. METHODS AND RESULTS: We found that GV and GM had higher root colonization rates resulting in faster W. trilobata growth under both low-N and low-P nutrient conditions compared to the normal condition. Also, the colonization of W. trilobata by GV significantly reduced the infection area of the pathogenic fungus Rhizoctonia solani under low-N conditions. CONCLUSIONS: These results demonstrated that AMF can promote the growth and pathogenic defence of W. trilobata in a nutrient-poor environment, which might contribute to their successful invasion into certain type of habitats. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we report for the first time that AMF can promote growth and disease resistance of W. trilobata under nutrient-poor environment, which contribute to a better understanding of plant invasion.

Sensitization of TRAIL-resistant cervical cancer cells through combination of TRAIL and fucoxanthin treatments.

OBJECTIVE: Cervical cancer, the second most common cause of cancer death in women worldwide, is a malignant neoplasm arising from cells originating in the cervix uteri. Currently, surgery combined with chemo- and radiotherapy is the major therapeutic approach for women with early-stage cervical cancer. However, recurrent cervical cancers from acquired chemo-resistance remain a major cause of therapeutic failure. MATERIALS AND METHODS: In this study, we assessed the effects of the combination of TRAIL with fucoxanthin, which has been reported to suppress the cervical cancer cells growth on the cervical cancer treatments. HeLa cells, SiHa cells, and CaSki cells were used as in vitro model. Mice xenograft was used as in vivo model. TRAIL-resistant cells were generated from CaSki cell line. The activity of PI3K/Akt pathway was detected by Western blot. Cell viability was measured by MTT assay. RESULTS: We observed TRAIL-resistant cervical cancer cells were more sensitive to fucoxanthin treatments. By establishing a TRAIL-resistant cell line from CaSki, we found the TRAIL-resistant cells showed upregulated PI3K/Akt pathway. Moreover, CaSki TRAIL-resistant cells were more sensitive to the combination of TRAIL with either Akt inhibitor or fucoxanthin than treatment with TRAIL or fucoxanthin alone. Our in vitro and in vivo xenograft experiments demonstrate that the combination of TRAIL with fucoxanthin showed synergistically inhibitory effects on cervical cancer cells. CONCLUSIONS: The findings of this study suggest that the combined use of fucoxanthin and TRAIL might be a useful strategy against TRAIL-resistant cervical cancer.

Positive expression of insulin-like growth factor-1 receptor is associated with a positive hormone receptor status in ovarian cancer.

UNLABELLED: Summary PURPOSE: Ovarian cancer is the most deadly of all gynecologic malignancies, due in part to the diagnosis at an advanced stage caused by the deficiency of specific marks and symptoms, by the absence of reliable tests for screening, and by early detection. MATERIALS AND METHODS: Insulin-like growth factor-I (IGF-I) is known to be involved in the development and promotion of diverse examples of solid tumors including ovarian cancer. IGF-I levels in local tissue are subject to both endocrine and paracrine/autocrine regulation. RESULTS: Most patients will react initially to treatment, but almost 70% of them will have a recurrence. Consequently, new therapeutic modalities are urgently required to overcome chemoresistance observed in ovarian cancer patients. IGF-1R expression was evaluated immunohistochemically in tissue microarray blocks constructed from 1,200 ovarian cancer samples collected from three medical institutions. CONCLUSION: Evidence accumulates suggesting that the insulin/insulin growth factor (IGF) pathways could play a good therapeutic target in various cancers, including ovarian cancer.

Apoptosis and hormonal milieu in ductal system of normal prostate and benign prostatic hyperplasia.

AIM: To study the apoptotic rate (AR) and the androgen and estrogen milieu in the proximal and distal ductal systems of prostate, in order to help exploring the effects of these factors on prostatic growth and the pathogenesis of benign prostatic hypertrophy (BPH). METHODS: The proximal and distal ends of the ductal system were incised from 20 normal prostate as well as the hypertrophic prostate tissue from 20 patients with BPH. The AR was determined by the DNA end-labeling method and dihydrotestosterone (DHT) and estrodiol (E2), by radioimmunoassay. RESULTS: There was no significant difference in DHT and E2 density between the proximal and distal ends of the ductal systems in normal prostate. E2 appeared to be higher in BPH than in normal prostatic tissues, but the difference was statistically insignificant. In normal prostatic tissue, the AR was significantly higher in the distal than in the proximal ends of the ductal system (P < 0.05), while the AR of the proximal ends was significantly higher (P < 0.01) than that in the BPH tissue. No significant correlation was noted between the DHT and E2 density and the AR both in the normal prostate and BPH tissues. CONCLUSION: The paper is the first time describing a difference in AR in different regions of the ductal system of normal prostate, while the hormonal milieu is similar, indicating a functional inhomogeneity of these regions. A low AR in the proximal duct, where BPH originates, and an even lower AR in the BPH tissue, suggesting the participation of apoptosis in the BPH pathogenesis.

In vitro characterization of the myelotoxicity of cyclopentenyl cytosine.

We studied the toxicity of a new experimental anticancer drug, cyclopentenyl cytosine (CPE-C), to human and murine hematopoietic progenitor cells in vitro. Due to CPE-C's in vivo myelotoxicity, it was important to characterize its potential adverse effects on human marrow cells during preclinical development of the drug. Marrow cells were exposed to CPE-C for either 1 h prior to addition in clonal assays or continuously during their culture period. The inhibitory effects of CPE-C on myeloid (CFU-gm) and erythroid (CFU-e, BFU-e) colony formation were concentration- and time-dependent, with continuous CPE-C exposure being significantly more inhibitory than 1-h exposure. The results of both exposure experiments were combined to investigate colony inhibition as a function of overall drug exposure (concentration x time, AUC) and data analyzed by the nonlinear Emax equation. Human and murine CFU-gm had similar AUC-response curves and IAUC70 values (i.e., AUC at 70% colony inhibition) of 40.8 and 41.9 microM h, respectively. In contrast, murine CFU-e and BFU-e were more sensitive to CPE-C, having lower IAUC70 values (both, 21.1 microM h) than human CFU-e and BFU-e (107.8 and 33.0 microM h, respectively). This difference was most prominent with the late erythroid progenitor, CFU-e, in that the human cells were 5 times more resistant to inhibition by CPE-C. CPE-C was myelotoxic in vitro to human and murine marrow cells and toxicity correlated with overall drug exposure.

Myelotoxicity of rifabutin and 3'-azido-3'-deoxythymidine, alone and in combination, to human hematopoietic progenitor cells in vitro.

Mycobacterial infection is a common complication of acquired immunodeficiency syndrome (AIDS) frequently requiring antimycobacterial medication. It was of interest to determine if one such agent, rifabutin, could be tolerated by AIDS patients in conjunction with 3'-azido-3'-deoxythymidine (AZT) therapy. We evaluated the in vitro myelotoxic effects of rifabutin on human hematopoietic progenitor cells, alone and in combination with AZT (rifabutin: AZT, 1:10 ratio) over a range of concentrations in a microcapillary assay. Both rifabutin and AZT at 5 microM were moderately toxic to hematopoietic progenitors, inhibiting colony formation by 57-65% and 59-63%, respectively. The combination of rifabutin (5 microM) and AZT (50 microM) inhibited colony formation by 59-73%. Granulocyte-macrophage progenitors were less sensitive to this combination than erythroid progenitors. The combination of ribabutin and AZT did not exceed the in vitro myelotoxicity to human progenitors of AZT alone. These results suggest that rifabutin may be tolerated in AIDS patients, with no anticipated increase in myelotoxicity when given with AZT.

Comparative in vitro myelotoxicity of FCE 24517, a distamycin derivative, to human, canine and murine hematopoietic progenitor cells.

FCE 24517, a derivative of distamycin A, exhibits an unusual antitumor profile in experimental models. As part of its preclinical development, we evaluated the in vitro myelotoxicity of FCE 24517 to human, canine and murine hematopoietic cells. Marrow cells were exposed to the agent (2.7 x 10(-5) - 2.7 nM) for 4 h and then assayed in capillary (human) or Petri dish (canine, murine) clonal cultures. FCE 24517 inhibited myeloid (CFU-gm), erythroid (BFU-e, CFU-e) and megakaryocytic (CFU-meg) colony formation in a concentration-dependent manner. The progenitor cells were generally similar in their response to FCE 24517 within a species. Comparing the different progenitor cell response to FCE 24517, canine CFU-gm and CFU-e were 26- to 221-fold more sensitive to this drug's toxic effects than their human and murine counterparts. This was demonstrated by extremely low IC70 values for the canine CFU-gm (0.001 nM) and CFU-e (0.007 nM). Murine progenitors displayed 1.3- to 10.9-times higher IC70 values than human CFU-gm, BFU-e and CFU-e following 4 hr exposure to FCE 24517. The data demonstrated that a mouse model may better predict human in vitro myelotoxicity to FCE 24517 than beagle dogs.

In vitro toxicity of 3'-azido-3'-deoxythymidine, carbovir and 2',3'-didehydro-2',3'-dideoxythymidine to human and murine haematopoietic progenitor cells.

The myelotoxicities of three antiretroviral agents, 3'-azido-3'-deoxythymidine (AZT), carbovir (CBV) and 2',3'-didehydro-2',3'-dideoxythymidine (d4T), were evaluated in vitro with normal human and murine haematopoietic progenitor cells. These studies demonstrated that continuous AZT exposure was more inhibitory to human and murine colony formation than 1 h exposure, with murine and human progenitors similarly inhibited by continuous AZT exposure. These in vitro results on AZT's myelotoxicity correlate with both human and murine in vivo studies. CBV was only moderately toxic to human and murine cells following either 1 h or continuous exposure, with human and murine progenitors similarly suppressed by continuous CBV exposure. 1 h d4T exposure was less toxic to both human and murine marrow cells than continuous exposure and both species were equivalently inhibited when continuously exposed to d4T. In general, CBV was the least toxic agent to human and murine haematopoietic cells and AZT the most toxic. The study establishes CBV and d4T as less myelotoxic agents to human and murine haematopoietic progenitor cells in vitro than AZT which therefore could be considered as alternatives to AZT for the treatment of HIV infection.

Comparison of the in vitro toxicity of 2',3'-dideoxynucleosides to murine hematopoietic progenitor cells.

Four nucleoside analogues, 2',3'-dideoxyinosine (ddI), 2',3'-dideoxyadenosine (ddA), 2',3'-dideoxycytosine (ddC) and 5-fluoro-2',3'-dideoxycytosine (5-F-ddC), were evaluated for their potential in vitro myelotoxic effects on normal murine hematopoietic progenitor cells. Myeloid granulocyte-macrophage colony-forming units (CFU-gm), erythroid burst-forming units (BFU-e) and colony-forming units (CFU-e) and megakaryocytic (CFU-meg) progenitors were exposed to the agents for 1 h prior to culture in Petri dish assays or continuously throughout the entire culture period. At 10 microM, both ddA and ddI were moderately toxic (2-36% colony inhibition) to murine CFU-gm, BFU-e, CFU-e and CFU-meg following either 1 h or continuous exposure. Colony inhibition for the progenitors ranged from 2-31% at 10 microM for 1 h ddC or 5-F-ddC exposure. Continuous exposure to ddC was highly myelotoxic to murine hematopoietic progenitors with 100 microM suppressing colony formation 82-89%. At the same concentration and exposure time, 5-F-ddC inhibited colony formation 56-67%. Our results demonstrate that 1 h and continuous exposures to ddA and ddI were similarly myelotoxic to murine hematopoietic cells regardless of exposure time. In contrast, continuous ddC or 5-F-ddC exposure was more toxic to murine progenitors than 1 h exposure to these agents.

Comparative toxicity of fostriecin, hepsulfam and pyrazine diazohydroxide to human and murine hematopoietic progenitor cells in vitro.

The in vitro myelotoxic potentials of three investigational antitumor agents, Fostriecin, Hepsulfam and pyrazine diazohydroxide (PZDH), were evaluated utilizing clonogenic assays. Human and murine marrow cells were exposed to each drug for 1 hr prior to culture in microcapillary (human) or Petri dish (murine) assays. Fostriecin (0.22-220 microM), Hepsulfam (0.34-340 microM) and PZDH (0.68-680 microM) inhibited myeloid (CFU-gm), erythroid (BFU-e, CFU-e) and megakaryocytic (CFU-meg) colony formation in a concentration-dependent manner. CFU-e from both species were more sensitive to Fostriecin than the other progenitors and murine cells more sensitive overall to Fostriecin than their human counterparts. Murine CFU-e were also more sensitive to Hepsulfam than human CFU-e, with CFU-gm and BFU-e being similarly affected in both species. Human BFU-e were greatly inhibited by PZDH, whereas murine BFU-e were relatively resistant to its toxic effects. Fostriecin was the most toxic of the three antitumor agents, with PZDH the least toxic.

Utility of human bone marrow obtained incidental to orthopedic surgery for hematopoietic clonal assays.

We describe the establishment of a convenient method of acquiring human bone marrow cells for use in microcapillary clonal assays. Femoral epiphyseal and diaphyseal bone fragments and femoral canal reamings were collected incidental to total hip replacement surgery and cultured for human granulocyte-macrophage colony-forming units, erythroid burst-forming units and erythroid colony-forming units. This readily available source of normal human marrow provides an abundant quantity of hematopoietic progenitors of documented normalcy.

In vitro myelotoxicity of 2',3'-dideoxynucleosides on human hematopoietic progenitor cells.

Three nucleoside analogues, 2',3'-dideoxyadenosine (ddA), 2',3'-dideoxyinosine (ddI), and 2',3'-dideoxycytosine (ddC), were evaluated for their potential myelotoxic effects to normal human hematopoietic progenitor cells. The myeloid (granulocyte-monocyte colony-forming units, CFU-gm) and erythroid (erythroid burst-forming units, BFU-e: and erythroid colony-forming units, CFU-e) committed progenitor cells were exposed to the agents for a 1-h period prior to culture in a microcapillary assay or continuously exposed during the entire culture period. Both ddA and ddI (100 microM) were mildly toxic (less than 50% colony inhibition) to human CFU-gm, BFU-e, and CFU-e following either 1-h or continuous exposures. Marrow progenitor sensitivities to ddA and ddI were indistinguishable. Colony inhibition ranged from 47% to 67% for 1-h ddC exposure (100 microM), values that were comparable to ddA and ddI. Continuous exposure to ddC was highly myelotoxic to human hematopoietic progenitors, with concentrations of 10 and 100 microM suppressing colony formation by 79%-92% and 93%-97%, respectively. These results demonstrate that 1-h and continuous exposures to ddA and ddI were similarly myelotoxic to human hematopoietic cells, whereas a 1-h exposure to ddC was equivalent to ddA and ddI, yet continuous ddC exposure was extremely toxic to marrow cell progenitors.

Effects of L-phenylalanine mustard and L-buthionine sulfoximine on murine and human hematopoietic progenitor cells in vitro.

The effects of L-buthionine sulfoximine (L-BSO) and L-phenylalanine mustard (L-PAM), alone and in combination, on human and murine marrow were explored using in vitro clonogenic assays to establish whether enhanced myelotoxicity might limit the clinical utility of this potent chemotherapeutic combination. One-h exposure to L-PAM produced significant concentration-dependent colony inhibition, with 70% inhibitory concentration (IC70) values ranging from 4.5 to 7.2 microM for all hematopoietic progenitors assayed. The combination of L-PAM plus 4500 microM L-BSO for 1 h did not effectively alter the IC70 values derived for L-PAM alone. In studies where marrow cells were pretreated with L-BSO for 4 h and then L-PAM for 1 additional h, the IC70 values were decreased in both murine and human marrow progenitors compared to the L-PAM control, suggesting modest potentiation of myelotoxicity. The potentiation is not so significant as to preclude human studies with this combination. One- to 5-h exposure of marrow cells from both species to 4500 microM L-BSO was only mildly myelotoxic, producing colony reductions of 22-49%. However, continuous exposure to L-BSO produced concentration-dependent colony inhibition, with IC70 values of 70, 84, and 43 microM for murine colony-forming units-granulocyte/macrophage, blast-forming units-erythroid, and colony-forming unit-erythroid, respectively.

Microcapillary clonogenic assays for human marrow hematopoietic progenitor cells.

The capillary clonogenic cell assay was developed and adapted to culture myeloid and erythroid colonies from human bone marrow cells. The plating efficiencies for femoral bone marrow granulocyte-macrophage progenitors (CFU-gm), erythroid colony-forming units (CFU-e) and erythroid burst-forming units (BFU-e) were 0.143%, 0.229% and 0.141%, respectively. Standard bone marrow progenitor Petri dish assays require a total culture volume of 1 ml per dish, and as such are not suitable for the small numbers of cells often obtained from human bone marrow samples. The microcapillary assay as developed and standardized in our laboratory has the unique advantage of being able to utilize small numbers of cells. This technique is suitable for evaluating the myelotoxicity of investigational new anti-cancer and anti-HIV agents and for further investigation of the mechanisms underlying chemotherapy-induced bone marrow toxicity.