Neoplastic transformation of the endocervix associated with downregulation of lactoferrin expression

Study of correlation between biochemical indicators and radiological diagnostic parameters of breast cancer

The aim of this work was to study the correlation between some biochemical parameters and parameters of radiological diagnostics for early diagnosis of breast cancer. 76 patients with breast cancer were examined. In 48 of them was diagnosed breast cancer, in 28 of them was diagnosed benign breast neoplasms. The age of patients ranged from 18 to 79 years. The control group consisted of 16 healthy women. Oncological markers (CEA, CA 15-3), some pro-inflammatory and inflammatory cytokines (IL-2, IL-6, IL-8, IL-10 and TNF-α) and lactoferrin were determined in serum by using enzyme-linked immunosorbent assay method. All patients underwent ultrasound with a combination of Doppler and X-ray mammography. Ultrasound examination assessed the estimation of tumor size, contours, echogenicity, echostructure, the presence and nature of vascularization of breast tumors, and also assessed the location of regional lymph nodes. During mammography, the contours and sizes of the detected tumor were determined, and the presence of microcalcifications was also taken into account. The results of the study showed that a statistically positive correlation between some biochemical parameters and parameters of radiological diagnostics was established.

Lactoferrin levels in cervical fluid from in vitro fertilization (IVF) patients - correlation with IVF parameters

Since our previous results suggest that lactoferrin (LF) might have roles in the reproductive process and that its levels might change in the female tract as a response to various factors, the aim of this investigation was to assess whether LF levels in cervical secretions correlate with reproductive parameters from in vitro fertilization (IVF) patients. Cervical fluid samples were obtained from 34 women under 40 years old enrolled for assisted reproduction techniques, and LF concentration was measured. The mean total protein concentration in all cervical fluid samples was 842.8 ± 116.9 µg/mL. The mean concentration of LF was 0.73 ± 0.06 ng LF/µg of total proteins. We observed that higher LF levels in cervical fluid correlated with lower IVF rates when all patients were analyzed; this negative correlation was also sustained when only patients ≥35 years were studied. The mean LF concentration in cervical fluid was significantly lower among patients with normal IVF rates than in those with values 50% or less. Using a LF cutoff value of 0.83 ng/μg of total proteins, the study revealed a significant association between the LF levels below 0.83 ng/µg of total proteins and IVF rates above 50%. LF levels in cervical mucus could potentially be used as a marker of fertilization outcome.

Mechanisms of Endogenous HIV-1 Reactivation by Endocervical Epithelial Cells

Pharmacological HIV-1 reactivation to reverse latent infection has been extensively studied. However, HIV-1 reactivation also occurs naturally, as evidenced by occasional low-level viremia ("viral blips") during antiretroviral treatment (ART). Clarifying where blips originate from and how they happen could provide clues to stimulate latency reversal more effectively and safely or to prevent viral rebound following ART cessation. We studied HIV-1 reactivation in the female genital tract, a dynamic anatomical target for HIV-1 infection throughout all disease stages. We found that primary endocervical epithelial cells from several women reactivated HIV-1 from latently infected T cells. The endocervical cells' HIV-1 reactivation capacity further increased upon Toll-like receptor 3 stimulation with poly(I·C) double-stranded RNA or infection with herpes simplex virus 2 (HSV-2). Notably, acyclovir did not eliminate HSV-2-induced HIV-1 reactivation. While endocervical epithelial cells secreted large amounts of several cytokines and chemokines, especially tumor necrosis factor alpha (TNF-α), CCL3, CCL4, and CCL20, their HIV-1 reactivation capacity was almost completely blocked by TNF-α neutralization alone. Thus, immunosurveillance activities by columnar epithelial cells in the endocervix can cause endogenous HIV-1 reactivation, which may contribute to viral blips during ART or rebound following ART interruption.IMPORTANCE A reason that there is no universal cure for HIV-1 is that the virus can hide in the genome of infected cells in the form of latent proviral DNA. This hidden provirus is protected from antiviral drugs until it eventually reactivates to produce new virions. It is not well understood where in the body or how this reactivation occurs. We studied HIV-1 reactivation in the female genital tract, which is often the portal of HIV-1 entry and which remains a site of infection throughout the disease. We found that the columnar epithelial cells lining the endocervix, the lower part of the uterus, are particularly effective in reactivating HIV-1 from infected T cells. This activity was enhanced by certain microbial stimuli, including herpes simplex virus 2, and blocked by antibodies against the inflammatory cytokine TNF-α. Avoiding HIV-1 reactivation could be important for maintaining a functional HIV-1 cure when antiviral therapy is stopped.

Effect of Heat Treatment on the Antitumor Activity of Lactoferrin in Human Colon Tumor (HT29) Model

To investigate the effect of heat treatment on the antitumor activity of lactoferrin in colon cancer cells and colon tumors, the HT-29 (human intestinal epithelial tumor cell) cell line was exposed to lactoferrin and various heat treatments. The impacts on cell proliferation, invasion, and migration were observed in vitro, and nude mice bearing HT29 tumors were administered lactoferrin and underwent various heat treatments in vivo. In the HT29 cell proliferation test using transwell and scratch analyses, lactoferrin (20 mg/mL) without or with heat treatment (50 and 70 °C) significantly inhibited cell proliferation, migration, and invasion (compared with the control, p < 0.05), while lactoferrin with heat treatment (100 °C) did not affect these parameters. In vivo, HT29 tumor weight was significantly reduced in the lactoferrin (without heat treatment and with 50 and 70 °C treatment) groups (1.59 ± 0.20, 1.67 ± 0.25, and 2.41 ± 0.42 g, compared with the control, p < 0.05), and there was no significant difference between the control (3.73 ± 0.33 g) and the 100 °C treatment group (3.58 ± 0.29 g). Moreover, 100 °C heat treatment reduced inhibition of the VEGFR2/VEGFA/PI3K/Akt/Erk1/2 angiogenesis pathway by lactoferrin. In summary, HT29 tumors were effectively suppressed by lactoferrin via inhibition of VEGFR2/VEGFA/PI3K/Akt/Erk1/2 pathway, and heat treatment affected the antitumor activity of lactoferrin in a temperature-dependent manner.

Lactoferrin Exerts Antitumor Effects by Inhibiting Angiogenesis in a HT29 Human Colon Tumor Model

To investigate the effect and potential mechanisms of lactoferrin on colon cancer cells and tumors, HT29 and HCT8 cells were exposed to varying concentrations of lactoferrin, and the impacts on cell proliferation, migration, and invasion were observed. Cell proliferation test showed that high dosage of lactoferrin (5-100 mg/mL) inhibited cell viability in a dose-dependent manner, with the 50% concentration of inhibition at 81.3 ± 16.7 mg/mL and 101 ± 23.8 mg/mL for HT29 and HCT8 cells, respectively. Interestingly, migration and invasion of the cells were inhibited dramatically by 20 mg/mL lactoferrin, consistent with the significant down regulation of VEGFR2, VEGFA, pPI3K, pAkt, and pErk1/2 proteins. HT29 was chosen as the sensitive cell line to construct a tumor-bearing nude mice model. Notably, HT29 tumor weight was greatly reduced in both the lactoferrin group (26.5 ± 6.7 mg) and the lactoferrin/5-Fu group (14.5 ± 5.1 mg), compared with the control one (39.3 ± 6.5 mg), indicating that lactoferrin functioned as a tumor growth inhibitor. Considering lactoferrin also reduced the growth of blood vessels and the degree of malignancy, we concluded that HT29 tumors were effectively suppressed by lactoferrin, which might be achieved by regulation of phosphorylation from various kinases and activation of the VEGFR2-PI3K/Akt-Erk1/2 pathway.

Immunoexpression of lactoferrin in triple-negative breast cancer patients: A proposal to select a less aggressive subgroup

Triple-negative breast cancer (TNBC) indicates a subset of breast carcinomas that does not express estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2). According to the literature, TNBCs are aggressive tumors, characterized by a high incidence of recurrence and a high risk of disease progression. Lactoferrin (LF) is a single-chain, iron-binding glycoprotein of ~700 amino acids, which is involved in a wide range of biological activities, including iron-trafficking and carcinogenesis. The present study aimed to assess LF expression in human TNBC samples and the possible correlation with clinico-pathological parameters associated with biological aggressiveness. LF immunohistochemical expression was investigated in formalin-fixed, paraffin-embedded samples of human TNBC. Cases were analyzed according to an intensity distribution (ID) score, and only those showing an ID score of >2 were considered as positive for LF. LF immunostaining was encountered in 26.15% cases. A significant correlation was found between LF expression and a low Ki-67 labeling index (P=0.040), the absence of recurrence (P=0.010) and alive status (P=0.020). LF may assist in identifying a subset of TNBC with less aggressive biological behavior. The meaning of LF expression in TNBC remains unclear and is controversial. The present findings indicated that LF expression is correlated with a low growth fraction in these tumors. Thus, it is possible that the inhibition of the LF axis may be a valid therapeutic target for TNBC, and this should be confirmed by future studies.

Lactoferrin-endothelin-1 axis contributes to the development and invasiveness of triple-negative breast cancer phenotypes

Triple-negative breast cancer (TNBC) is characterized by the lack of expression of estrogen receptor-α (ER-α), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2). However, pathways responsible for downregulation of therapeutic receptors, as well as subsequent aggressiveness, remain unknown. In this study, we discovered that lactoferrin (Lf) efficiently downregulates levels of ER-α, PR, and HER-2 in a proteasome-dependent manner in breast cancer cells, and it accounts for the loss of responsiveness to ER- or HER-2-targeted therapies. Furthermore, we found that lactoferrin increases migration and invasiveness of both non-TNBC and TNBC cell lines. We discovered that lactoferrin directly stimulates the transcription of endothelin-1 (ET-1), a secreted proinvasive polypeptide that acts through a specific receptor, ET(A)R, leading to secretion of the bioactive ET-1 peptide. Interestingly, a therapeutic ET-1 receptor-antagonist blocked lactoferrin-dependent motility and invasiveness of breast cancer cells. The physiologic significance of this newly discovered Lf-ET-1 axis in the manifestation of TNBC phenotypes is revealed by elevated plasma and tissue lactoferrin and ET-1 levels in patients with TNBC compared with those in ER(+) cases. These findings describe the first physiologically relevant polypeptide as a functional determinant in downregulating all three therapeutic receptors in breast cancer, which uses another secreted ET-1 system to confer invasiveness. Results presented in this article provide proof-of-principle evidence in support of the therapeutic effectiveness of ET-1 receptor antagonist to completely block the lactoferrin-induced motility and invasiveness of the TNBC as well as non-TNBC cells, and thus, open a remarkable opportunity to treat TNBC by targeting the Lf-ET-1 axis using an approved developmental drug.

Lactoferrin in human tumours: immunohistochemical investigations during more than 25 years

Lactoferrin (LF) is an iron-binding glycoprotein of the transferrin family, today known to have multifunctional physiological activities. In humans, under normal conditions, LF has been found in blood, mucosal secretions, gastrointestinal fluids, urine and mostly in milk and colostrum. The first pioneering immunohistochemical report about LF distribution in human tissues dated in 1978; successively, many studies have been performed to analyze the LF immunohistochemical pattern in different normal and neoplastic tissues. In this review, we present data from literature concerning the evidence of LF in tumors together with those by us obtained during more than 25 years; the immunohistochemical applications to human neoplastic tissues have been done to investigate the LF pathogenetic role as well as its activity in cancer. After a systematic analysis of LF immunoreactivity in different human districts, a possible explanation for its presence and function has been modulated for each site or tissue, according to experimental evidences obtained either by in vivo as well as by in vitro studies.

The anti-papillomavirus activity of human and bovine lactoferricin

Human papillomavirus (HPV) cause common warts, laryngeal papilloma and genital condylomata and is necessary for the development of cervical cancer. We have previously found that lactoferrin has antiviral activity against HPV-16 and others have demonstrated that lactoferricin, an N-terminal fragment of lactoferrin, has inhibitory activities against several viruses. Two cell lines and two virus types, HPV-5 and HPV-16, were used to study if lactoferrin and lactoferricin could inhibit HPV pseudovirus (PsV) infection. We demonstrated that bovine lactoferrin (bLf) and human lactoferrin (hLf) were both potent inhibitors of HPV-5 and -16 PsV infections. Among the four lactoferricin derivatives we analyzed, a 15 amino acid peptide from bovine lactoferricin (bLfcin) 17-31 was the most potent inhibitor of both HPV-5 and HPV-16 PsV infection. Among the other derivatives, the human lactoferricin (hLfcin) 1-49 showed some antiviral activity against HPV PsV infection while bLfcin 17-42 inhibited only HPV-5 PsV infection in one of the cell lines. When we studied initial attachment of HPV-16, only bLfcin 17-42 and hLfcin 1-49 had an antiviral effect. This is the first time that lactoferricin was demonstrated to have an inhibitory effect on HPV infection and the antiviral activity differed depending on size, charge and structures of the lactoferricin.

Prevention of carcinogenesis and cancer metastasis by bovine lactoferrin

Increasing attention is being paid to chemopreventive agents for individuals at high risk of cancer. We have concentrated on bovine lactoferrin (bLF), an 80 kDa iron-binding glycoprotein known to have anti-microbial and immunoprotective effects. Lactoferrin is particularly abundant in colostrum, and is also present in tears, saliva and seminal and uterine secretions. However, only little is known regarding its influence on carcinogenesis. We have shown preventive effects of bLF and its fragment peptide, lactoferricin (bLFcin), consisting of a 25 amino acid sequence without iron binding capacity, on chemically-induced colon carcinogenesis in the rat and transplanted carcinoma cell metastasis in the mouse. The mechanisms are wide-spectrum, including elevation of caspase-1 and IL-18 in the small intestine, enhancement of the cell killing activity of cytotoxic T and natural killer (NK) cells, and anti-inflammatory and anti-angiogenic effects. It also inhibits the induction of liver CYP1A2, a carcinogen activating enzyme, and induces apoptosis in the colon epithelium of carcinogen treated rats. Thus, bLF possesses multi-functional potential to suppress carcinogenesis and is a good candidate for practical application in humans.

Pepsin-Digested Bovine Lactoferrin Induces Apoptotic Cell Death With JNK/SAPK Activation in Oral Cancer Cells

Lactoferrin, a member of the transferrin family, is iron-binding and a strongly cationic 76 kDa glycoprotein. In breast milk it is secreted in high concentrations from glandular epithelia and is also present in other exocrine fluids including saliva. In the present study, we examined the biological mechanisms of apoptosis induced by pepsin-digested-lactoferrin peptide (Lfn-p) in the human oral squamous cell carcinoma cell line SAS. We found that treatment with Lfn-p induced cell death with apoptotic nuclear changes, preceded by the cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP) in the apoptotic cells. Treatment with Lfn-p induced phosphorylation of extracellular signal-regulated kinase (ERK1/2), a member of the MAP kinase family, at early stages of apoptosis. Another MAP kinase, c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK), was also phosphorylated by treatment with Lfn-p. Pretreatment of SAS cells with SP600125, a JNK/SAPK inhibitor, diminished Lfn-induced apoptosis, as assessed by determining released lactate dehydrogenase activity. On the other hand, the MEK1 inhibitors PD98059 or U0126 showed no effect on repression of cell death, but rather an increase. These results suggest that JNK/SAPK activation may play an important role in Lfn-p-induced apoptotic cell death of human oral squamous cell carcinoma cells.

Endocervical cancer is associated with an increase in the ligands and receptors for transforming growth factor-beta and a contrasting decrease in p27(Kip1)

OBJECTIVE

The aim of this study was to investigate the relationship between the expression of the TGF-beta ligands and TGF-beta receptors to the expression of p27(Kip1), a TGF-beta-regulated gene, in endocervical cancer.

METHODS

To examine the expression of TGF-beta and p27(Kip1) in malignant transformation of the uterine endocervix, a panel of 23 formalin-fixed and paraffin-embedded human cervical specimens, including 8 with benign endocervical glands, 8 with cervical adenocarcinoma in situ, and 7 with cervical adenocarcinomas, was used. Tissues were immunostained with polyclonal antibodies that react specifically with TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1).

RESULTS

Immunostaining for TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1) was detected in normal endocervix, with the TGF-betas showing weak cytoplasmic staining, while p27(Kip1) showed strong nuclear staining. Expression of TGF-beta increased significantly upon neoplastic transformation with the TGF-beta ligands and receptors showing strong cytoplasmic staining in adenocarcinoma in situ compared to normal endocervix. Interestingly, expression of TGF-beta was lower in adenocarcinoma than in adenocarcinoma in situ, but still significantly higher than in normal endocervix. TGF-beta 2 and TGF-beta 3 showed higher levels of immunostaining than TGF-beta 1 in adenocarcinomas. In contrast, p27(Kip1) protein expression decreased with progressive malignancy, with lower p27(Kip1) protein levels detected in adenocarcinoma than in adenocarcinoma in situ, while normal endocervix showed the highest level of p27(Kip1) protein expression.

CONCLUSION

Elevated expression of the TGF-beta ligands and receptors is found in both cervical adenocarcinoma in situ and adenocarcinoma compared to normal endocervix. In contrast, a progressive decrease in p27(Kip1) occurs upon neoplastic transformation of the normal endocervix to cervical adenocarcinoma. These results suggest that neoplastic transformation of the endocervix may be related to dysregulation of TGF-beta and p27(Kip1) seen as an elevation of TGF-beta and a reduction of p27(Kip1) expression that may lead to loss of cell cycle control.

Milk and dairy products in cancer prevention: focus on bovine lactoferrin

Milk and dairy products constitute an important part of the western style diet. A large number of epidemiological studies have been conducted to determine effects of consumption on cancer development but the data are largely equivocal, presumably reflecting the different included components. It has been proposed that whereas fats in general could promote tumor development, individual milk fats like conjugated linoleic acid could exert inhibitory effects. There is also considerable evidence that calcium in milk products protects against colon cancer, while promoting in the prostate through suppression of circulating levels of 1,25-dihydroxyvitamin D3. Whey protein may also be beneficial, as shown by both animal and human studies, and experimental data have demonstrated that the major component bovine lactoferrin (bLF), inhibits colon carcinogenesis in the post-initiation stage in male F344 rats treated with azoxymethane (AOM) without any overt toxicity. The incidence of adenocarcinomas in the groups receiving 2% and 0.2% bLF were thus 15% and 25%, respectively, in contrast to the 57.5% control value (P<0.01 and P<0.05, respectively). Results in other animal models have provided further indications that bLF might find application as a natural ingredient of milk with potential for chemoprevention of colon and other cancers.