Immunoexpression of VEGFR-3, but not the immunoexpression of VEGF-C or lymphatic density, is correlated with metastasis in lower lip squamous cell carcinoma.

The purpose of this study was to evaluate the immunoexpression of vascular endothelial growth factor C (VEGF-C) and VEGF receptor 3 (VEGFR-3) and their correlation with intratumoural lymphatic density (ILD) and peritumoural lymphatic density (PLD) in metastatic and non-metastatic lower lip squamous cell carcinoma (LLSCC). Twenty-five LLSCC with regional nodal metastasis and 25 LLSCC without metastasis were selected. The percentages of VEGF-C and VEGFR-3 staining in each tumour core and at the deep invasive front were assessed. PLD and ILD were determined using anti-podoplanin antibody. Immunohistochemical findings were correlated with nodal metastasis, clinical staging, local recurrence, clinical outcome, and histological grade. Cytoplasmic immunoexpression of VEGFR-3 in the tumour core was associated with metastasis (P=0.009), patient death (P=0.008), and histological grade (P<0.005). PLD, ILD, and VEGF-C expression showed no significant associations with clinicopathological parameters (P>0.05). PLD and ILD were not significantly correlated with the immunoexpression of VEGF-C or VEGFR-3 (P>0.05). There was a significant positive correlation between PLD and ILD (P=0.004), and between cytoplasmic immunoreactivity of VEGF-C and VEGFR-3 (P=0.011). These results suggest an important role for VEGFR-3 in the progression of LLSCC, and highlight the possible influence of its expression on the prognosis of these tumours. ILD and PLD may not be associated with lymph node metastasis in LLSCC.

Inoculation of somatic embryos of sweet potato with an arbuscular mycorrhizal fungus improves embryo survival and plantlet formation.

Responses of somatic embryos of sweet potato (Ipomoea batata (L.) Poir., cv. White Star) at different developmental stages to in vitro inoculation with Glomus etunicatum (Becker and Gerdemann) (isolate INVAM FL329) were evaluated. Somatic embryos were grown in glass tubes containing sterilized vermiculite and sand. A layer of natrosol plus White's medium was used as a carrier for arbuscular mycorrhizal (AM) fungal spores. Survival of embryos inoculated with AM fungi was significantly (P < 0.05) greater than that of noninoculated embryos at the rooted-cotyledonary-torpedo and rooted-elongated-torpedo developmental stages. Mycorrhizae significantly (P < 0.05) increased plantlet formation only when inoculation occurred at the rooted-elongated-torpedo developmental stage. The growth stage at which the embryos were inserted into the glass tubes exerted a significant influence upon plantlet formation, and plantlet formation was further enhanced by inoculation with G. etunicatum. Plantlet formation was greatest at the rooted-elongated-torpedo stage. These results demonstrate that inoculation of somatic embryos with AM fungi improves embryo survival and plantlet formation, and could enhance use of somatic embryos as synthetic seeds.