药用淫羊藿开花结实及种子休眠特性研究进展

针对药用淫羊藿开花结实与种子休眠特性等问题,从开花结实特性、时空与环境因素等对开花结实的影响、种子休眠特性及解除技术等方面进行了综述。从药用淫羊藿开花结实影响因素调查研究、种子丰产栽培技术研究、快速高效打破种子休眠技术研究、良种选育等方面,提出了提高药用淫羊藿植物结实率与种子发芽率的方法,为相关研究提供参考。     

Local expression of interleukin‐2 by B16 melanoma cells results in decreased tumour growth and long‐term tumour dormancy

The tumour microenvironment is complex containing not only neoplastic cells but also a variety of host cells. The heterogeneous infiltrating immune cells include subsets of cells with opposing functions, whose activities are mediated either directly or through the cytokines they produce. Systemic delivery of cytokines such as interleukin‐2 ( IL‐2) has been used clinically to enhance anti‐tumour responses, but these molecules are generally thought to have evolved to act locally in a paracrine fashion. In this study we examined the effect of local production of IL‐2 on the growth and the immune response to B16 melanoma cells. We found that the local production of IL‐2 enhances the number of interferon‐γ‐expressing CD8 T and natural killer cells in the tumour, as well as inducing expression of vascular cell adhesion molecule 1 on tumour vessels. These responses were largely absent in interferon‐γ knockout mice. The expression of IL‐2 in the tumour microenvironment decreases tumour growth despite also enhancing Foxp3⁺ CD4⁺ regulatory T cells and anti‐inflammatory cytokines such as IL‐10. Higher levels of IL‐2 in the tumour microenvironment eliminated the progressive growth of the B16 cells in vivo, and this inhibition was dependent on the presence of either T cells or, to a lesser extent, natural killer cells. Surprisingly however, the B16 tumours were not completely eliminated but instead were controlled for an extended period of time, suggesting that a form of tumour dormancy was established.     

T cell memory,anergy and immunotherapy in breast cancer

T cell immunity in breast cancer is suggested to play a role in tumor dormancy, a period of stability which can correspond to the time interval between primary treatment and tumor recurrence. Bone marrow in breast cancer patients seems to be particularly important because it is highly enriched with cancer specific memory T cells. Similar cells can be found in peripheral blood, but these appear to be functionally anergic. The immune system of primary operated breast cancer patients does not seem to be completely anergized. Bone marrow derived memory T cells can be reactivated ex vivo and show functional reactivity, including tumor rejection in NOD/SCID mice. Promising results were obtained from a postoperative phase-II active specific immunotherapy study. In this study, 32 patients treated with an optimal formulation of a virus-modified autologous tumor vaccine (ATV-NDV) appeared to have a significant 5-year survival benefit. Our results suggest that cancer reactive memory T cells which are enriched in the bone marrow of breast cancer patients, can be activated ex vivo via autologous dendritic cells pulsed with breast cancer tumor antigens, or they can be activated in situ via a tumor vaccine, which combines tumor antigens with virus infection. The findings should encourage further studies in breast cancer on active specific immunotherapy with tumor vaccines or adoptive immunotherapy with activated memory T cells.     

浙贝母低温解除休眠过程中过氧化物酶的电泳分析

为了探讨浙贝母低温解除休眠的生理机制，利用电泳方法研究了芽、鳞片近轴面表皮与鳞片内部组织３个部位在休眠解除过程中过氧化物酶同工酶的变化。发现芽和鳞片不同部位的同工酶谱带在解除休眠的不同时期均有变化，且芽和鳞片近轴面表皮的过氧化物酶活性明显高于鳞片内部组织。这些结果说明芽和鳞片都参与了休眠的解除。     

肿瘤休眠及其机制研究进展

肿瘤休眠(tumordormancy)是临床上普遍存在的一种现象,也是恶性肿瘤细胞的生物学特征之一,休眠细胞的长期存在是恶性肿瘤难以彻底根治的主要原因,也是导致肿瘤复发和远处转移的根源之一。本文从临床上发现肿瘤休眠存在、肿瘤休眠概念的演进、肿瘤休眠动物模型的建立、肿瘤休眠的分子及调控机制,以及肿瘤休眠的诱导、维持、再激活等方面进行了综述。旨在为开发诱导肿瘤休眠的药物和应用肿瘤休眠疗法根治肿瘤提供有益的线索。     

Abdominal wall recurrence of Hilar bile duct cancer 12 years after a curative resection: Report of a case

A 74-year-old woman was diagnosed with hilar bile duct cancer, and underwent a curative resection of the bile duct and the left and caudate lobes of the liver in 1995. Ten years later (April 2005), she noted a small mass in the abdominal wall. The mass slowly enlarged to reach 4 cm in diameter by January 2007. With a diagnosis of a possible recurrence of bile duct cancer, a laparotomy was thus performed. The abdominal wall tumor was buried in the rectus abdominis muscle and was tightly attached to the ileum. The lesion was resected en bloc with the associated rectus muscle and ileocecal region. A histopathological examination of the resected specimen revealed tubular adenocarcinoma that closely resembled the original primary bile duct cancer. In addition, the immunohistochemical staining pattern of the abdominal tumor was identical to that of the original bile duct cancer. This indicated that the abdominal tumor represented a local recurrence (probably due to peritoneal implantation) at 12 years after the resection of the hilar bile duct cancer. This case emphasizes that long-time surveillance is required for patients with bile duct cancer, even if they have survived without recurrence for more than 5 years after a curative resection.     

Influence of diet on metastasis and tumor dormancy

Tumor metastasis is responsible for most cancer deaths, and can occur after long periods of tumor dormancy. Information learned from experimental studies on tumor metastasis and dormancy is shedding light on mechanisms responsible and possible therapeutic approaches. ‘Seed’ (the cancer cell) and ‘soil’ (the microenvironment of the secondary organ) factors contribute to metastatic outcome. This review considers the possibility that various dietary components may affect both ‘seed’ and ‘soil’ compartments, thereby influencing the growth of metastases, and discusses an experimental study on dietary genistein that illustrates this concept. While studies on human diet are complex, the possibility that relatively non-toxic dietary intervention strategies could impact on metastasis and patient survival is attractive and worthy of further study in appropriate experimental models of metastasis and tumor dormancy.     

A seed coat bedding assay shows that RGL2-dependent release of abscisic acid by the endosperm controls embryo growth in Arabidopsis dormant seeds

Seed dormancy is an ecologically important adaptive trait in plants whereby germination is repressed even under favorable germination conditions such as imbibition with water. In Arabidopsis and most plant species, dormancy absolutely requires an unidentified seed coat germination-repressive activity and constitutively higher abscisic acid (ABA) levels upon seed imbibition. The mechanisms underlying these processes and their possible relationship are incompletely understood. We developed a "seed coat bedding" assay monitoring the growth of dissected embryos cultured on a layer of seed coats, allowing combinatorial experiments using dormant, nondormant, and various genetically modified seed coat and embryonic materials. This assay, combined with direct ABA measurements, revealed that, upon imbibition, dormant coats, unlike nondormant coats, actively produce and release ABA to repress embryo germination, whatever the embryo origin, i.e., from dormant, nondormant, or never dormant aba seeds, unable to synthesize ABA. The persistent high ABA levels in imbibed dormant seeds requires the permanent expression of the DELLA gene RGL2, where it remains insensitive to gibberellins (GA) unlike in nondormant seeds. These findings present the seed coat as an organ actively controlling germination upon seed imbibition and provide a framework to investigate how environmental factors break seed dormancy.     

Late recurrence (10 years or more) of malignant melanoma in south‐east Germany (Saxony) A single‐centre analysis of 1881 patients with a follow‐up of 10 years or more

Background Late recurrent melanoma (MM) is rare. Objective In the present study, we analysed the frequency of late recurrent MM in south‐eastern Germany. Patients and methods In our centre, 2314 MM patients were documented (1972–2001). A total of 1881 patients in stage I or II (AJCC) with a follow‐up of ≥10 years were selected and screened for late recurrence (≥10 years after diagnosis). Results Twenty patients were identified (1.1%), 13 women and 7 men, median age 44 years (age range 30–74 years). Nineteen suffered from cutaneous MM and one had a uveal MM (excluded from further analysis). The primary cutaneous MM occurred on the trunk (6), on the upper limb/shoulder (4), or on the lower limb (9). MM type was superficial spreading (13), nodular (2), acrolentiginous (1), lentigo maligna‐type (1) or unclassified (2). Tumour thickness varied from 0.33 mm to 9.5 mm (median 2.0 mm). Ulceration was seen in four, and spontaneous regression in two MM patients. Invasiveness into blood or lymphatic vessels occurred in seven MM patients. The largest period from primary diagnosis to recurrence was 25.1 years with a median of 13.9 years. Metastatic spread was loco‐regional (12 patients) or distant (7). Four patients were survivors and three of these had in‐transit metastases only. Overall survival was 14.7 ± 6.6 years. Statistical analysis could not identify factors significantly associated with late recurrence. Conclusions Late recurrence is a clinical sign of melanoma dormancy. We conclude that late recurrences argue for a lifelong follow‐up of melanoma patients.