Biological treatment of Kidney cancer

blair (1997 years) and Statistics United States in recent years, every 10 million people die of cancer patients in 1994 to 200.9 persons / 10 million in 1970 compared to 189.6 persons / 100,000. The mortality rate is higher than in 1994, anti-1970, shows 20 years on the treatment of cancer is not a breakthrough. In cancer prevention and control work, the conclusion is that prevention is better than cure [1].

     According to the U.S. National Cancer Institute (NCI) RCC meeting summed up the topic (1997), the incidence of renal cell carcinoma (1975 to 1990) increased by 54%, only in 1996 that 30,000 new cases diagnosed renal cancer. In the same year, 12,000 patients died of the disease. Smoking is an important risk factor. High blood pressure, high-protein diet, taking diuretics and anti-hypertensive drugs also have some impact. Nearly half of all kidney cancer patients to the hospital the first time, that is, when treatment is already late, about 40% of patients with postoperative recurrence or metastasis, did not receive treatment in 3-year survival rate of less than 5%, a poor prognosis [2,3].

     Tumor suppressor gene (VHL) and Wilm tumor suppressor gene (WT1) are considered to be the pathogenesis of renal cell carcinoma. WT1 adjustable proto-oncogene bcl-2 and c-myc [4]. Chromosome analysis, was found in renal cell carcinoma in the short arm of chromosome No. 3, that there exist VHL gene. In the renal clear cell carcinoma, VHL mutations and a high percentage of heterozygosity at chromosome 3P13 discovered missing persons DNA sequence of up to 97%, while the VHL mutations in 50% ~ 60%. Further found that VHL gene can regulate vascular endothelial growth factor (VEGF), renal cell carcinoma is very rich blood supply, VEGF expression is high, inhibit VHL may reduce kidney cancer angiogenesis [3-6]. 1996 cloned FHIT gene (for fragile histidine riad), the gene located on chromosome 3P-14, 2, and the yeast gene order is similar to almost all lung cancer and esophageal cancer, 85% of renal cell carcinoma, 76% of cervical cancer , 40% of colon cancer, 30% of the FHIT gene in prostate cancer are missing, it is considered to be a new tumor suppressor gene.

     Telomerase activity in renal cell carcinoma chromosome There were also increased, suggesting that the enzyme in the pathogenesis of renal cell carcinoma play a role, also as a marker for renal cell carcinoma.

     Renal cell carcinoma on radiotherapy and chemotherapy are not sensitive to the treatment of advanced kidney cancer to bring some difficulties, renal cell carcinoma with multi-drug resistance gene (MDR-1), the P170 protein in cells can enter the cancer cells material pump chemotherapy out of the cell, so in general the effect of chemotherapy, "10%. The efficacy of immunotherapy have a certain, IL-2 is considered the standard treatment for renal cell carcinoma metastasis agents, IL-2 for the T cell growth factor on cancer cells have no direct anti-tumor cytotoxic effect, but can be expanded T-cell the number of stimulating activation of the T-cell growth, enhance the immune response in patients [2,3].

     rIL-2

     iL-2 was FDA approved in 1992, applied to the treatment of advanced renal cell carcinoma, Rosenberg (1985) first used high-dose IL-2 treatment of renal cell carcinoma, 255 cases of patients through the clinical summary, high-dose IL-2 to induce some Patients with tumors all mitigation (CR) or partial remission (tumor shrinkage 50%, PR) [2,7]. The overall response rate is about 15% ~ 20%, all to alleviate the average survival time of 40 months, some of remission for 24 months. "75% of the CR can be maintained in patients with tumor-free period of three years, a few even more than 5 years. Rosenberg used IL-2 dose of 720000IU/kg, intravenous injection, every 8 hours to once a week 5 times. Side-effects, the initial treatment of patients, more than half need to use the step-up drugs to maintain blood pressure, 7% of patients with endotracheal intubation for assisted breathing, a small number of patients need dialysis treatment line, the death rate nearly 4%. Performance in patients with high fever, chills, vomiting, diarrhea, associated with heart, lung, liver and renal insufficiency. Renal insufficiency usually as prerenal azotemia, the main pathophysiological mechanism of increased capillary permeability, plasma extravasation, resulting in decreased blood volume, organ interstitial edema, low blood pressure, water retention, and oliguria, saying that it as a capillary leak syndrome (capillary leak syndrome), after stopping side effects can be restored in the near future [2]. Last 5 years with high-dose IL-2 treated patients, there was no case of IL-2 therapy died [7]. Side effects of this treatment program is not only big, but drug prices are also very expensive, would have difficulty in the country to promote the use. But in terms of metastatic renal cell carcinoma, IL-2 although the tumor can not be cured, but can inhibit its biological processes, and even enable tumor temporarily subsided, it should be significant progress on the treatment of renal cancer. Mankaff et al [8] reported 1 case was high-dose IL-2 in patients with PR after treatment using FDG (18F-Flurodeoxy glucose)-PET scan observation, found that cancer can not uptake FDG, prompts cancer cells had died, surgery and found a huge necrotic tumor, pathological examination of cancer cells can not live. 30 months have been observed in patients with no evidence of tumor recurrence, and has resumed full-time job. Although the surviving patients with tumors in the PR, but also achieve a similar effect of CR.

     Although the high-dose IL-2 treatment of renal cell carcinoma has been more than 10 years, but the overall response rate failed to further enhance the side effects are more obvious, therefore, should be further in search of better treatment programs.

     yang et al [9] had 260 patients with 3 different doses of IL-2 and different application methods in order to observe its efficacy: (1) high-dose intravenous injection group, 720000IU/kg every 8 hours. (2) Small-dose intravenous injection group, 72000IU/kg every 8 hours. (3) subcutaneous injection group, 120000IU / day, 5 times a week.

     Results: The remission rate of high-dose group 20% (3% CR, 17% PR); low-dose group 15% (7% CR, 8% PR). Mitigation of high-dose group took longer than low-dose group, but significant toxicity, 52% of the patients exhibited hypotension, required injection of vasoconstrictor. Hypotension occurred while the small-dose group were 3%. On the remission rate, remission duration and overall survival in terms of large dose IL-2 is superior to intravenous injection of low-dose group, but the remission rate of low-dose intravenous injection group also obtained good results, it think it is the treatment an effective way to transfer kidney cancer. Subcutaneous group of toxicity and response rate with low-dose intravenous groups of similar, due to the amount of subcutaneous injection of low toxicity and can be injected at home, has been used increasingly for everyone.

     INF-α

     Which had already begun in 1983, interferon INF-α treatment of renal cell carcinoma metastasis. According to more than 900 cases of clinical conclusion, remission rate of 18.4%, remission period of 6 to 10 months, but those few CR. General daily 10 ~ 20MU/m2, mild symptoms, small size and a better tumor response. In the mouse tumor model, INF-α can enhance MHC expression in tumor cells, so that tumor antigens can be presented to T cells, activated T cells. INF-α may also reduce the tumor bFGF expression, reducing tumor angiogenesis. Recently even think that INF-α can signal transduction and transcription (STATs) affect cell proliferation [10].

     iL-2 and INF-α combination treatment of advanced kidney cancer, remission rate of nearly 20%, about 5% of patients exhibited CR, slightly better than the efficacy of high-dose IL-2 or its equivalent.

     iNF-α plus CRA (Cis-retinoic acid)

     With 3 ~ 9MU / day INF-α2a plus daily 1mg/kgCRA, 43 patients, 13 cases of remission (30%), 3 cases were CR, 10 Li PR, mean remission time 22 months. Tip-added effect of combined treatment may be compared with INF-α alone and better [3].

     Biochemotherapy

     atzpodien (1996) reported use of subcutaneous injection of IL-2 while giving the INF-α and 5FU Treatment of Metastatic renal cell carcinoma, and achieved good results. Because subcutaneous injection of IL-2, greatly reduced toxicity. All patients can be treated at home. From October 1988 to June 1993, 120 patients after treatment, 13 patients (11%) tumor complete remission, 32 patients (28%) partial remission, with a total remission rate was 39%. 18 cases of PR patients, tumor reduction 90%, CR in patients with tumor-free period of 8 to 47 months, with an average of 15 months; PR decreased in patients with tumors 2 to 31 months, an average of 11 months. 5% of the CR patients completed the long-term without evidence of recurrence after treatment, the dose for the subcutaneous injection of IL-2 (20MU/m2), INF-α (6 ~ 9MU/m2) and intravenous injection 5FU750mg/m2 [11]. The patients who no poisoning. Another group reported that remission rates were 47%. Gebrosky, etc. [12] reported 21 cases of advanced kidney cancer, using only daily 5FU200mg/m2 intravenously and INF-α-2b1 × 106IU subcutaneously, resulting in 9 cases (43%), ease, CR4 cases (19%), PR5 cases of (24%). CR, the average survival time of 195 weeks, PR in patients with 184 weeks. This group of patients without the use of IL-2, 5FU dose is smaller, but the treatment lasted for 6 months. The information on the treatment of advanced kidney cancer remission rate has grown from the original 20% to 40%.

     Adoptive immunotherapy

     Adoptive immunotherapy often will have anti-tumor properties of lymphocytes in vitro cell proliferation in order to expand its numbers, with some biological response modifiers in patients re-enter the body, in order to improve the tumor response rate and longer remission time.

     1. Tumor-infiltrating lymphocytes (TIL): the removal of the tumor tissue suspension is made with the IL-2 lines in vitro, after a period of time after the death of renal cancer cells, T lymphocytes in continued growth, and finally up to two the number of TILs ~ 3 × 1011, and then the proliferation of TILs enter the patient. TILs to tumor antigens has been activated CTLs (cytotoxic T lymphocyte), specificity of tumor target cells, enter the body can return tumor. LAK cells, there is no such function. TILs than in animal experiments that the anti-tumor effect of LAK cells is 50 ~ 100 times, the University of California (U-CLA) using low-dose intravenous IL-2, Canada, and TILs with INF-α treatment of advanced renal cell carcinoma, 62 patients, 5 cases of CR (9.1%), 14 Li PR (25.5%), no significant toxicity, as the school has been the standard treatment of advanced kidney cancer treatment options [13].

     2. Dendritic cells (DC): Dendritic cells are the recent immunology and cancer research workers, one of the topics of most concern. DC levels in the body very little, less than 1% of human blood cells, but with a strong immune activation, in the past emphasized that the immune response to antigens and T cells occur in between, in fact only the antigen and the T-cell immune response is still not sufficient to cause , DC is the cause of the initiation of the cellular immune response (initia-tor), the surface of dendritic cells, there are many long and thin (> 10μm) of the filament itself can move, it is suitable to capture antigen, and then presented to T cells, DC Get antigens, from an immature DC into mature DC, a major change in morphogenesis, while capturing antigen dysfunction, activation of T cell function is strengthened. The two main feature is the DC to capture antigen, and then presented to T cells, activated T cells. Whether in vivo or in vitro, only a small number of DC can stimulate a strong T-cell response. A dendritic cell can activate 100 ~ 3000 T cells, so DC as antigen-presenting cells, macrophages and B compared with cells more effective. DC surface MHC Ⅰ and MHC Ⅱ histocompatibility antigens compared with mononuclear cells and B lymphocytes 10 ~ 100 times higher, but also with the second signal to activate T-cell co-stimulatory protein B7.1/CD80 and B7.2/CD86 as well as other adhesion molecules, DC themselves can produce IL-12, INF-α and other important cellular factors [14,15]. In addition, DC can still secrete DC specific chemokine DC factor (DC-CKI), the factors on naive T cells (NaiveT cells) is particularly attractive [16]. Another important feature of DC for the DC into the blood, to eventually return to the secondary lymphoid organs, the antigen was transmitted to stay in the area the majority of naive T cells, naive T cells are activated to fight the tumor CTLs. Albert recently reported that human DC can be effectively antigens from apoptotic cells, such as tumor and graft antigens presented to CD8 cells to become CTL [17].

     A general decline in MHC expression in tumor cells, B7 also declined. It is simply not sufficient to activate the T cells, tumor antigens, with antigen-presenting cells still need to get an effective immune response, DC in this regard play an important role.

     In vitro, with GM-CSF and IL-4 to DC cultured, make DC a large number of amplification. IL-4 for DC growth, differentiation must cytokine, GM-CSF only as a survival factor during training [16]. In vitro amplification, can be transduced tumor-specific antigen or antigens to DC and then enter the body with the DC fusion [18]. DC can also be amplified in the body, FLT-3L (fetal liver tyrosine kinase recep-torligand) is a strong hematopoietic cell growth factor, FLT-3 with given physical increase in DC number and activity of animal experiments (lynch) Daily injection of recombinant human FLT-3L, after a substantial increase in DC-mice, 40% of the fiber sarcoma disappeared completely. The rest of the tumor growth is significantly suppressed. Amplification in vivo than in vitro is simple, conducting preliminary clinical trials [19,20].

     Finally, CTLs encounter with the tumor cells, the secretion of perforin and granzyme B, activated within the cytoplasm of the cysteine protease (cysteine protease) also known as Caspase, can cell skeleton, DNA cut, so that apoptosis in cancer cells [21].

     Antiangiogenic

     Anti-tumor angiogenesis for the treatment of a swelling new concept, any solid tumor growth and metastasis depend on new blood vessel formation (angiogenesis), the lack of new blood vessel formation, tumor growth is difficult to more than 1mm3, only after the formation of new blood vessel the tumor can be rapid growth, Folkman1971 years, i.e. to proceed in this research.

     The normal only about 0.01% of vascular endothelial cells in the proliferation. Normal vascular endothelial cells can secrete angiogenesis inhibiting substance throm bospondin to keep the blood vessels in the resting state. Once activated oncogene, p53 or VHL mutations, then the increase in angiogenic factors. Angiogenic factors in renal cell carcinoma are mainly vascular endothelial growth factor (VEGF) and bFGF. Only the role of VEGF in the vascular endothelium, on the other cells had no growth-promoting effect, it is the formation of new blood vessels specificity. VEGF in promoting angiogenesis at the same time can enhance the permeability of blood vessels, so that easy access to blood vessel cells to distant metastasis. The formation of new blood vessels can be regarded as angiogenesis inhibiting the formation of the material and the material balance of vascular disorders result.

     In the nascent vascular endothelial, there is a specific VEGF receptor tyrosine kinase (receptor tyro-sine kinase, RTK) also known as FLT-1 (fetal liver tyrosine kinase). FLT-1 expression in normal vascular endothelium is very low, while in the vicinity of tumors and tumor blood vessels were showed high expression of the tumor in the FLT-1 and VEGF binding to VEGF receptor than the other kind of KDR (kinase domain region) Strong 100 times, so VEGF-FLT-1RTK system on the formation of new blood vessels, has a pivotal role. Using VEGF antibody almost completely blocked the growth of tumors and angiogenesis, the eradication of a vascular endothelial cell growth of cancer cells can prevent 100 [22,23].

     Clinically, also found that tumor microvessel density in patients with cancer metastasis and survival-related.

     In addition to cancer cells secrete angiogenic factors, the same time, also produce other anti-angiogenic substances, some non-tumor tissue can also create anti-angiogenic substances, such as INF-α, INF-inducible protein -10 and the CXC chemokine, etc. [3]. Have clinical significance in the O'Reilly et al [24] in the Lewis lung cancer found in angio-statin. angiostatin as a relative molecular mass of 38000 protein, the equivalent of human plasminogen (plasminogen) in a fragment of the blood vessels to prevent the formation of strong activity [24]. Subsequently Gatley et al [25] (1996) found that a variety of human prostate cancer cell line PC-3, DU-145 and Ln-CaP and so are able to produce serine protease (serineprotease), it can be broken down into plasminogen angiostatin, and that the development of human prostate cancer may be related to this relatively slow. the formation of inhibition, accounting for 2% of body weight of tumors after treatment by the above-mentioned preparations, reduce size of 1mm3 into the microscopic lesions, tumor size was reduced 150-fold, and some tumors were completely disappeared, microscope, could not find any cancer cells. Withdrawal no recurrence 11 months after the lung is also no transfer of control group were found to have lung metastasis. On various occasions found no resistance, but also no toxic reaction, being clinical observation.

     Tumor angiogenesis in cellular and molecular structure has changed. Neovascularization in sub-integrin cell adhesion (integrin) as αVβ3, and the original vascular cell integrin different. Integrin is not only the cell-cell adhesion protein, with the skeleton inside the cell relative to the joint and serves as a cell outside and inside the cell outward messenger on cell function has an important influence. It is felt that αVβ3 also be used as targets for treatment of cancer, Arg-Gly-Asp (RGD) can be selectively combined with αVβ3, it can be anti-cancer drugs combined with the RGD transported to the new blood vessels, may also be directly αVβ3 single polyclonal antibodies to treat cancer. Brooks et al [28,29] report using αVβ3mAb new blood vessels can rapidly cause cell apoptosis, whereas normal blood vessels had no original influence on the human tumor also has the same effect.

     Monoclonal antibody

     Renal cell carcinoma-specific antigen G250 has been identified and cloned, and now able to conduct research G250 kidney cancer specific antigen as a tumor vaccine preparation. Anti-G250 monoclonal antibody (mAbG250) with all of the renal clear cell carcinoma and clear cell carcinoma of the majority of the non-binding, but not react with normal kidney cells. With 131I labeled mAbG250 can kidney imaging, compared with conventional imaging techniques more sensitive. More than 90% of the tumor, whether primary or liver, lung, bone and lymph node metastasis can imaging imaging. Confirmed by surgery and CT and MRI have not been found in metastatic cancer can also be 131ImAbG250 imaging, the smallest tumor found only 8mm. Because of high levels of tumor uptake mAbG250, it could be considered for renal cell carcinoma with iodine labeled monoclonal antibody radiation therapy [30,31].

     IL-12

     iL-12 in animal experiments, have a stronger anti-tumor effects in clinical practice have tried to treat metastatic kidney cancer, but have caused death in two cases, so testing was suspended. IL-2 and IL-12 combination, or IL-12 + IL-18 may be more effective than the two alone. IL-12 also has anti-tumor angiogenesis effect of INF-α may enhance anti-tumor effect, but clinical application of tumor response rate was less obvious, are now further observe the effect [3,32].

     Gene Therapy

     Cancer gene therapy is still at an early stage of development, the world's more than 200 kinds of clinical programs, so far without a program that is successful. In 1990 the world's first case of adenosine deaminase (ADA) deficiency were once advertised as a successful example of gene therapy is still the need for continued injection of synthetic ADA, shows that gene therapy is not successful. The main obstacle to gene therapy is the lack of an effective gene vector, gene transfer can lead to cancer [33]. Huang (1998 years) have tried a similar chylous lipoprotein as a carrier, allow gene transduction 10% success rate. The liposomes can only use up to 0.5% [34]. Harrington (1997 years) the success of the trial is about normal chromosomes 1 / 5 the size of the artificial chromosome (HAC), the HAC transduction to the mouse cell function after six months remained stable, the cells continued mitosis. So now wish to adopt the transduction of human artificial chromosomes to replace the existing treatment or transduction gene on chromosome 3 of treatment of renal cell carcinoma [35].

     The pathogenesis of cancer is a complex, according to Volgestein genetic model of colon cancer, cancer gene mutation and the absence of multiple tumor suppressor gene is the main features of carcinoma occur only for the replacement of a single gene to treat cancer, is difficult success. Often used experimental study of wild-type p53 gene therapy for cancer, that p53-induced cell apoptosis is an important individual to prevent tumor defense mechanisms.

     volgestein laboratory was established in 1997 in p53-induced apoptosis molecular model. p53 in hypoxia, radiation, ultraviolet radiation, and chemotherapy drugs to stimulate, may be activated. Transcriptional activation of p53 may be 14 kinds of genes that create proteins that can produce large amounts of reactive oxygen species factor (ROS), damage mitochondria membrane, so that the membrane potential and membrane permeability changes (PT), the membrane holes The Dow increased (megapore), mitochondria of cytochrome C and Ca2 + outflow and finally activation of the cysteine protease within the cytoplasm also known as Caspase and CAD (caspase activated DNA se), but will cut the DNA so that cell apoptosis [ 36,37]. Transfected with p53 gene therapy for advanced lung cancer has been reported, but the effect is not significant, tumor gene therapy breakthrough in the short term is hard. NCl in 1997, claims that by the beginning of the next century, the strategic goals of gene diagnosis, gene diagnosis of the next century, medical advances will pave the way for gene therapy still need to do a lot of basic work, it is estimated 10 years before we can make progress